Pyridine derivatives, herbicidal composition containing the same, and method for killing weeds

Abstract

The present invention provides a novel pyridine derivative having the following general formula and its salt: ##STR1## wherein R is a hydrogen atom, a hydroxyl group, an alkoxy group, an alkoxyalkoxy group, and derivatives;R.sup.1 and R.sup.2 may be the same or different, and are a hydrogen atom, an alkoxy group, a halogen atom, an alkylamino group, a dialkylamino group;Z is a methine group or a nitrogen atom;X.sup.1 is an acylamino group, a cycloalkyl group, a halogen-substituted alkoxy group, an alkenyloxy group, an alkynyloxy group, an alkoxycarbonyl group, an alkylamino group, a dialkylamino group, a phenyl group.The pyridine derivative and its salt of the present invention achieve an excellent herbicidal effect on annual and perennial weeds growing in paddy fields and upland fields at a very small dosage.The pyridine derivative and its salt of the present invention have safety to rice, wheat, cotton and corn, and can be suitably applied as a herbicide to a field where these plants are cultivated.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a novel pyridine derivative and its salt, a method for preparing the same, a herbicidal composition containing the same as an effective ingredient, and a method for killing weeds.

2. Discussion of Background

Heretofore, as a pyridine carboxylic acid derivative having a herbicidal activity, there were known 3-(4,6-dimethoxypyrimidin-2-yl)oxypicolinic acid derivative (Japanese Unexamined Patent Publication No. 84/1989), pyrimidyloxypicolinic acid derivative and pyrimidyloxyisonicotinic acid derivative (Japanese Unexamined Patent Publication No. 121973/1990 and 149567/1990).

However, these references do not describe a nicotinic acid derivative having a heterocyclic ring-containing substituent at the 2-position as in the compound of the present invention.

Heretofore, many herbicides have been developed, and have contributed to the saving of energy for the agricultural operations and to the improvement of the production efficiency. However, in their practical use, such herbicides have various problems. For example, a herbicide achieving a herbicidal effect specially at a low dose is desired in view of environmental problems. Particularly, a desirable herbicide should have a herbicidal effect for killing perennial weeds such as johnsongrass (Sorghum halepense) and purple nutsedge (Cyperus rotundus) which are widely distributed on agricultural lands throughout the world and are hardly killed. Furthermore, a herbicide having a satisfactory selectivity and safety to crop plants is particularly desired in respect of agricultural management.

Up to now, the known compounds as described in the above references do not always have satisfactory herbicidal effects.

The present inventors have conducted extensive research on nicotinic acid derivatives with an aim to develop a compound having a satisfactory herbicidal activity, and as a result, have found that the pyridine derivative of the present invention which is a nicotinic acid derivative having a heterocyclic ring-containing substituent at the 2-position, has an excellent herbicidal activity for killing annual and perennial weeds including gramineous weeds, cyperaceous weeds and broadleaf weeds by water treatment of rice fields and soil treatment or foliage treatment of upland fields, and also has a satisfactory safety to crop plants including rice, wheat and the like. The present invention has been accompanished on the basis of this discovery.

DISCLOSURE OF THE INVENTION

The pyridine derivative of the present invention is defined by the general formula (I): ##STR2## wherein R is a hydrogen atom, a hydroxyl group, an alkoxy group, an alkoxyalkoxy group, an acyloxyalkoxy group, a benzyloxy group which may be substituted, a trimethylsilylethoxy group, an alkylsulfonylamino group, an alkylthio group, a phenoxy group which may be substituted, a phenylthio group which may be substituted or an imidazolyl group;

R.sup.1 and R.sup.2 may be the same or different, and are a hydrogen atom, an alkoxy group, a halogen atom, an alkylamino group, a dialkylamino group, a halogen-substituted alkoxy group or an alkyl group; Z is a methine group or a nitrogen atom; X.sup.x is an acylamino group, a cycloalkyl group, a halogen-substituted alkoxy group, an alkenyloxy group, an alkynyloxy group, an alkoxycarbonyl group, an alkylamino group, a dialkylamino group, a phenyl group, a substituted phenyl group, a benzyloxy group which may be substituted, a benzylthio group which may be substituted, a benzyl group which may be substituted, a phenoxy group which may be substituted, a phenylthio group which may be substituted, an alkoxyiminoalkyl group, an acyl group, an alkylthio group, an arylamino group which may be substituted, a carboxyl group, a benzoylamino group, or a group having the formula, ##STR3## (wherein R.sup.1, R.sup.2 and Z are as defined above, and W is an oxygen atom, a sulfur atom, a NH group or a group of the formula, >NC(O)B (wherein B is a hydrogen atom or an alkoxy group)); and X.sup.2 is a hydrogen atom, a halogen atom, a halogen-substituted alkyl group, an alkyl group, a cycloalkyl group, a haloalkoxy group, an alkenyloxy group, an alkynyloxy group, an alkoxycarbonyl group, an alkoxy group, an alkylamino group, a dialkylamino group, an acylamino group, a phenyl group, a substituted phenyl group, a benzyloxy group which may be substituted, a benzylthio group which may be substituted, a benzyl group which may be substituted, a phenoxy group which may be substituted, a phenylthio group which may be substituted, an alkoxyiminoalkyl group, an acyl group, an alkylthio group, an arylamino group which may be substituted, a carboxyl group, a benzoylamino group or a group having the formula, ##STR4## (wherein R.sup.1, R.sup.2, W and Z are as defined above).

The present invention relates to a pyridine derivative and its salt.

Also, the present invention further relates to a method for preparing the pyridine derivative, a herbicidal composition containing the pyridine derivative or its salt as an effective ingredient and a method for killing weeds.

In the general formula (I), examples of the alkoxy group of R include a straight-chain or branched C.sub.1 .about.C.sub.7 alkoxy group such as a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group, a n-butoxy group, an isobutoxy group, a s-butoxy group, a t-butoxy group, a n-pentyloxy group, an isopentyloxy group, a s-pentyloxy group, a t-pentyloxy group, a n-hexyloxy group, a 2,2-dimethylpropoxy group, a 2-methylbutoxy group, a 2-ethylbutoxy group, a 3,3-dimethylbutoxy group, and a 1,3,3-trimethylbutoxy group.

Examples of the alkoxy group of R.sup.1 and R.sup.2 are as defined in the above alkoxy group of R. Examples of the halogen atom include chlorine, bromine, fluorine and iodine. Examples of the alkylamino group include a straight-chain or branched C.sub.1 .about.C.sub.3 alkylamino group such as a methylamino group, an ethylamino group, a n-propylamino group and an isopropylamino group. Examples of the dialkylamino group include a straight-chain or branched C.sub.1 .about.C.sub.3 dialkylamino group such as a dimethylamino group, a diethylamino group, a methylethylamino group, a di-n-propylamino group and a diisopropylamino group. Examples of the haloalkoxy group include a straight-chain or branched C.sub.1 .about.C.sub.7 haloalkoxy group having a part or the whole part of the alkoxy group substituted with the above-mentioned halogen atoms, such as a difluoromethoxy group and a chloromethoxy group. Examples of the alkyl group include a straight-chain or branched C.sub.1 .about.C.sub.7 alkyl group such as a methyl group, an ethyl group, n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a s-butyl group, a t-butyl group, a n-pentyl group, an isopentyl group, a s-pentyl group, a t-pentyl group, a n-hexyl group, a 2,2-dimethylpropyl group, a 2-methylbutyl group, a 2-ethylbutyl group, a 3,3-dimethylbutyl group and a 1,3,3-trimethylbutyl group.

Examples of the halogen atom, alkylamino group and dialkylamino group of X are as defined in the above-mentioned halogen atom, alkylamino group and dialkylamino group of R.sup.1 and R.sup.2. Examples of the halogen-substituted alkyl group include a halogen-substituted alkyl group having a part or the whole part of a straight-chain or branched C.sub.1 .about.C.sub.3 alkyl group substituted with the above-mentioned halogen atoms, such as a difluoromethyl group, a chloromethyl group and a tribromomethyl group. Examples of the alkyl group are as defined in the above-mentioned alkyl group of R.sup.1 and R.sup.2. Examples of the alkoxy group are as defined in the above-mentioned alkoxy group of R.sup.1 and R.sup.2.

Examples of the haloalkoxy group are as defined in the above-mentioned haloalkoxy group of R.sup.1 and R.sup.2.

Examples of the cycloalkyl group include a C.sub.3 .about.C.sub.7 cycloalkyl group such as a cyclopropyl group, a cyclopentyl group and a cyclohexyl group.

Examples of the alkenyloxy and alkynyloxy groups include C.sub.2 .about.C.sub.8 alkenyloxy and alkynyloxy groups.

Examples of the substituted phenyl group include a substituted phenyl group, a part or the whole part of the phenyl group being substituted with the above-mentioned halogen, lower alkyl, lower alkoxy, alkylamino, dialkylamino, halogen-substituted alkyl, haloalkoxy, nitro, hydroxy, alkoxyalkoxy, alkoxycarbonylalkoxy, alkylthioalkoxy, benzyloxy, cyano, phenoxy, substituted phenoxy, alkylthio, alkoxyalkyl or ethynyl group, such as a p-chlorophenyl group and a 3-tolyl group. Examples of a preferable compound include a compound of the general formula (I) wherein R is a hydroxyl group, a methoxy group, an ethoxy group, a benzyloxy group, an ethoxymethoxy group, a pivaloyloxymethoxy group or a trimethylsilylethoxy group; R.sup.1 and R.sup.2 are the same or different and are a hydrogen atom, a chlorine atom, a methyl group, a methoxy group, a dimethylamino group or a halogen-substituted methoxy group; X.sup.1 is a phenyl group, a halogen-substituted phenyl group, a methyl-substituted phenyl group, a methoxy-substituted phenyl group or a mono or dimethylamino group; X.sup.2 is a hydrogen atom; Z is a methine group or a nitrogen atom.

The compound of the present invention of the general formula (I) can be prepared, for example, by the following preparation method, but the present invention is not limited to these methods.

PREPARATION METHOD 1 ##STR5## (wherein L is a halogen atom, an alkylsulfonyl group, a benzylsulfonyl group which may be substituted, an alkylsulfonate group, a haloalkylsulfonate group or a benzylsulfonate group which may be substituted; and X.sup.1, X.sup.2 R, R.sup.1 R.sup.2 and Z are as defined above.)

The compound of the general formula (I) can be prepared by reacting a compound of the formula (A), with a compound of the formula (B) in the presence of a base having an amount of at least equivalent amount in an appropriate solvent at a temperature in the range from room temperature to the boiling point of the solvent for from 0.5 to 24 hours.

Here, as the base, there may be employed an alkali metal such as lithium metal, sodium metal or potassium metal, organic lithium reagents such as n-butyl lithium or lithium diisopropylamide (LDA); an alkali metal or an alkaline earth metal hydride such as sodium hydride, potassium hydride or calcium hydride; an alkali metal alkoxide such as potassium t-butoxide; an alkali metal carbonate such as sodium carbonate or potassium carbonate; or a metal hydroxide such as sodium hydroxide or potassium hydroxide.

As the solvent, there may be employed a hydrocarbon solvent such as hexane, benzene, toluene or xylene; a halogenated hydrocarbon solvent such as dichloromethane or chloroform; an ether solvent such as diethyl ether, tetrahydrofuran or 1,4-dioxane; an ester solvent such as methyl acetate and ethyl acetate; a ketone solvent such as acetone and ethyl methyl ketone; an aprotic polar solvent such as N,N-dimethylformamide, N,N-dimethylacetamide and dimethylsulfoxide; and others such as acetonitrile or the like.

The compound of the formula (A) can be prepared in the accordance with the methods disclosed in "Journal of Medicinal Chemistry" (vol. 6, p. 294, 1963; and vol. 7, p. 17, 1964), "Berichte" (74B, p. 1111, 1941), "Liebigs Ann. Chem." (371, 1979) and the like, but can also be prepared by the following method. ##STR6## (wherein R.sup.3 R.sup.4 and R.sup.5 are the same or different, and are a hydrogen atom, a lower alkyl group, a lower alkoxy group, an alkylamino group, a dialkylamino group, a phenyl group or a substituted phenyl group; R.sup.6 is a hydrogen atom or an alkyl group; and L is as defined above.)

The compound of the formula (IV) can be prepared by heating a compound of the formula (II) and an acetal compound of the formula (III) in the presence or absence of an inorganic or organic base for from 0.1 to 10 hours in an appropriate solvent including an alcohol such as methanol or ethanol, an ether such as tetrahydrofuran, an aprotic polar solvent such as N,N-dimethylformamide or acetonitrile ("Archiv der Pharmazie" vol. 318, p. 481, 1985).

Also, the compound of the formula (V) can be prepared by reacting the compound of the formula (IV) with hydrogen bromide or hydrogen chloride gas in an inert solvent such as dichloroethane or toluene or acetic acid within a temperature range from 0.degree. C. to the boiling point of the solvent, preferably from 10.degree. C. to 50.degree. C.

Furthermore, the compound of the formula (VI) can be prepared by reacting the above prepared compound of the formula (V) with thiourea within a temperature range from 50.degree. C. to 120.degree. C. for 0.5 to 10 hours in the presence of water and a mineral acid such as hydrochloric acid or sulfuric acid, treating the resultant product with an alkaline material such as sodium hydroxide or potassium hydroxide, and then acidifying the resultant product with an acid such as hydrochloric acid (see Japanese Unexamined Patent Publication No. 275562/1989). The product thus obtained contains a small amount of sulfide and disulfide in addition to the aimed thiol compound.

PREPARATION METHOD 2 ##STR7## (wherein L, X.sup.1, X.sup.2, R, R.sup.1, R.sup.2, and Z are as defined above.)

The compound of the formula (I) can also be prepared by reacting a compound of the formula (C) with a compound of the formula (D) in the presence of a base having an amount of at least equivalent amount in an appropriate solvent for 0.5 to 24 hours within a temperature range from room temperature to the boiling point of the solvent. The base and the solvent used may be the same in the above Preparation Method 1.

PREPARATION METHOD 3

Reaction Formula 4 ##STR8## (wherein R.sup.7 is an alkyl group or a trimethylsilylethyl group; and X.sup.1, X.sup.2, Z, R.sup.1 R.sup.2 are as defined above.)

The compound of the formula (F) can be prepared by reacting the compound of the formula (E) in the presence of a base having an amount of at least equivalent amount in an appropriate solvent such as water or a solvent containing water for 0.5 to 24 hours at a temperature of from room temperature to the boiling point of the solvent and then acidifying the resultant product.

Here, as the base, there may be employed a metal hydroxide such as sodium hydroxide or potassium hydroxide; a carbonate such as sodium carbonate or potassium carbonate; a hydrogen carbonate such as sodium hydrogen carbonate or potassium hydrogen carbonate. In the case of trimethylsilyl ethyl ester, the compound of the formula (E) may be prepared by the reaction with tetrabutylammonium fluoride or potassium fluoride.

As the solvent, there may be employed a hydrocarbon solvent such as hexane; a halogenated hydrocarbon solvent such as dichloromethane or chloroform; an alcohol solvent such as methanol, ethanol or 2-propanol; an ether solvent such as diethyl ether, tetrahydrofuran or 1,4-dioxane; a ketone solvent such as acetone or ethyl methyl ketone; an aprotic polar solvent such as N,N-dimethylformamide, N,N-dimethylacetamide or dimethylsulfoxide; and others such as acetonitrile or the like.

PREPARATION METHOD 4 ##STR9## (wherein M.sup.+ is 1 equivalent amount of alkali metal, alkaline earth metal, ammonium or organic ammonium ion; and X.sup.1, X.sup.2, Z, R.sup.1 and R.sup.2 are as defined above.)

The compound of the formula (G) can be prepared by reacting the compound of the formula (F) with an equivalent amount of a base in an appropriate solvent for 0.5 to 24 hours within a temperature range from room temperature to the boiling point of the solvent.

Here, as the base, there may be employed an alkali metal hydride such as sodium hydride and potassium hydride; an alkali metal alkoxide such as sodium methoxide or sodium ethoxide; an alkali metal or alkaline earth metal carbonate such as sodium carbonate and calcium carbonate; an alkali metal or alkaline earth metal hydroxide such as sodium hydroxide, potassium hydroxide or calcium hydroxide; an alkali metal hydrogencarbonate such as sodium hydrogencarbonate and potassium hydrogencarbonate; and an organic amine such as isopropylamine.

As the solvent, there may be employed a hydrocarbon solvent such as benzene, toluene and xylene; a halogenated hydrocarbon solvent such as dichloromethane or chloroform; an alcohol solvent such as methanol, ethanol and 2-propanol; an ether solvent such as diethyl ether, tetrahydrofuran or dioxane; an aprotic polar solvent such as N,N-dimethylacetamide or dimethylsulfoxide; and others such as acetonitrile, water or the like.

PREPARATION METHOD 5 ##STR10## (wherein Q is a halogen atom, a cyano group, an imidazolyl group or a substituted amidinoxy group; and R, R.sup.1, R.sup.2, X.sup.1, X.sup.2 and Z are as defined above.)

The intermediate compound of the formula (H) for preparing the compound of the present invention of the formula (I) can be prepared by reacting the compound of the formula (F) with a condensation agent having an amount of at least equivalent amount in an appropriate solvent for 0.5 to 24 hours within a temperature range from -10.degree. C. to the boiling point of the solvent. The intermediate compound thus prepared may be separated or may not be separated, and the compound of the formula (I) can be prepared by reacting the intermediate compound with a compound of the formula (J) and a base having an amount of at least equivalent amount in an appropriate solvent for 0.5 to 24 hours within a temperature range from -10.degree. C. to the boiling point of the solvent.

As the condensation agent, there may be employed a thionyl chloride, oxalic acid dichloride, chlorocarbonic acid ester, carbonyldiimidazole, cyanophosphoric acid ester, carbodiimide or the like. Here, the base and the solvent may be the same as used in the Method 1 as described above.

PREPARATION METHOD 6 ##STR11## (wherein R.sup.8 is an alkyl group, an alkoxyalkyl group, an acyloxyalkyl group or a benzyl group which may be substituted; and R.sup.1, R.sup.2, L, X.sup.1, X.sup.2 and Z are as defined above.)

The compound of the formula (I) can be prepared by reacting the compound of the formula (F) with the compound of the formula (K) in the presence of one equivalent or more of base in an appropriate solvent for 0.5 to 24 hours within a temperature range from -10.degree. C. to the boiling point of the solvent. Here, the base and the solvent may be the same as used in the Method 1 as described above.

[BEST MODE FOR CARRYING OUT THE INVENTION]

In the following, the method for preparing the compound of the present invention is more concretely explained by giving Examples.

PREPARATION EXAMPLE 1

Synthesis of methyl 4-(4-chlorophenyl)-2-(4,6-dimethoxypyrimidin-2-ylthio)nicotinate (Compound No. 8)

A mixture of 73.9 g (0.24 mol) of 2-bromo-4-(4-clorophenyl)nicotinic acid and 22.0 g (0.29 mol) of thiourea in 100 ml of 5% HCl and 150 ml of acetic acid was stirred at 100.degree. C. for 2 hours. The mixture was poured into water and 400 ml of 50% sodium hydroxide was added to the resultant mixture, and the mixture was stirred at room temperature for 30 minutes. The mixture was then acidified with 20% HCl, and the crystal thus precipitated was filtrated out and washed with water. The washed crystal was then dried to obtain a crude crystal of 2-mercapto-4-(4-chlorophenyl)nicotinic acid.

The crude crystal thus obtained, 66.0 g (0.30 mol) of 4,6-dimethoxy-2-methylsulfonylpyrimidine and 104.0 g (0.75 mol) of potassium carbonate were dissolved in 500 ml of dimethylsulfoxide, and stirred at 80.degree. C. for 2 hours. After the temperature was restored to room temperature, 68.0 g (0.48 mol) of methyl iodide was added to the reaction mixture, and the resultant reaction mixture was stirred at room temperature for 30 minutes. The reaction mixture was then poured into water, and extracted with 1 l of ethyl acetate. The extract was washed with water and a saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate, and concentrated. The concentrate was purified by silica gel column chromatography (eluting solvent: ethyl acetate/hexane=1/4) to obtain 19.0 g of a white crystal of the aimed product.

Yield: 19.2%, Melting point: 138.degree.-141.5.degree. C.

PREPARATION EXAMPLE 2

Synthesis of 4-(4-chlorophenyl)-2-(4,6-dimethoxypyrimidin-2-ylthio)nicotinic acid (Compound No. 9)

16.8 g (0,040 mol) of methyl 4-(4-chlorophenyl)-2-(4,6-dimethoxypyrimidin-2-ylthio)nicotinate was dissolved in 150 ml of dimethylsulfoxide, and 35 ml (0,070 mol) of 2N sodium hydroxide added with stirring at 60.degree. C. After stirring at 60.degree. C. for 30 minutes, the mixture was poured into water, and washed twice with ethyl acetate. The aqueous layer was acidified with 10% hydrochloric acid, and extracted with 500 ml of ethyl acetate. The extract was washed with water and a saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate, and concentrated. The concentrate was washed with methanol and isopropyl ether to obtain 11.5 g of a white crystal of the aimed product.

Yield: 70.8%, Melting point: 219.degree.-223.degree. C.

PREPARATION EXAMPLE 3

Synthesis of pivaloyloxymethyl 4-(4-fluorophenyl)-2-(4,6-dimethoxypyrimidin-2-ylthio)nicotinate (Compound No. 19)

A mixture of 0.70 g (0.0019 mol) of 4-(4-fluorophenyl)-2-(4,6-dimethoxypyrimidin-2-ylthio)nicotinic acid and 0.50 g (0.0036 mol) of potassium carbonate in 10 ml of N,N-dimethylformamide was stirred at room temperature for 1 hour. Thereafter, 0.34 g (0.0022 mol) of chloromethyl pivalate was further added to the resultant mixture, and the mixture was stirred at room temperature for 2 hours. The mixture was then poured into water, and extracted with 50 ml of ethyl acetate. The extract was washed with water and a saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate, and concentrated. The concentrate was purified by silica gel column chromatography (eluting solvent: ethyl acetate/hexane=1/4) to obtain 0.81 g of a yellowish thick syrup-like aimed product.

Yield: 88 0%, Refractive index (n.sub.D.sup.20): 1.5615

PREPARATION EXAMPLE 4

Synthesis of methyl 4-(4-isopropoxyphenyl)-2-(4,6-dimethylpyrimidin-2-ylthio)nicotinate (Compound No. 74)

20.0 g (0.059 mol) of 2-bromo-4-(4-isopropoxyphenyl)nicotinic acid and 5.5 g (0.072 mol) of thiourea were dissolved in 40 ml of 5% HCl and 60 ml of acetic acid, and stirred at 100.degree. C. for 2 hours. The reaction mixture was poured into water, and 200 ml of 50% sodium hydroxide was added thereto, and the mixture was stirred at room temperature for 30 minutes. The mixture was then acidified with 20% HCl and the thus precipitated was filtrated out and washed with water and then dried. The above synthesized crude crystal [2-mercapto-4-(4-isopropoxyphenyl)nicotinic acid] and 11.1 g (0.060 mol) of 4,6-dimethyl-2-methylsulfonylpyrimidine, and 25.0 g (0.18 mol) of potassium carbonate were dissolved in 200 ml of dimethylsulfoxide and stirred at 80.degree. C. for 2 hours. After restoring the temperature to room temperature, 16.8 g (0.12 mol) of methyl iodide was added to the reaction mixture, and the mixture was stirred at room temperature for 30 minutes. The reaction mixture was then poured into water, and was extracted with 500 ml of ethyl acetate. The organic layer was washed with water and a saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate, and concentrated. The concentrate was purified by silica gel column chromatography (eluting solvent: ethyl acetate/hexane=1/2) to obtain 6.5 g of a light-yellowish thick syrup-like aimed product.

Yield: 26.7%, Refractive index (n.sub.D.sup.20): 1.5965

PREPARATION EXAMPLE 5

Synthesis of sodium 4-(4-chlorophenyl)-2-(4,6-dimethoxypyrimidin-2-ylthio)nicotinate (Compound No. 167)

To a solution of 0.50 g (0.0012 mol) of 4-(4-chlorophenyl)-2-(4,6-dimethoxylpyrimidin-2ylthio)nicotinic acid in 7 ml of ethanol was added 0.30 g (0.0016 mol) of methanol solution of 28% sodium methylate at room temperature. After addition, the mixture was further stirred at room temperature for 20 minutes. The crystal thus precipitated was filtrated, and washed with ethanol and dried to obtain 0.46 g of a white powder of the aimed product.

Yield: 86.0%, Melting point: 244.degree.-247.degree. C.

PREPARATION EXAMPLE 6

Synthesis of 4-(3-chlorophenyl)-2-(4,6-dimethoxypyrimidin-2-ylthio)-N-methylsulfonylnicotinamide (Compound No. 161)

To a solution of 3.0 g (0.0074 mol) of 4-(3-chlorophenyl)-2-(4,6-dimethoxypyrimidin-2-ylthio)nicotinic acid in 30 ml of N,N-dimethylformamide was added 1.50 g (0.0093 mol) of carbonyldiimidazole with stirring, and the mixture was stirred at room temperature for 24 hours. To a suspension of 0.60 g (0.0015 mol) of 60% sodium hydride in 30 ml of N,N-dimethylformamide was added 1.8 g (0.0019 mol) of methanesulfonamide and stirred at 80.degree. C. for 2 hours. Thereafter, the above prepared N,N-dimethylformamide solution of carbonylimidazole of nicotinic acid was added thereto at room temperature, and the mixture was stirred at 80.degree. C. for 2 hours. The reaction mixture was then poured into water, and washed with 50 ml of ethyl acetate. Thereafter, the aqueous layer was acidified with 10% HCl, and extracted with 100 ml of ethyl acetate. The organic layer was washed with water and a saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate, filtrated and concentrated. The concentrate was purified by silica gel column chromatography (eluting solvent: ethyl acetate/hexane=1/1) to obtain 3.0 g of a light-yellowish glass-like aimed product.

Yield: 81.3%, Melting point: 54.degree.-58.degree. C.

REFERENCE EXAMPLE 1

Synthesis of 1-cyano-1-methoxycarbonyl-2-(4-dimethylamino)-2-(4-methoxyphenyl)-1,3-butadiene (Intermediate No. 5)

85.0 g (0.44 mol) of 1-cyano-l-methoxycarbonyl-2-(4-methoxyphenyl)-1-propylene and 79 g of 1,1-dimethoxytrimethylamine (0.66 mol) were dissolved in 200 ml of methanol and refluxed for 30 minutes with stirring. The reaction mixture was cooled with ice water to precipitate a crystal, which was then filtrated out. The crystal thus obtained was washed three times with 100 ml of methanol, and dried to obtain 103.6 g of a greenish yellow aimed product.

Yield: 81.4%, Melting point: 175.degree.-178.degree. C.

REFERENCE EXAMPLE 2

Synthesis of methyl 2-bromo-4-(4-chlorophenyl)nicotinate (Intermediate No. 56)

To a solution of 80.0 g (0.28 mol) of 1-cyano-1-methoxycarbonyl-4-(N,N-dimethylamino)-2-(4-chlorophenyl)-1,3-butadiene in 100 ml of acetic acid, an acetic acid solution of 25% HBr was then gradually added dropwise at room temperature with stirring. After the dropwise addition, the resultant mixture was stirred at room temperature for 3 hours. The reaction mixture was then poured into ice water to precipitate a crystal. The crystal thus precipitated was filtrated out and washed with water and dried to obtain 75.0 g of a white crystal of the aimed product.

Yield: 83.5%, Melting point: 73.degree.-76.degree. C.

REFERENCE EXAMPLE 3

Synthesis of 2-bromo-4-(4-chlorophenyl)nicotinic acid (Intermediate No. 57)

To a solution of 50.0 g (0.15 mol) of methyl 2-bromo-4-(4-chlorophenyl)nicotinate in 300 ml of dimethylsulfoxide, 60 ml of 30% sodium hydroxide was added and stirred at 80.degree. C. for 3 hours. The mixture was then poured into water and washed with 300 ml of ethyl acetate. Thereafter, the aqueous layer was acidified with 10% HCl to precipitate a crystal, which was then filtrated out. The crystal thus precipitated was washed with water and isopropyl ether, and dried to obtain 41.0 g of a white crystal of the aimed product.

Yield: 85.7%, Melting point: 204.degree.-208.degree. C.

In the following, examples of the compound of the present invention thus obtained are illustrated in Table 1. The abbreviation marks in the Table respectively mean the following groups.

Compound Nos. given in the Table will be referred to the subsequent description in the specification.

Pym: 4,6-Dimethoxypyrimidin-2-yl group Tri: 4,6-Dimethoxy-s-triazin-2-yl group Ph: Phenyl group (g): 2-(4,6-Dimethylpyrimidin-2-yl)thio group (h): 2-(4-Methoxy-6-methyl-s-triazin-2-yl)thio group (i): 2-(4-Methoxy-6-methylpyrimidin-2-yl)thio group (m): 2-(4-Chloro-6-methoxypyrimidin-2-yl)thio group

Also, examples of the intermediate products as prepared above, are given in the following Table 2 and Table 3.

TABLE 1__________________________________________________________________________ ##STR12## Physical properties Melting point (.degree.C.)Com- orpound Refractive indexNo. R X.sup.1, X.sup.2 A (n.sub.D.sup.20)__________________________________________________________________________ 1 OH 4-Ph 2-SPym 191-195 2 OCH.sub.3 4-Ph 2-SPym 115.about.117 3 OCH.sub.2 OCOC.sub.4 H.sub.9 -t 4-Ph 2-SPym 1.5712 4 ##STR13## 4-Ph 2-SPym 1.5670 5 OH 4-Ph, 6-CH.sub.3 2-SPym 154.about.159 6 OH ##STR14## 2-SPym 179.about.183.5 7 OCH.sub.3 ##STR15## 2-SPym 149.about.151 8 OCH.sub.3 ##STR16## 2-SPym 138.about.141.5 9 OH ##STR17## 2-SPym 219.about.223 10 OCH.sub.3 ##STR18## 2-SPym 1.6042 11 OH ##STR19## 2-SPym 181.about.184 12 OCH.sub.3 ##STR20## 2-SPym 1.5961 13 OH ##STR21## 2-SPym 95.about.99 14 OCH.sub.3 ##STR22## 2-SPym 151.about.154 15 OH ##STR23## 2-SPym 193-197 16 OCH.sub.3 ##STR24## 2-SPym 120.about.123 17 OH ##STR25## 2-SPym 155.5.about.158 18 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR26## 2-SPym 1.5640 19 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR27## 2-SPym 1.5615 20 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR28## 2-SPym 1.5619 21 OCH.sub.3 ##STR29## 2-SPym 134.about.137.5 22 OH ##STR30## 2-SPym 178-181 23 OCH.sub.3 ##STR31## 2-SPym 135.about.139 24 OH ##STR32## 2-SPym 169.about.172 25 OCH.sub.3 ##STR33## 2-SPym 90.5.about.94 26 OH ##STR34## 2-SPym 178.about.180 27 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR35## 2-SPym 1.5796 28 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR36## 2-SPym 1.5687 29 OCH.sub.3 ##STR37## 2-SPym 74.about.78 30 OH ##STR38## 2-SPym 170.5.about.174 31 OCH.sub.3 ##STR39## 2-SPym unmeasurable 32 OH ##STR40## 2-SPym 160.about.162 33 OCH.sub.3 ##STR41## 2-SPym 1.5681 34 OH ##STR42## 2-SPym 179.about.182 35 OCH.sub.3 ##STR43## 2-SPym 1.5786 36 OH ##STR44## 2-SPym 173.about.176 37 OCH.sub.3 4-Ph, 5-CH.sub.3 2-SPym 150.about.153 38 OH 4-Ph, 5-CH.sub.3 2-SPym 140.about.143 39 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR45## 2-SPym 1.5409 40 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR46## 2-SPym 1.5641 41 OCH.sub.3 ##STR47## 2-SPym 117.about.120 42 OH ##STR48## 2-SPym 199.5.about.202 43 OCH.sub.3 ##STR49## 2-SPym 107.about.110 44 OH ##STR50## 2-SPym 198.about.201 45 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR51## 2-SPym 1.5659 46 OCH.sub.3 ##STR52## 2-SPym 1.5990 47 OH ##STR53## 2-SPym 182.about.184 48 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR54## 2-SPym 1.5625 49 OCH.sub.3 ##STR55## 2-SPym 118.about.121 50 OH ##STR56## 2-SPym 185.about.187 51 OCH.sub.3 ##STR57## 2-SPym 1.6074 52 OH ##STR58## 2-SPym 187.about.190 53 OCH.sub.3 4-Ph, 5-C.sub.2 H.sub.5 2-SPym 143.5.about.146 54 OH 4-Ph, 5-C.sub.2 H.sub.5 2-SPym 163.about.166.5 55 OH 4-Ph, 5-OCH.sub.3 2-SPym 157.about.162 56 OH ##STR59## 2-SPym 156.5.about.160 57 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR60## 2-SPym 1.5719 58 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR61## 2-SPym 1.5719 59 OH ##STR62## 2-SPym 188.about.192 60 OCH.sub.3 ##STR63## 2-SPym 96.about.100 61 OH ##STR64## 2-SPym 178.about.181 62 OCH.sub.3 ##STR65## 2-SPym 1.5976 63 OH ##STR66## 2-SPym 172.5.about.174.5 64 OCH.sub.3 ##STR67## 2-SPym 146.about.148 65 OH ##STR68## 2-SPym 184.5.about.187 66 OCH.sub.3 ##STR69## 2-SPym 1.6091 67 OH ##STR70## 2-SPym 174.about.176 68 OCH.sub.3 ##STR71## 2-SPym 125.about.127 69 OH ##STR72## 2-SPym 201.about.203.5 70 OCH.sub.3 ##STR73## 2-SPym 1.5907 71 OH ##STR74## 2-SPym 170.about.172 72 OCH.sub.3 ##STR75## 2-SPym 1.5831 73 OH ##STR76## 2-SPym 177.about.179 74 OCH.sub.3 ##STR77## (g) 1.5965 75 OH ##STR78## (g) 172.about.174 76 OCH.sub.3 4-Ph (h) 77 OH 4-Ph (h) 125.about.128 78 OCH.sub.3 4-Ph (g) 79 OH 4-Ph (g) 145.about.150 80 OCH.sub.2 OCOC.sub.4 H.sub.9 4-Ph 2-STri 1.5562 81 OCH.sub.3 OCOC.sub.4 H.sub.9 -t 4-Ph 2-STri unmeasurable 82 OCH.sub.3 4-OPh 2-SPym 83 OH 4-OPh 2-SPym 84 OCH.sub.2 OCOC.sub.4 H.sub.9 -t 4-OPh 2-SPym 85 OCH.sub.3 4-SPh 2-SPym 86 OH 4-SPh 2-SPym 87 OCH.sub.2 OCOC.sub.4 H.sub.9 -t 4-SPh 2-SPym 88 OCH.sub.3 ##STR79## 2-SPym 89 OH ##STR80## 2-SPym 90 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR81## 2-SPym 91 OCH.sub.3 ##STR82## 2-SPym 92 OH ##STR83## 2-SPym 93 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR84## 2-SPym 94 OCH.sub.3 ##STR85## 2-SPym 95 OH ##STR86## 2-SPym 96 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR87## 2-SPym 97 OCH.sub.3 ##STR88## 2-SPym 98 OH ##STR89## 2-SPym 99 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR90## 2-SPym100 OCH.sub.3 ##STR91## 2-SPym101 OH ##STR92## 2-SPym102 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR93## 2-SPym103 OCH.sub.3 ##STR94## 2-SPym104 OH ##STR95## 2-SPym105 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR96## 2-SPym106 OCH.sub.3 ##STR97## 2-SPym107 OH ##STR98## 2-SPym108 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR99## 2-SPym109 OCH.sub.3 ##STR100## 2-SPym110 OH ##STR101## 2-SPym111 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR102## 2-SPym112 OCH.sub.3 ##STR103## 2-SPym113 OH ##STR104## 2-SPym114 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR105## 2-SPym115 OCH.sub.3 ##STR106## 2-SPym116 OH ##STR107## 2-SPym117 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR108## 2-SPym118 OCH.sub.3 ##STR109## 2-SPym119 OH ##STR110## 2-SPym120 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR111## 2-SPym121 OCH.sub.3 ##STR112## 2-SPym122 OH ##STR113## 2-SPym123 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR114## 2-SPym124 OH 4-COCH.sub.3 2-SPym125 OH ##STR115## 2-SPym126 OH ##STR116## 2-SPym127 OH ##STR117## 2-SPym128 OH ##STR118## 2-SPym129 OH ##STR119## 2-SPym130 OH ##STR120## 2-SPym131 OH ##STR121## 2-SPym132 OH 4-NHPH 2-SPym133 OH 4-CH.sub.2Ph 2-SPym134 OH ##STR122## 2-SPym135 OH ##STR123## 2-SPym136 OH ##STR124## 2-SPym137 OH 4-COC.sub.2 H.sub.5 2-SPym138 OH ##STR125## 2-SPym139 OH ##STR126## 2-SPym140 OH 4-CHNOCH.sub.3 2-SPym141 OH ##STR127## 2-SPym142 OH 4-COOH 2-SPym143 OCH.sub.3 4-COOCH.sub.3 2-SPym144 OH 4-COOCH.sub.3 2-SPym145 SCH.sub.3 4-Ph 2-SPym146 H 4-Ph 2-SPym147 OH 2-Ph 2-SPym148 OH ##STR128## 2-SPym149 OH ##STR129## 2-SPym150 OH ##STR130## 2-SPym151 OH ##STR131## 2-SPym152 OH 4-SCH.sub.3 2-SPym153 OH ##STR132## 2-SPym154 OH ##STR133## 2-SPym155 OH ##STR134## 2-SPym156 OH 4-SC.sub.2 H.sub.5 2-SPym157 OH ##STR135## 2-SPym158 OCH.sub.3 4-Ph 2-STri159 OH 4-Ph 2-STri 146.about.147.5160 OC.sub.2 H.sub.5 ##STR136## 2-SPym 89.about.98161 NHSO.sub.2 CH.sub.3 ##STR137## 2-SPym 54.about.58162 ##STR138## ##STR139## 2-SPym 54.about.61163 ##STR140## ##STR141## 2-SPym unmeasurable164 SCH.sub.3 ##STR142## 2-S Pym 131.about.132165 OPh ##STR143## 2-SPym unmeasurable166 SPh ##STR144## 2-SPym167 O.sup.- Na.sup.+ ##STR145## 2-SPym 244.about.247168 ##STR146## ##STR147## 2-SPym169 OCH.sub.3 4-Ph (i)170 OH 4-Ph (i) 137.about.141171 ##STR148## ##STR149## 2-SPym172 OH ##STR150## 2-SPym173 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR151## 2-SPym174 OH ##STR152## 2-SPym 173.about.177175 OCH.sub. 3 ##STR153## 2-SPym 1.5938176 OH ##STR154## 2-SPym 189.about.192177 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR155## 2-SPym178 OH ##STR156## 2-SPym 187.5.about.189179 ##STR157## ##STR158## 2-SPym180 OH ##STR159## 2-SPym181 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR160## 2-SPym182 OH ##STR161## 2-SPym183 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR162## 2-SPym184 OH ##STR163## 2-SPym185 OCH.sub.3 ##STR164## 2-SPym186 OH ##STR165## 2-SPym187 OH ##STR166## 2-SPym188 ##STR167## 4-Ph, 5-Cl 2-SPym189 OH 4-Ph, 5-Cl 2-SPym190 OCH.sub.2 OCOC.sub.4 H.sub.9 -t ##STR168## 2-SPym191 OH ##STR169## 2-SPym192 OCH.sub.2 OCOC.sub.4 H.sub.9 -t 4-Ph, 6-Cl 2-SPym193 OH 4-Ph, 6-Cl 2-SPym194 OCH.sub.2 OCOC.sub.4 H.sub.9 -t 4-Ph, 6-OCH.sub.3 2-SPym195 OH 4-Ph, 6-OCH.sub.3 2-SPym196 ##STR170## ##STR171## 2-SPym197 OH ##STR172## 2-SPym198 OCH.sub.2 OCOC.sub.4 H.sub.9 -t 4-Ph, 6-C.sub.2 H.sub.5 2-SPym199 OH 4-Ph, 6-C.sub.2 H.sub.5 2-SPym200 OH ##STR173## 2-SPym201 OH ##STR174## 2-SPym202 OH ##STR175## 2-SPym203 OH ##STR176## 2-SPym204 OH ##STR177## 2-SPym205 OH ##STR178## 2-SPym206 OH ##STR179## 2-SPym207 OH ##STR180## 2-SPym208 OH ##STR181## 2-SPym209 OH ##STR182## 2-SPym210 OH ##STR183## 2-SPym211 ##STR184## ##STR185## 2-SPym 145.5.about.147212 OH ##STR186## 2-SPym213 OH ##STR187## 2-SPym214 OH ##STR188## 2-SPym215 OH ##STR189## 2-SPym216 OH ##STR190## 2-SPym217 OH ##STR191## 2-SPym218 OH ##STR192## 2-SPym219 OH ##STR193## 2-SPym220 OH ##STR194## 2-SPym221 OH ##STR195## 2-SPym222 OH ##STR196## 2-SPym223 OH ##STR197## 2-SPym224 OH ##STR198## 2-SPym225 OH ##STR199## 2-SPym226 OH ##STR200## 2-SPym227 OH ##STR201## 2-SPym228 OH ##STR202## 2-SPym229 OH ##STR203## 2-SPym230 OCH.sub.3 ##STR204## 2-SPym 1.5901231 OH ##STR205## 2-SPym 135-138232 OH ##STR206## 2-SPym233 O.sup.- N.sup.+ H.sub.3 C.sub.3 H.sub.7 -i ##STR207## 2-SPym 161.about.168234 OH 4-SCH.sub.2Ph 2-SPym 138.about.144235 OH 4-OCHF.sub.2 2-SPym236 OH 4-Ph (m) 202.about.205237 OH 4-OCH.sub.2Ph 2-SPym238 OH 4-OCH.sub.2 CHCH.sub.2 2-SPym239 OH 4-OCH.sub.2 C CH 2-SPym240 OH ##STR208## 2-SPym241 OH 5-Ph 2-SPym242 OH 6-Ph 2-SPym243 OCH.sub.2 OCOPh 4-Ph 2-SPym244 OH 4-NHCOPh 2-SPym245 OCH.sub.3 4-SCH.sub.2Ph 2-SPym 81.about.86__________________________________________________________________________ TABLE 2__________________________________________________________________________ ##STR209## Physical properties Melting point (.degree.C.) orIntermediate No. R.sup.3 R.sup.4 R.sup.5 R.sup.6 Refractive index (n.sub.D.sup.20)__________________________________________________________________________ 1 Ph H H CH.sub.3 144.about.146 2 Ph H H C.sub.2 H.sub.5 3 ##STR210## H H CH.sub.3 4 ##STR211## H H CH.sub.3 5 ##STR212## H H CH.sub.3 175.about.178 6 ##STR213## H H CH.sub.3 164.about.166.5 7 ##STR214## H H CH.sub.3 156.about.159 8 Ph CH.sub.3 H CH.sub.3 9 Ph H CH.sub.3 CH.sub.3 180.about.18410 CH.sub.3 O H H CH.sub.3 125.about.12811 CH.sub.3 H H CH.sub.3 88.about.9312 ##STR215## H H CH.sub.3 121.about.12613 CH.sub.3 NH H H CH.sub.314 ##STR216## H CH.sub.3 CH.sub.315 i-C.sub.3 H.sub.7 H H CH.sub.3 123.about.12616 i-C.sub.3 H.sub.7 H CH.sub.3 CH.sub.317 ##STR217## H H CH.sub.3 136.about.14018 ##STR218## H H CH.sub.3 183.5.about.18819 ##STR219## H H CH.sub.3 198.5.about.200.520 ##STR220## H H CH.sub.3 215.about.217.521 ##STR221## H H CH.sub. 3 157.about.15922 ##STR222## H H CH.sub.3 159.about.16223 ##STR223## H H CH.sub.3 122.about.12624 ##STR224## H H CH.sub.3 205.about.20825 ##STR225## H H CH.sub.3 219.about.22326 ##STR226## H H CH.sub.3 180.about.18427 ##STR227## H H CH.sub.3 148.about.15028 ##STR228## H H CH.sub.329 ##STR229## H H CH.sub.3 147.about.14930 ##STR230## H H CH.sub.3 154.about.15731 ##STR231## H H CH.sub.332 ##STR232## H H CH.sub.333 ##STR233## H H CH.sub.334 ##STR234## H H CH.sub.335 ##STR235## H H CH.sub.336 ##STR236## H H CH.sub.3 149.about.15237 ##STR237## H H CH.sub.3 127.about.13038 ##STR238## H H CH.sub.3 129.about.13139 ##STR239## H H CH.sub.3 232.about.233.540 ##STR240## H H CH.sub.3 184.about.18741 ##STR241## H H CH.sub.342 ##STR242## H H CH.sub. 3 225.about.22743 ##STR243## H H CH.sub.344 ##STR244## H H CH.sub.345 ##STR245## H H CH.sub.3 155.5.about.15746 ##STR246## H H CH.sub.347 PhO H H CH.sub.3 195.about.19848 ##STR247## H H CH.sub.3 183.about.185.549 Ph OCH.sub.3 H CH.sub.3 154.about.15850 ##STR248## H CH.sub.3 CH.sub.3 198.about.20151 ##STR249## H CH.sub.3 CH.sub.3 131.about.13652 ##STR250## H CH.sub.3 CH.sub.3 190.about.192.5__________________________________________________________________________ TABLE 3__________________________________________________________________________ ##STR251## Physical properties Melting point (.degree.C.) orIntermediate No. R.sup.3 R.sup.4 R.sup.5 R.sup.6 L Refractive index (n.sub.D.sup.20)__________________________________________________________________________ 53 Ph H H CH.sub.3 Br 54 Ph H H H Cl 190.about.194 55 Ph H H H Br 181.about.184 56 ##STR252## H H CH.sub.3 Br 73.about.76 57 ##STR253## H H H Br 204.about.208 58 ##STR254## H H H Cl 209.about.212 59 ##STR255## H H CH.sub.3 Br 60 ##STR256## H H H Br 178.about.182 61 ##STR257## H H CH.sub.3 Br 62 ##STR258## H H H Br 183.about.186.5 63 ##STR259## H H CH.sub.3 Cl 64 ##STR260## H H H Cl 195.about.199 65 ##STR261## H H CH.sub.3 Br 66 ##STR262## H H H Br 180.about.182 67 ##STR263## H H CH.sub.3 Br 166.about.169 68 ##STR264## H H H Br 69 ##STR265## H H CH.sub.3 Br 89.about.90.5 70 ##STR266## H H H Br 206.about.209 71 ##STR267## H H CH.sub.3 Br 72 ##STR268## H H H Br 73 ##STR269## H H CH.sub.3 Br 74 ##STR270## H H H Br 75 ##STR271## H H CH.sub.3 Br 79.about.82 76 ##STR272## H H H Br 77 ##STR273## H H CH.sub.3 Br 78 ##STR274## H H H Br 197.about.199.5 79 ##STR275## H H CH.sub.3 Br 71.about.73 80 ##STR276## H H H Br 165.about.168.5 81 ##STR277## H H CH.sub.3 Br 82 ##STR278## H H H Br 215.about.219 83 ##STR279## H H CH.sub.3 Br 85.5.about.87 84 ##STR280## H H H Br 185.about.189 85 ##STR281## H H CH.sub.3 Br 83.about.84.5 86 ##STR282## H H H Br 180.about.184 87 ##STR283## H H CH.sub.3 Br 88 ##STR284## H H H Br 89 ##STR285## H H CH.sub.3 Br 90 ##STR286## H H H Br 91 ##STR287## H H CH.sub.3 Br 92 ##STR288## H H H Br 93 ##STR289## H H CH.sub.3 Br 168.about.173 94 ##STR290## H H H Br 163.about.167 95 ##STR291## H H CH.sub.3 Br 96 ##STR292## H H H Br 97 ##STR293## H H CH.sub.3 Br 73.about.75 98 ##STR294## H H H Br 160.about.163 99 ##STR295## H H CH.sub.3 Br100 ##STR296## H H H Br101 ##STR297## H H H Br 69.about.73102 ##STR298## H H CH.sub.3 Br103 ##STR299## H H CH.sub.3 Br104 ##STR300## H H H Br105 ##STR301## H H CH.sub.3 Br106 ##STR302## H H H Br 173.about.176107 ##STR303## H H CH.sub.3 Br108 ##STR304## H H H Br109 ##STR305## H H CH.sub.3 Br110 ##STR306## H H H Br 193.about.197111 ##STR307## H H CH.sub.3 Br112 ##STR308## H H H Br113 ##STR309## H H CH.sub.3 Br114 ##STR310## H H H Br 188.about.191115 ##STR311## H H CH.sub.3 Br116 ##STR312## H H H Br117 ##STR313## H H CH.sub.3 Br118 ##STR314## H H H Br119 ##STR315## H H CH.sub.3 Br120 ##STR316## H H H Br121 ##STR317## H H CH.sub.3 Br 86.about.89122 ##STR318## H H H Br 172.about.175123 ##STR319## H H CH.sub.3 Br 96.about.98124 ##STR320## H H H Br 198.about.201125 ##STR321## H H CH.sub.3 Br 89.about.92126 ##STR322## H H H Br127 ##STR323## H H CH.sub.3 Br128 ##STR324## H H H Br 208.about.210129 ##STR325## H H CH.sub.3 Br130 ##STR326## H H H Br 174.about.177131 ##STR327## H H CH.sub.3 Br132 ##STR328## H H H Br133 ##STR329## H H CH.sub.3 Br134 ##STR330## H H H Br135 ##STR331## H H CH.sub.3 Br136 ##STR332## H H H Br137 ##STR333## H H CH.sub.3 Br138 ##STR334## H H H Br139 ##STR335## H H CH.sub.3 Br140 ##STR336## H H H Br141 PhO H H CH.sub.3 Br 118.about.120142 PhO H H H Br143 Ph CH.sub.3 H CH.sub.3 Br 129.about.133144 Ph CH.sub.3 H H Br 216.about.218145 ##STR337## H CH.sub.3 CH.sub.3 Br 94.about.97146 ##STR338## H CH.sub.3 H Br 199.about.201147 Ph C.sub.2 H.sub.5 H CH.sub.3 Br 129.about.132148 Ph C.sub.2 H.sub.5 H H Br 173.about.175149 Ph CH.sub.3 O H CH.sub.3 Br150 Ph CH.sub.3 O H H Br 195.about.199151 i-C.sub.3 H.sub.7 H H CH.sub.3 Cl152 i-C.sub.3 H.sub.7 H H H Cl 156.about.158153 Ph H CH.sub.3 CH.sub.3 Br154 Ph H CH.sub.3 H Br155 PhCH.sub.3 S H H H Br 165.about.169__________________________________________________________________________

The herbicidal composition of the present invention comprises at least one of the pyridine derivative of the general formula (I) and its salt as an effective ingredient.

The compound of the present invention can be used as it is as a herbicide, but it may be used in such an appropriate formulation as a dust, a wettable powder, an emulsifiable concentrate, a micro-particle agent or a granule agent by blending with a carrier, a surfactant, a dispersing agent or an adjuvant which may be generally used in the formulation of agricultural chemicals.

As a carrier to be used for these formulations, there may be enumerated a solid carrier such as Jeeklite, talc, bentonite, clay, kaolin, diatomaceous earth, white carbon, vemiculite, calcium carbonate, slaked lime, silica sand, ammonium sulfate or urea, or a liquid carrier such as isopropanol, xylene, cyclohexanone or methyl naphthalene.

As a surfactant and a dispersing agent, there may be enumerated, for example, a metal salt of an alkylbenzenesulfonic acid, a metal salt of a dinaphthylmethanedisulfonic acid, an alcohol-sulfuric acid ester, an alkylaryl sulfonate, a lignin sulfonate, a polyoxyethylene glycol ether, a polyoxyethylene alkyl aryl ether or a polyoxyethylene sorbitol monoalkylate. As an adjuvant, for example, carboxymethyl cellulose, polyethylene glycol or gum arabic may be enumerated.

The dust is prepared by blending the active ingredient with a powdery solid carrier. The wettable powder can be prepared by blending the active ingredient with a powdery solid carrier, a surfactant and a dispersing agent. The emulsifiable concentrate can be prepared by mixing the active ingredient with a liquid carrier, a surfactant and a dispersing agent. The granule agent can be prepared by coating a granular solid carrier with the active ingredient, together with an adjuvant, or by adding water to a solid carrier, the active ingredient and an adjuvant and extruding the mixture through apertures. The proportion of the active ingredient is optionally selected depending on its use, and it is usually from 0.01 to 20% by weight, preferably from 0.1 to 10% by weight, in the cases of dust and granule formulations, and from 0.1 to 80% by weight, preferably from 1 to 50% by weight, in the cases of emulsifiable concentrate and wettable powder formulations.

In practical use, the herbicide of the present invention may be diluted to a suitable concentration before applying or may be directly applied. The amount of the herbicide of the present invention may be optionally varied depending on the type of the compound used, the type of weed to be controlled, growing tendency, environmental conditions and the type of formulation used. When the herbicide of the present invention is directly applied as in the case of powder and granule formulation, it is used at a dose of from 0.1 g to 5 kg, preferably from 1 g to 1 kg of the active ingredient per 10 ares. In the case of liquid application such as emulsifiable concentrate and wettable powder formulations, the active ingredient may optionally be diluted to a concentration of from 0.1 to 10,000 ppm, preferably from 10 to 5,000 ppm for application.

The herbicide of the present invention may be applied to foliage, soil or water surface.

If desired, the compound of the present invention may be used in combination with insecticides, sterilizers, other herbicides, plant growth controlling agents, fertilizers or the like.

Now, typical Formulation Examples for the herbicidal composition of the present invention will be given. The types of compounds and additives and the blending ratios should not be limited thereto, and may optionally be varied in a wide range. In these Examples, "part" means "part by weight".

FORMULATION EXAMPLE 1 (wettable powder)

10 Parts of Compound No. 1, 0.5 part of polyoxyethyleneoctylphenyl ether, 0.5 part of sodium .beta.-naphthalenesulfonate-formalin condensate, 20 parts of diatomaceous earth and 69 parts of clay were mixed and pulverized to obtain a wettable powder.

FORMULATION EXAMPLE 2 (wettable powder)

10 Parts of Compound No. 178, 0.5 part of Polyoxyethyleneoctylphenyl ether, 0.5 part of sodium .beta.-naphthalenesulfonate-formalin condensate, 20 parts of diatomaceous earth, 5 parts of white carbon and 64 parts of clay were mixed and pulverized to obtain a wettable powder.

FORMULATION EXAMPLE 3 (wettable powder containing calcium carbonate)

10 Parts of Compound No. 22, 0.5 part of polyoxyethyleneoctylphenyl ether, 0.5 part of sodium naphthalenesulfonate-formalin condensate, 20 parts of diatomaceous earth, 5 parts of white carbon and 64 parts of calcium carbonate were mixed and pulverized to obtain a wettable powder.

FORMULATION EXAMPLE 4 (emulsifiable concentrate)

30 Parts of Compound No. 9, 60 parts of equivalent amount mixture of xylene and isophorone, and 10 parts of a surfactant mixture of polyoxyethylene sorbitol alkylate, polyoxyethylenealkylaryl polymer and alkylaryl sulfonate were fully stirred to obtain an emulsifiable concentrate.

FORMULATION EXAMPLE 5 (granule)

10 Parts of Compound No. 50, 80 parts of a bulking agent comprising a 1:3 mixture of talc and bentonite, 5 parts of white carbon, 5 parts of a surfactant mixture of polyoxyethylenesorbitol alkylate, polyoxyethylenealkylaryl polymer and alkylarylsulfonate and 10 parts of water were fully kneaded to obtain a paste-like material. The paste-like material was then extruded through a sieve aperture of 0.7 mm in diameter, and the extruded product was dried and cut into pieces of 0.5 to 1 mm in length to obtain granules.

The compound having the general formula (I) and its salt of the present invention are effective at a very small dosage for killing various troublesome weeds grown in upland fields in a wide range from germinating stage to growing stage, examples of the weeds including broadleaf weeds such as pale smartweed (Polygonum lapathifolium), slender amaranth (Amaranthus viridis), common lambsquarters (Chenopodium album), chickweed (Stellaria media), velvet leaf (Abutilon theophrasti), prickly sida (Sida spinosa), morningglory (Ipomoea sp.) and common cocklebur (Xanthum strumarium); perennial and annual cyperaceous weeds such as purple nutsedge (Cyperus rotundus), yellow nutsedge, Cyperus esculetus, umbrella plant (Cyperus microiria) and rice flatsedge (Cyperus iria.); and gramineous weeds such as barnyardgrass (Echinochloa crus-galli), crabgrass (Digitaria sp.), foxtail (Setaria sp.), annual bluegrass (Poa annua), johnsongrass (Sorghum halepense), Alopecurus aequalis and wild oats. Also, the compound of the present invention achieves excellent herbicidal effects on annual weeds such as barnyardgrass (Echinochloa crusqalli), small flower flatsedge (Cyperus difformis) and monochoria (Monochoria vaginalis), and perennial weeds such as Sagittaria pygmaea, Cyperus serotinus, Eleocharis kuroguwai, bulrush (Scirpus hotarui) and Alisma canaliculatum, grown in paddy fields. Depending on the type, the compound of the present invention does not have phytotoxicity to rice, wheat, cotton and corn, and is therefore suitable as a herbicide for cultivating these crops.

Now, the herbicidal effects of the compounds of the present invention will be described with reference to the following Test Examples.

TEST EXAMPLE 1

(Herbicidal effect test by paddy field soil treatment)

In a plastic pot (surface area: 100 cm.sup.2) filled with paddy field soil, barnyardgrass (Ec), monochoria (Mo) and bulrush (Sc) were sown after puddling and leveling, and flooded to a water depth of 3 cm. Next day, a wettable powder prepared in accordance with Formulation Example 1 was diluted with water, and was applied dropwise to the water surface in such manner as to apply 100 g of the active ingredient per 10 ares. The plants were then cultured in a green house, and the evaluation of the herbicidal effect was conducted on the 21st day after the treatment in accordance with the standards as identified in Table 4. The results are shown in the following Table 5.

In the Test Examples, the following compounds were used as Comparative Examples. (Hereinafter, the same in each test.)

Comparative Compound A

methyl 5-chloro-3-(4,6-dimethoxypyrimidin-2-yl)oxypicolinate (see Japanese Unexamined Patent Publication No. 84/1989)

Comparative Compound B

N-[3-(4,6-dimethoxypyrimidin-2yl)]trifluoromethanesulfonamide (see Japanese Unexamined Patent Publication No. 149567/1990)

Comparative Compound C

4-i-propyl-2-(4,6-dimethoxypyrimidin-2-yl)thionicotinic acid (see EP 467139)

Comparative Compound D

methyl 5-chloro-2-(4,6-dimethoxypyrimidin-2-yl)thionicotinate (see EP 467139)

Comparative Compound E

5-chloro-2-(4,6-dimethoxypyrimidin-2-yl)thionicotinic acid (see EP 467139) TABLE 4______________________________________ Herbicidal effects and phytotoxicityIndex No. (growing-controlling degree)______________________________________5 Herbicidal effect: at least 90% Phytotoxicity: at least 90%4 Herbicidal effect: at least 70% and less than 90% Phytotoxicity: at least 70% and less than 90%3 Herbicidal effect: at least 50% and less than 70% Phytotoxicity: at least 50% and less than 70%2 Herbicidal effect: at least 30% and less than 50% Phytotoxicity: at least 30% and less than 50%1 Herbicidal effect: at least 10% and less than 30% Phytotoxicity: at least 10% and less than 30%0 Herbicidal effect: 0 to less than 10% Phytotoxicity: 0 to less than 10%______________________________________ TABLE 5______________________________________Compound Herbicidal effectNo. Ec Mo Sc______________________________________1 5 5 53 5 5 54 5 5 55 5 5 56 5 5 59 5 5 513 5 5 515 5 5 517 5 5 518 5 5 519 5 5 520 5 5 522 5 5 526 5 5 528 5 5 530 5 5 532 5 5 534 5 5 436 5 5 539 5 5 440 5 5 542 5 5 544 5 5 545 5 5 547 5 5 548 5 5 550 5 5 352 5 5 556 5 5 557 5 5 558 5 5 561 5 5 563 5 5 366 5 5 467 5 5 571 5 5 573 5 5 374 4 5 5162 5 5 5167 5 5 5176 5 5 5178 5 5 5211 5 5 5233 5 5 5(A) 2 3 1(B) 4 2 3(C) 0 0 0(D) 0 4 3(E) 0 1 0______________________________________

TEST EXAMPLE 2

(Herbicidal effect test by upland field soil treatment)

In a plastic pot (surface area: 120 cm.sup.2) filled with upland field soil, barnyardgrass (Ec), pale smartweed (Po), slender amaranth (Am), common lambsquarters (Ch) and rice flatsedge (Ci) were sown and covered with soil. A wettable powder prepared in accordance with Formulation Example 1 was diluted with water, and applied uniformly to the soil surface by a small-sized sprayer in an amount of 100 l/10 ares so as to apply 100 g of the active ingredient per 10 ares. The plants were then cultured in a green house, and the evaluation of the herbicidal effect was conducted on the 21th day after the treatment in accordance with the standard as identified in the above Table 4. The results are shown in the following Table 6.

TABLE 6______________________________________Compound Herbicidal effectNo. Ec Po Am Ch Ci______________________________________1 5 5 5 5 53 5 5 5 5 54 5 5 5 5 55 5 5 5 5 56 5 5 5 5 59 5 5 5 5 513 5 5 5 5 515 5 5 5 5 517 5 5 5 5 518 5 5 5 5 519 5 5 5 5 520 3 5 5 5 522 5 5 5 5 524 3 5 4 4 226 5 5 5 5 527 2 5 4 5 428 5 5 5 5 532 4 5 5 5 534 5 5 5 5 536 4 5 5 5 539 4 5 5 3 340 3 5 4 3 342 4 5 5 5 544 5 5 5 5 547 5 5 5 5 548 5 5 5 5 550 4 5 5 5 552 5 5 5 5 555 2 5 5 5 356 4 5 5 5 557 3 5 4 3 458 4 5 5 5 561 5 5 5 5 563 5 5 5 5 565 3 5 5 5 567 4 5 5 5 569 4 3 4 5 371 4 5 5 5 573 5 5 5 5 581 3 4 4 5 2159 2 5 5 5 5167 5 5 5 5 5176 5 5 5 5 5178 5 5 5 5 5211 3 5 5 5 5233 5 5 5 5 5236 3 5 5 5 4(A) 0 0 2 2 4(B) 1 0 0 1 0(D) 0 0 2 1 1______________________________________

TEST EXAMPLE 3

(Herbicidal effect test by upland field foliage treatment)

In a plastic pot (surface area: 120 cm.sup.2) filled with upland field soil, barnyardgrass (Ec), pale smartweed (Po), slender amaranth (Am), common lambsquarters (Ch) and rice flatsedge (Ci) were sown and covered with soil and were cultured in a green house for 2 weeks. A wettable powder prepared in accordance with Formulation Example 1 was diluted with water, and applied onto the foliages by a small-sized sprayer in an amount of 100 l/10 ares so as to apply 100 g of the active ingredient per 10 ares. The plants were then cultured in the green house, and the evaluation of the herbicidal effect was conducted on the 14th day after the treatment in accordance with the standard as identified in the above Table 4. The results are shown in the following Table 7.

TABLE 7______________________________________Compound Herbicidal effectNo. Ec Po Am Ch Ci______________________________________1 5 5 5 5 53 5 5 5 5 54 5 5 5 5 55 5 5 5 5 56 5 5 5 5 59 4 5 5 5 513 5 5 5 4 415 5 5 5 5 517 5 5 5 5 518 5 5 5 4 319 5 5 5 5 520 4 5 5 5 422 5 5 5 5 524 3 5 5 5 326 5 5 5 5 527 3 5 5 5 228 5 5 5 5 430 5 5 5 3 432 4 5 5 4 534 5 5 5 4 436 5 5 5 4 439 4 5 5 4 540 4 5 5 4 342 5 5 5 5 544 5 5 5 5 545 4 5 5 4 547 4 5 5 5 548 4 5 5 5 450 4 5 5 5 352 5 5 5 5 555 3 5 5 5 256 4 5 5 4 457 3 5 5 4 358 4 5 5 4 461 4 5 5 5 563 4 5 5 5 364 4 5 5 5 465 5 5 5 5 567 4 5 5 5 569 4 5 5 4 471 5 5 5 5 573 5 5 5 5 581 5 5 4 4 3159 5 5 5 5 3162 4 5 5 4 2163 4 3 4 4 1167 5 5 5 5 5174 5 5 5 4 5176 5 5 5 5 5178 5 5 5 5 5364 3 5 5 4 3233 5 5 5 5 5236 3 5 5 3 4(A) 0 1 2 2 3(B) 0 0 0 1 3(D) 0 3 3 2 0(E) 0 3 3 3 3______________________________________

TEST EXAMPLE 4

(Herbicidal effect test and phytotoxicity test to rice by upland field foliage treatment)

In a plastic pot (surface area: 600 cm.sup.2) filled with upland field soil, rice (Or), johnsongrass (So), Alopecurus aequalis (Al), pale smartweed (Po), slender amaranth (Am) and common lambsquarters (Ch) were sown and covered with soil, and were cultured in a green house for 2 weeks. A predetermined amount of a wettable powder prepared in accordance with Formulation Example 1 was diluted with 100 l of water per 10 ares, and was applied onto the foliages by a small-sized sprayer. The plants were then cultured in the green house, and the evaluation of the herbicidal effect and the phytotoxicity was conducted on the 14th day after the treatment in accordance with the standard as identified in the above Table 4. The results are shown in the following Table 8. The dose of active ingredient in the Table shows the amount of the active ingredient (g) per 10 ares.

TABLE 8______________________________________ Dose of Phytoto-Compound active xicity Herbicidal effectNo. ingredient Or So Al Po Am Ch______________________________________6 1.6 1 4 5 5 5 422 6.3 1 4 4 4 5 426 6.3 1 5 5 5 5 428 6.3 0 5 5 5 5 442 1.6 1 5 5 5 5 447 1.6 1 4 4 5 5 448 6.3 1 5 5 5 5 550 6.3 0 4 3 4 4 452 1.6 0 5 3 5 5 455 25.0 1 4 4 5 5 556 1.6 1 4 5 5 5 463 6.3 0 4 5 5 5 367 6.3 0 4 5 5 5 471 6.3 1 5 5 5 5 473 1.6 0 5 5 5 5 4233 1.6 1 3 5 3 5 5(A) 25.0 0 0 0 0 0 0(B) 25.0 0 0 0 0 0 0(C) 25.0 2 0 0 3 4 3(D) 400.0 2 0 0 2 2 2(E) 400.0 2 1 2 3 3 3______________________________________

TEST EXAMPLE 5

(Herbicidal effect test and phytotoxicity test to rice by upland field soil treatment)

In a plastic pot (surface area: 600 cm.sup.2) filled with upland field soil, rice (Or), johnsongrass (So), Alopecurus aequalis (Al), pale smartweed (Po), slender amaranth (Am) and common lambsquarters (Ch) were sown and covered with soil. After absorbing water from the bottom of the pot, a predetermined amount of a wettable powder prepared in accordance with Formulation Example 1 was diluted with 100 l of water per 10 ares, and was applied onto the soil surface by a small-sized sprayer. The plants were then cultured again in a green house, and the evaluation of the herbicidal effect and the phytotoxicity was conducted on the 20th day after the treatment in accordance with the standard as identified in the above Table 4. The results are shown in the following Table 9. The dose of active ingredient in the Table shows the amount of the active ingredient (g) per 10 ares.

TABLE 9______________________________________ Dose of Phytoto-Compound active xicity Herbicidal effectNo. ingredient Or So Al Po Am Ch______________________________________1 1.6 0 4 5 5 5 53 1.6 0 5 4 5 5 34 1.6 1 5 5 5 5 35 1.6 0 5 3 4 5 39 6.3 0 5 5 5 5 517 6.3 0 4 4 5 5 445 6.3 1 5 3 5 5 448 1.6 0 5 3 5 5 550 1.6 0 4 4 3 5 552 1.6 1 2 5 4 5 455 25.0 1 3 3 5 5 561 1.6 0 4 4 4 5 4167 6.3 0 5 5 5 5 5178 6.3 0 5 5 5 5 5233 1.6 0 4 5 5 5 3(A) 25.0 0 0 0 0 0 0(B) 25.0 0 0 0 0 0 0(C) 25.0 2 0 0 5 5 5(D) 400.0 2 0 0 2 4 2(E) 400.0 3 0 0 3 5 3______________________________________

TEST EXAMPLE 6

(Herbicidal effect test and phytotoxicity test to wheat by upland field foliage treatment)

In a plastic pot (surface area: 600 cm.sup.2) filled with upland field soil, wheat (Tr), johnsongrass (So), Alopecurus aequalis (Al), pale smartweed (Po), slender amaranth (Am) and common lambsquarters (Ch) were sown and covered with soil, and were cultured in a green house for 2 weeks. A predetermined amount of a wettable powder prepared in accordance with Formulation Example 1 was diluted with 100 l of water per 10 ares, and was applied onto the foliages by a small-sized sprayer. The plants were then cultured again in a green house, and the evaluation of the herbicidal effect and the phytotoxicity was conducted on the 14th day after the treatment in accordance with the standard as identified in the above Table 4. The results are shown in the following Table 10. The dose of active ingredient in the Table shows the amount of the active ingredient (g) per 10 ares.

TABLE 10______________________________________ Dose of Phytoto-Compound active xicity Herbicidal effectNo. ingredient Tr So Al Po Am Ch______________________________________6 6.3 0 5 5 5 5 49 6.3 0 5 5 5 5 517 1.6 1 5 5 5 5 422 25.0 0 4 4 5 5 526 6.3 0 5 5 5 5 428 6.3 0 5 5 5 5 442 1.6 1 5 5 5 5 444 6.3 1 5 5 5 5 547 6.3 1 5 5 5 5 548 6.3 1 5 5 5 5 550 6.3 0 4 3 4 4 452 1.6 0 5 3 5 5 456 25.0 1 5 5 5 4 463 6.3 1 4 5 5 5 367 6.3 0 4 5 5 5 471 1.6 0 4 5 5 5 473 1.6 1 5 5 5 5 4233 6.3 0 4 5 5 5 5(A) 25.0 0 0 0 0 0 0(B) 25.0 0 0 0 0 0 0(C) 25.0 2 0 0 3 4 3(D) 400.0 2 0 0 2 2 2(E) 400.0 2 1 2 3 3 3______________________________________

TEST EXAMPLE 7

(Herbicidal effect test and phytotoxicity test to wheat by upland field soil treatment)

In a plastic pot (surface area: 600 cm.sup.2) filled with upland field soil, wheat (Tr), johnsongrass (So), Alopecurus aequalis (Al), pale smartweed (Po), slender amaranth (Am) and common lambsquarters (Ch) were sown and covered with soil. After absorbing water from the bottom of the pot, a predetermined amount of a wettable powder prepared in accordance with Formulation Example 1 was diluted with 100 l of water per 10 ares, and was applied onto the soil surface by a small-sized sprayer. The plants were then cultured again in a green house, and the evaluation of the herbicidal effect and the phytotoxicity was conducted on the 20th day after the treatment in accordance with the standard as identified in the above Table 4. The results are shown in the following Table 11. The dose of active ingredient in the Table shows the amount of the active ingredient (g) per 10 ares.

TABLE 11______________________________________ Dose of Phytoto-Compound active xicity Herbicidal effectNo. ingredient Tr So Al Po Am Ch______________________________________1 1.6 0 4 5 5 5 53 1.6 0 5 4 5 5 34 1.6 0 5 5 5 5 35 1.6 0 5 5 5 5 39 6.3 0 5 5 5 5 517 6.3 1 4 4 5 5 422 6.3 1 5 5 4 5 528 25.0 1 5 5 5 5 542 6.3 0 5 5 5 5 544 1.6 0 5 5 5 5 545 6.3 0 5 3 5 5 447 1.6 0 5 3 5 5 548 6.3 1 5 5 5 5 550 6.3 0 5 5 5 5 555 25.0 1 3 3 5 5 556 25.0 1 5 5 5 5 3167 6.3 0 5 5 5 5 5178 6.3 0 5 5 5 5 5233 6.3 0 4 5 5 5 3(A) 25.0 0 0 0 0 0 0(B) 25.0 0 0 0 0 0 0(C) 25.0 3 0 0 5 5 5(D) 400.0 2 0 0 2 4 2(E) 400.0 2 0 0 3 5 3______________________________________

TEST EXAMPLE 8

(Herbicidal effect test and phytotoxicity test to the cotton by upland field foliage treatment)

In a plastic pot (surface area: 600 cm.sup.2) filled with upland field soil, cotton (Go), johnsongrass (So), Alopecurus aequalis (Al), pale smartweed (Po), slender amaranth (Am) and common lambsquarters (Ch) were sown and covered with soil, and were cultured in a green house for 2 weeks. A predetermined amount of a wettable powder prepared in accordance with Formulation Example 1 was diluted with 100 l of water per 10 ares, and was applied onto the foliage by a small-sized sprayer. The plants were then cultured in the green house, and the evaluation of the herbicidal effect and the phytotoxicity was conducted on the 14th day after the treatment in accordance with the standard as identified in the above Table 4. The results are shown in the following Table 12. The dose of active ingredient in the Table shows the amount of the active ingredient (g) per 10 ares.

TABLE 12______________________________________ Dose of Phytoto-Compound active xicity Herbicidal effectNo. ingredient Go So Al Po Am Ch______________________________________17 1.6 1 5 5 5 5 455 25.0 1 4 4 5 5 5(A) 100.0 2 0 0 2 3(B) 400.0 2 0 0 0 2 1______________________________________

TEST EXAMPLE 9

(Herbicidal effect test and phytotoxicity test to cotton by upland field soil treatment)

In a plastic pot (surface area: 600 cm.sup.2) filled with upland field soil, cotton (Go), johnsongrass (So), Alopecurus aequalis (Al), pale smartweed (Po), slender amaranth (Am) and common lambsquarters (Ch) were sown and covered with soil. After absorbing water from the bottom of the pot, a predetermined amount of a wettable powder prepared in accordance with Formulation Example 1 was diluted with 100 l of water per 10 ares, and was applied onto the soil surface by a small-sized sprayer. The plants were then cultured again in a green house, and the evaluation of the herbicidal effect and the phytotoxicity was conducted on the 20th day after the treatment in accordance with the standard as identified in the above Table 4. The results are shown in the following Table 13. The dose of active ingredient in the Table shows the amount of the active ingredient (g) per 10 ares.

TABLE 13______________________________________ Dose of Phytoto-Compound active xicity Herbicidal effectNo. ingredient Go So Al Po Am Ch______________________________________1 1.6 0 4 5 5 5 53 1.6 1 5 4 5 5 34 1.6 1 5 5 5 5 35 1.6 1 5 3 4 5 39 1.6 0 4 5 4 5 419 6.3 1 3 5 5 5 528 25.0 1 5 5 5 5 544 1.6 0 5 5 5 5 548 1.6 1 5 3 5 5 550 1.6 0 4 4 3 5 552 1.6 0 2 5 4 5 455 25.0 0 3 3 5 5 561 1.6 0 4 4 4 5 4167 6.3 0 5 5 5 5 5178 1.6 1 4 4 5 5 4233 1.6 1 4 5 5 5 3(A) 400.0 2 0 0 1 4 2(B) 400.0 2 1 0 0 3 2(C) 25.00 2 0 0 5 5 5(D) 400.0 3 0 0 2 4 2(E) 400.0 2 0 0 3 5 3______________________________________

Claims

1. A compound having the following formula or a herbicidally acceptable salt thereof: ##STR339## wherein R is selected from the group consisting of a hydrogen atom, a hydroxyl group, a C.sub.1 .about.C.sub.7 alkoxy group, a C.sub.1 .about.C.sub.7 alkoxy group, a pivaloyloxymethoxy group, a benzyloxy group, a benzyloxy group substituted with a chlorine atom or a methoxy group, a trimethylsilylethoxy group, a methylsulfonylamino group, a methylthio group, a phenoxy group and a phenylthio group;

R.sup.1 and R.sup.2 are the same or different, and are selected from the group consisting of a hydrogen atom, a C.sub.1 .about.C.sub.7 alkoxy group, a halogen atom, a C.sub.1 .about.C.sub.3 alkylamino group, a di C.sub.1 .about.C.sub.3 alkylamino group, a halo C.sub.1 .about.C.sub.7 alkoxy group and a C.sub.1 .about.C.sub.7 alkyl group;

Z is a methine group;

X.sup.1 is selected from the group consisting of a benzoylamino group, a cyclo C.sub.3 .about.C.sub.7 alkyl group, halo C.sub.1 .about.C.sub.7 alkoxy group, a C.sub.2 .about.C.sub.8 alkenyloxy group, a C.sub.2 .about.C.sub.8 alkynyloxy group, a methoxycarbonyl group, a C.sub.1 .about.C.sub.3 alkylamino group, a di C.sub.1 .about.C.sub.3 alkylamino group, a phenyl group, a phenyl group substituted with substituent selected from the group consisting of a lower alkyl group, a halogen atom, a nitro group, a halo C.sub.1 .about.C.sub.7 alkyl group, a halo C.sub.1 .about.C.sub.7 alkoxy group, a C.sub.1 .about.C.sub.7 alkoxy group, a piperidino group, a di C.sub.1 .about.C.sub.3 alkylamino group, a phenoxy group, a methylphenoxy group, a an ethoxymethoxy group, a methoxyethoxy group, a methoxymethoxy group, a cyano group, an ethynyl group, a C.sub.1 .about.C.sub.3 alkylamino group, a ethoxycarbonyl C.sub.1 .about.C.sub.2 alkoxy group, a methoxymethyl group, a C.sub.1 .about.C.sub.2 alkylthio C.sub.1 .about.C.sub.2 alkoxy group, a benzyloxy group and a hydroxyl group; a benzyl group; a benzyl group substituted with a chlorine atom, a benzyloxy group, and a benzylthio group; a phenoxy group; a phenoxy group substituted with a substituent selected from the group consisting of a halogen atom, a methyl group and a methoxy group; a phenylthio group; a phenylthio group substituted with a substituent selected from the group consisting of a chlorine atom, a methyl group and a methoxy group; a C.sub.1 .about.C.sub.2 alkoxyimino C.sub.1 .about.C.sub.2 alkyl group, a C.sub.2 .about.C.sub.3 acyl group, a C.sub.1 .about.C.sub.2 alkylthio group, a phenylamino group; a phenylamino group substituted with a chlorine atom; a carboxyl group, and a group having the formula, ##STR340## X.sup.2 is selected from the group consisting of a hydrogen atom, halogen atom, a C.sub.1 .about.C.sub.2 alkyl group, a methoxy group, and a di methylamino group.

2. The compound or salt according to claim 1, wherein R is selected from the group consisting of a hydrogen atom, a hydroxyl group, a C.sub.1 .about.C.sub.7 alkoxy group, a benzyloxy group, a benzyloxy group substituted with a chlorine atom or a methoxy group; a methylsulfonylamino group, a methylthio group, and a phenylthio group;

R.sup.1 and R.sup.2 are the same or different, and are selected from the group consisting of a hydrogen atom, a C.sub.1 .about.C.sub.7 alkoxy group, a halogen atom, a halo C.sub.1 .about.C.sub.7 alkoxy group, and a C.sub.1 .about.C.sub.7 alkyl group;

Z is a methine group;

X.sup.1 is selected from the group consisting of a benzoylamino group, a cyclo C.sub.3 .about.C.sub.7 alkyl group, halo C.sub.1 .about.C.sub.7 alkoxy group, a C.sub.2 .about.C.sub.8 alkenyloxy group, a C.sub.2 .about.C.sub.8 alkynyloxy group, a methoxycarbonyl group, a phenyl group, a phenyl group substituted with a substituent selected from the group consisting of a lower alkyl group, a halogen atom, a nitro group, a halo C.sub.1 .about.C.sub.7 alkyl group, a halo C.sub.1 .about.C.sub.7 alkoxy group, a C.sub.1 .about.C.sub.7 alkoxy group, a piperidino group, a di C.sub.1 .about.C.sub.3 alkylamino group, a phenoxy group, a methylphenoxy group, an ethoxymethoxy group, a methoxymethoxy group, a methoxyethoxy group, a cyano group, an ethynyl group, a C.sub.1 .about.C.sub.3 alkylamino group, a ethoxycarbonyl C.sub.1 .about.C.sub.2 alkoxy group, a methoxymethyl group, a C.sub.1 .about.C.sub.2 alkylthio C.sub.1 .about.C.sub.2 alkoxy group, a benzyloxy group and a hydroxyl group; a benzyl group, a benzyloxy group, a benzylthio group, a benzyl group which is substituted with a chlorine atom; a phenoxy group; a phenoxy group substituted with a substituent selected from the group consisting of a halogen atom, a methyl group and a methoxy group; a phenylthio group; a phenylthio group substituted with a substituent selected from the group consisting of a chlorine atom, a methyl group and a methoxy group; a C.sub.1 .about.C.sub.2 alkoxyimino C.sub.1 .about.C.sub.2 alkyl group, a C.sub.2 .about.C.sub.3 acyl group, a C.sub.1 .about.C.sub.2 alkylthio group, a phenylamino group; a phenylamino group substituted with a chlorine atom; a carboxyl group, a benzoylamino group and a 4,6 di methoxypyrimidinylthio group;

X.sup.2 is selected from the group consisting of a hydrogen atom, a chlorine atom, a C.sub.1 .about.C.sub.2 alkyl group, a methoxy group and a di methylamino group.

3. The compound or salt according to claim 1, wherein X.sup.1 is selected from the group consisting of a cyclo C.sub.3 .about.C.sub.7 alkyl group, a halo C.sub.1 .about.C.sub.7 alkoxy group, a C.sub.2 .about.C.sub.8 alkynyloxy group, a methoxycarbonyl group, a phenyl group, a phenyl group substituted with subsitutent selected from the group consisting of a lower alkyl group, a halogen atom, a nitro group, a halo C.sub.1 .about.C.sub.7 alkyl group, a halo C.sub.1 .about.C.sub.7 alkoxy group, a C.sub.1 .about.C.sub.7 alkoxy group, a piperidino group, a di C.sub.1 .about.C.sub.3 alkylamino group, a phenoxy group, a methylphenoxy group, a methoxyethoxy group, a methoxymethoxy group, an ethoxymethoxy group a cyano group, a an ethynyl group, a C.sub.1 .about.C.sub.3 alkylamino group, a ethoxycarbonyl C.sub.1 .about.C.sub.2 alkoxy group, a methoxymethyl group, a C.sub.1 .about.C.sub.2 alkylthio C.sub.1 .about.C.sub.2 alkoxy group, a benzyloxy group and a hydroxyl group; a benzyloxy group, a benzylthio group, a benzyl group; a benzyl group substituted with a chlorine atom; a phenoxy group; a phenoxy group substituted with a substituent selected from the group consisting of a halogen atom, a methyl group and a methoxy group; a phenylthio group; a phenylthio group substituted with a substituent selected from the group consisting of a chlorine atom, a methyl group and a methoxy group; a C.sub.1 .about.C.sub.2 alkoxyimino C.sub.1 .about.C.sub.2 alkyl group, a C.sub.2 .about.C.sub.3 acyl group, a C.sub.1 .about.C.sub.2 alkylthio group, a phenylamino group, a phenylamino group substituted with a chlorine atom, a carboxyl group, a benzoylamino group and a group having the formula, ##STR341## X.sup.2 is selected from the group consisting of a hydrogen atom, a chlorine atom, a C.sub.1 .about.C.sub.2 alkyl group, a methoxy group and a di methylamino group.

4. A compound having the following formula or a herbicidally acceptable salt thereof: ##STR342## wherein R is selected from the group consisting of a hydrogen atom, a hydroxyl group, a C.sub.1 .about.C.sub.7 alkoxy group, a C.sub.1 .about.C.sub.7 alkoxy C.sub.1 .about.C.sub.7 alkoxy group, a pivaloylmethoxy group, a benzyloxy group, a benzyloxy group substituted with a substituent selected from the group consisting of a chlorine atom or a methoxy group; a trimethylsilylethoxy group, a methylsulfonylamino group, a C.sub.1 .about.C.sub.2 alkylthio group, a phenoxy group and a phenylthio group;

R.sup.1 and R.sup.2 are the same or different, and are selected from the group consisting of a hydrogen atom, a C.sub.1 .about.C.sub.7 alkoxy group, a halogen atom, a C.sub.1 .about.C.sub.3 alkylamino group, a di C.sub.1 .about.C.sub.3 alkylamino group, a halo C.sub.1 .about.C.sub.7 alkoxy group and a C.sub.1 .about.C.sub.7 alkyl group;

Z is a methine group;

X.sup.3 is selected from the group consisting of a halogen atom, a C.sub.1 .about.C.sub.7 alkyl group, a C.sub.1 .about.C.sub.7 alkoxy group, a C.sub.1 .about.C.sub.3 alkylamino group, a di C.sub.1 .about.C.sub.3 alkylamino group, a halo C.sub.1 .about.C.sub.7 alkyl group, a halo C.sub.1 .about.C.sub.7 alkoxy group, a nitro group, a hydroxyl group, a di C.sub.1 .about.C.sub.7 alkoxy group, a methoxycarbonyl C.sub.1 .about.C.sub.2 alkoxy group, a C.sub.1 .about.C.sub.2 alkylthio C.sub.1 .about.C.sub.2 alkoxy group, a benzyloxy group, a cyano group, a phenoxy group, a C.sub.1 .about.C.sub.2 alkylthio group, a methoxymethyl group, a C.sub.2 .about.C.sub.8 alkenyl group and a C.sub.2 .about.C.sub.8 alkynyl group;

X.sup.2 is selected from the group consisting of a hydrogen atom, a halogen atom, a C.sub.1 .about.C.sub.2 alkyl group, a methoxy group, and a di methylamino group;

and n is 0 or an integer of 1 to 3, and X.sup.3 can be a combination of different groups when n is at least 2.

5. The compound or salt according to claim 4, wherein X.sup.2 is selected from the group consisting of a hydrogen atom, a C.sub.1 .about.C.sub.2 alkyl group, a methoxy group, a halogen atom, a methylamino group, and a di methylamino group.

6. A compound having the following formula or a herbicidally acceptable salt thereof: ##STR343## wherein R is selected from the group consisting of a hydroxyl group, a C.sub.1 .about.C.sub.7 alkoxy group, a di C.sub.1 .about.C.sub.7 alkoxy group, a pivaloyloxymethyl group, a benzyloxy group, a benzyloxy group substituted with a chlorine atom or a methoxy group; a trimethylsilylethoxy group, a methylsulfonylamino group, a C.sub.1 .about.C.sub.2 alkylthio group and a phenoxy group;

Z is a methine group;

X.sup.3 is selected from the group consisting of a halogen atom, a C.sub.1 .about.C.sub.7 alkyl group, a C.sub.1 .about.C.sub.7 alkoxy group, a C.sub.1 .about.C.sub.3 alkylamino group, a di C.sub.1 .about.C.sub.3 alkylamino group, a halo C.sub.1 .about.C.sub.7 alkyl group, a halo C.sub.1 .about.C.sub.7 alkoxy group, a nitro group, a hydroxyl group, a C.sub.1 .about.C.sub.7 alkoxy C.sub.1 .about.C.sub.7 alkoxy group, a methoxycarbonyl C.sub.1 .about.C.sub.2 alkoxy group, a C.sub.1 .about.C.sub.2 alkylthio C.sub.1 .about.C.sub.2 alkoxy group, a benzyloxy group, a cyano group, a phenoxy group, a C.sub.1 .about.C.sub.2 alkylthio group, a methoxymethyl group, a C.sub.2 .about.C.sub.8 alkenyl group and a C.sub.2 .about.C.sub.8 alkynyl group;

n is 0 or an integer of 1 to 3, and X.sup.3 can be a combination of different groups when n is at least 2.

7. An herbicidal composition comprising a herbicidally effective amount of the compound or a salt thereof as defined in claim 1 and an agriculturally acceptable adjuvant.

8. A method for killing weeds which comprises applying an herbicidally effective amount of the compound or a salt thereof as defined in claim 1 to a locus to be protected.

9. 4-(4-chlorophenyl)-2-(4,6-dimethoxypyrimidin-2-yl thio)nicotinic acid.