Process for the preparation of 1-4-disubstituted-5 (4H)-tetrazolinones

Abstract

1,4-Disubstituted-5(4H)-tetrazolinones of the formula (I) ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 have the meanings given in the specification), which are known to be useful as herbicides, can be obtained in very good yields by reacting the corresponding 1-substituted-5(4H)-tetrazolinones with the corresponding carbamoyl chlorides in the presence of 4-dimethylaminopyridine.

Description

The present invention relates to a novel process for the production of known 1,4-disubstituted-5(4H)-tetrazolinones which can be utilized, for example, as agricultural chemicals.

Regarding the synthesis of tetrazolinones of the type of general formula (I) below, U.S. Pat. No. 4,618,365 discloses a process wherein a tetrazolinone of the general formula: ##STR2## wherein M represents hydrogen or an alkali metal such as Li, Na or K is reacted with a carbomyl chloride.

Concerning the above-mentioned reaction, when use is made, as M, of a hydrogen atom, it is preferably carried out in the presence of a suitable acid-acceptor such as pyridine, a trialkylamine, or the like. Further, in this reaction, use may be made, as suitable solvents, of acetone, acetonitrile, toluene, chloroform, and the like.

However, such known process produces, in addition to the desired tetrazolinones, the isomeric compounds of the general formula (A): ##STR3## (hereinafter referred to as "O-carbamoyl compounds") as by-products and the production rate of such by-products sometimes turns out to be as much as one third of the production rate of the desired compounds (FIGS. 1 to 5).

The O-carbamoyl compound by-products do not exhibit herbicidal activity as comparable to the desired N-carbamoyl tetrazolinones. Further, such O-carbamoyl compounds are chemically unstable, i.e. they are readily hydrolyzable by aqueous acids and alkali so that the separation and removal of O-carbamoyl compounds from the desired N-carbamoyl products (I) is difficult.

Thus the known process has serious inherent defects, viz. with regard to reaction procedure and reaction efficiency.

To solve the above-mentioned technical problem, there has now been found a process--with two process variants (a) and (b)--for selectively producing 1,4-disubstituted-5(4H)-tetrazolinones of the general formula (I), ##STR4## wherein R.sup.1 represents optionally substituted C.sub.1-12 alkyl, optionally substituted C.sub.3-8 cycloalkyl, optionally substituted C.sub.3-8 alkenyl, optionally substituted C.sub.3-8 alkynyl, or a group of the general formula ##STR5## wherein Ar represents optionally substituted phenyl, optionally substituted naphthyl or an optionally substituted five- to seven-membered heterocyclic ring,

R.sup.4 represents hydrogen or C.sub.1-4 alkyl, and n is 0, 1, 2, 3 or 4, R.sup.2 and R.sup.3 each represents, independently, C.sub.1-8 alkyl, C.sub.1-6 haloalkyl, C.sub.2-6 alkoxyalkyl, C.sub.2-6 alkylthioalkyl, C.sub.2-6 alkenyl, C.sub.2-6 haloalkenyl, C.sub.3-6 alkynyl, C.sub.1-4 alkoxy, C.sub.1-4 haloalkoxy, C.sub.3-8 cycloalkyl, optionally substituted phenyl or optionally substituted aralkyl, or R.sup.2 and R.sup.3 together with the adjacent N atom may form a ring, which process comprises (a) reacting a compound of the general formula (II), ##STR6## wherein R.sup.1 has the same meaning as mentioned above, with a compound of the general formula (III) ##STR7## wherein R.sup.2 and R.sup.3 have the same meaning as mentioned above, in the presence of 4-dimethylamino-pyridine and optionally in the presence of a diluent and of an additional acid-binder, or (b) reacting a compound of the above-mentioned general formula (II) with a compound of the above-mentioned general formula (III), optionally in the presence of a diluent and of an acid-binder other than 4-dimethylamino-pyridine, to obtain a mixture consisting of a tetrazolinone of the above-mentioned general formula (I) and a compound of the general formula (IV), ##STR8## wherein R.sup.1, R.sup.2 and R.sup.3 have the same meanings as mentioned above, (first step), followed by reacting said obtained mixture with 4-dimethyl-amino-pyridine, optionally in the presence of a diluent, thereby effecting conversion of the compound(s) of formula (IV) to the desired isomeric compound(s) of the formula (I) by a "carbamoyl-migration" (i.e. 1,3-shift of the carbamoyl group, from O to N) (second step).

The process according to the present invention has surprisingly been found to be able selectively to prepare the desired tetrazolinones of general formula (I) in high yield, either by reacting a compound of general formula (II) with a compound of general formula (III) in the presence of 4-dimethylamino-pyridine (that has not been employed in the prior art processes), or by reacting the above-mentioned starting materials (II) and (III) according to a conventional procedure, followed by reacting the resulting mixture of isomeric compounds of formulas (I) and (IV) with 4-dimethylamino-pyridine, thereby effecting a 1,3-migration of the carbamoyl substituent.

The 4-dimethylamino-pyridine to be employed in the process according to the present invention can be used as acid-acceptor and catalyst, or as catalyst together with another acid-acceptor, as discussed hereinbelow.

The process according to the present invention can be utilized for the prepartion of the many tetrazolinones of general formula (I) and has been found to be most suitable for their production on an industrial scale.

A preferred group of 1,4-disubstituted-5(4H)-tetrazolinones, to be produced according to the present invention, are those compounds of formula (I), wherein

R.sup.1 represents C.sub.1-12 alkyl, C.sub.1-6 haloalkyl, C.sub.2-8 alkoxyalkyl, C.sub.2-8 alkylthioalkyl, C.sub.3-8 cycloalkyl, C.sub.3-8 alkenyl, C.sub.3-8 haloalkenyl, C.sub.3-8 alkynyl, or a group of the general formula ##STR9## wherein Ar represents unsubstituted phenyl, or a phenyl group having a substituent or substituents optionally selected from the group consisting of halogen, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4 alkoxy, C.sub.1-4 haloalkoxy, C.sub.1-4 alkylthio, C.sub.1-4 haloalkylthio, C.sub.1-4 alkoxy-carbonyl, carboxy, optionally substituted phenoxy, optionally substituted heterocyclyl-oxy, methylene dioxy, halomethylene dioxy, ethylene dioxy, haloethylene dioxy, cyano, nitro and --NR.sup.5 R.sup.6 ; or Ar represents unsubstituted naphthyl, or a substituted naphthyl group having a substituent or substituents optionally selected from the group consisting of halogen, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4 alkoxy, C.sub.1-4 4 haloalkoxy, C.sub.1-4 alkylthio, C.sub.1-4 haloalkylthio, C.sub.1-4 alkoxy-carbonyl, carboxyl, optionally substituted phenoxy, optionally substituted heterocyclyl-oxy, methylene dioxy, halomethylene dioxy, ethylene dioxy, haloethylene dioxy, cyano, nitro and --NR.sup.5 R.sup.6 ; or Ar represents a five- to seven-membered heterocyclic ring or their benzologues or their substituted derivatives having a substituent or substituents optionally selected from the group consisting of halogen, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4 alkoxy, C.sub.1-4 haloalkoxy, C.sub.1-4 alkylthio, C.sub.1-4 haloalkylthio C.sub.1-4 alkoxy-carbonyl, carboxy, optionally substituted phenoxy, optionally substituted heterocyclyl-oxy, methylene dioxy, halomethylene dioxy, ethylene dioxy, haloethylene dioxy, cyano, nitro and --NR.sup.5 R.sup.6 ; R.sup.4 represents hydrogen or C.sub.1-4 alkyl, R.sup.5 and R6 may be the same or different and represent hydrogen or C.sub.1-4 alkyl, and n is 0, 1, 2 or 3; and R.sup.2 and R.sup.3 each independently represents methyl, ethyl, n-propyl, isopropyl, n-(sec-,iso-, or tert-)butyl, n-pentyl, n-hexyl, trifluoromethyl, difluoromethyl, 2-chloroethyl, 2-fluoroethyl, 2,2,2-trifluoroethyl, 3-fluoropropyl, perfluoropropyl, perfluorohexyl, 2-methoxyethyl, ethoxymethyl, 2-ethoxyethyl, 2-propoxyethyl, 2-methylthioethyl, 3-methylthiopropyl, 2-ethylthioethyl, allyl, 2-(3-, 4-)butenyl, hexenyl, 3-chloroallyl, propargyl, methoxy, ethoxy, n-propoxy, isopropoxy, 3-chloroallyloxy, cyclopropyl, cyclopentyl, cyclohexyl, optionally substituted phenyl or benzyl, (wherein said substituents may be optionally selected from the group consisting of fluorine, chlorine, bromine, methyl, ethyl, n-propyl, isopropyl, tert-butyl, trifluoromethyl, methoxy, ethoxy, isopropoxy, difluoromethoxy, trifluoromethoxy, methylthio, ethoxy, isopropoxy, difluoromethoxy, trifluoromethoxy, methylthio, ethylthio, trifluoromethylthio, 2,2,2-trifluoroethylthio, cyano and nitro), or R.sup.2 and R.sup.3 together with the adjacent nitrogen atom may form piperidino, 2,6-dimethylpiperidino, morpholino, 2,6-dimethylmorpholino, thiomorpholino, 2,3-dihydroindolyl or perhydroindolyl.

A particularly preferred group of 1,4-disubstituted-5(4H)-tetrazolinones, to be produced according to the present invention, are those compounds of formula (I), wherein

R.sup.1 represents methyl, ethyl, n-propyl, isopropyl, n-(sec-, iso-, or tert-)butyl, n-hexyl, trifluoromethyl, difluoromethyl, chlorodifluoromethyl, 2,2,2-trifluoroethyl, perfluoropropyl, perfluorohexyl, methoxyethyl, ethoxymethyl, ethoxyethyl, propoxyethyl, butoxyethyl, methylthioethyl, methylthiomethyl, methylthiopropyl, ethylthiomethyl, ethylthioethyl, propylthioethyl, butylthioethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, allyl, chloroallyl, butenyl, hexenyl, propargyl, or a group of the general formula ##STR10## wherein Ar represents unsubstituted phenyl or a phenyl group having a substituent or substituents optionally selected from the group consisting of fluorine, chlorine, bromine, methyl, ethyl, propyl, butyl, difluoromethyl, chlorodifluoromethyl, trifluoromethyl, 2,2,2-trifluoroethyl, methoxy, ethoxy, propoxy, butoxy, difluoromethoxy, chlorodifluoromethoxy, trifluoromethoxy, 2,2,2-trifluoroethoxy, methylthio, ethylthio, propylthio, difluoromethylthio, trifluoromethylthio, 2,2,2-trifluoroethylthio, dimethylamino, diethylamino, methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl, carboxy, phenoxy, optionally substituted heterocyclyl-oxy, (wherein the hetero ring of said heterocyclyl-oxy is selected from the group consisting of imidazole, pyrazole, triazole, oxazole, isoxazole, benzoxazole, thiazole, isothiazole, benzothiazole, oxadiazole, thiadiazole, tetrazole, pyridine, quinoline, isoquinoline, pyrimidine, pyridazine, pyrazine, quinazoline, quinoxaline, triazine, thiophene, benzothiophene, furan and benzofuran), methylenedioxy, difluoromethylenedioxy, ethylenedioxy, chlorodifluoroethylenedioxy, difluoroethylenedioxy, trifluoroethylenedioxy, tetrafluoroethylenedioxy, cyano and nitro; or Ar represents unsubstituted naphthyl or a substituted naphthyl group having a substituent or substituents optionally selected from the group consisting of fluorine, chlorine, bromine, methyl, ethyl, propyl, butyl, difluoromethyl, chlorodifluoromethyl, trifluoromethyl, 2,2,2-trifluoroethyl, methoxy, ethoxy, propoxy, butoxy, difluoromethoxy, chlorodifluoromethoxy, trifluoromethoxy, 2,2,2-trifluoroethoxy, methylthio, ethylthio, propylthio, difluoromethylthio, trifluoromethylthio, 2,2,2-trifluoroethylthio, dimethylamino, diethylamino, methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl, carboxy, phenoxy, optionally substituted heterocyclyl-oxy, (wherein the hetero ring of said heterocyclyl-oxy is selected from the group consisting of imidazole, pyrazole, triazole, oxazole, isoxazole, benzoxazole, thiazole, isothiazole, benzothiazole, oxadiazole, thiadiazole, tetrazole, pyridine, quinoline, isoquinoline, pyrimidine, pyridazine, pyrazine, quinazoline, quinoxaline, triazine, thiophene, benzothiophene, furan and benzofuran), methylenedioxy, difluoromethylenedioxy, ethylenedioxy, chlorodifluoroethylenedioxy, difluoroethylenedioxy, trifluoroethylenedioxy, tetrafluoroethylenedioxy, cyano and nitro; or Ar represents an unsubstituted or substituted five- or six-membered heterocyclic ring and their benzologues, wherein said hetero ring is selected from the group consisting of imidazole, pyrazole, triazole, oxazole, isoxazole, benzoxazole, thiazole, isothiazole, benzothiazole, oxadiazole, thiadiazole, tetrazole, pyridine, quinoline, isoquinoline, pyrimidine, pyridazine, pyrazine, quinazoline, quinoxaline, triazine, thiophene, and furan), having a substituent or substituents optionally selected from the group consisting of fluorine, chlorine, bromine, methyl, ethyl, propyl, butyl, difluoromethyl, chlorodifluoromethyl, trifluoromethyl, 2,2,2-trifluoroethyl, methoxy, ethoxy, propoxy, butoxy, difluoromethoxy, chlorodifluoromethoxy, trifluoromethoxy, 2,2,2-trifluoroethoxy, methylthio, ethylthio, propylthio, difluoromethylthio, trifluoromethylthio, 2,2,2-trifluoroethylthio, dimethylamino, diethylamino, methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl, carboxy, phenoxy, optionally substituted heterocyclyl-oxy, (wherein the hetero ring of said heterocyclyl-oxy is selected from the group consisting of imidazole, pyrazole, triazole, oxazole, isoxazole, benzoxazole, thiazole, isothiazole, benzothiazole, oxadiazole, thiadiazole, tetrazole, pyridine, quinoline, isoquinoline, pyrimidine, pyridazine, pyrazine, quinazoline, quinoxaline, triazine, thiophene, benzothiophene, furan and benzofuran), methylenedioxy, difluoromethylenedioxy, ethylenedioxy, chlorodifluoroethylenedioxy, difluoroethylenedioxy, trifluoroethylenedioxy, tetrafluoroethylenedioxy, cyano and nitro, R.sup.4 represents hydrogen or methyl, n is 0, 1 or 2, and R.sup.2 and R.sup.3 each independently represents methyl, ethyl, n-propyl, isopropyl, n-(iso-, sec-, tert-)butyl, trifluoromethyl, difluoromethyl, 2-methoxyethyl, ethoxymethyl, 2-ethoxyethyl, 2-methylthioethyl, allyl, 2-butenyl, 3-chloroallyl, propargyl, methoxy, ethoxy, n-propoxy, cyclopropyl, cyclopentyl, cyclohexyl, or optionally substituted phenyl or benzyl, having a substituent or substituents selected from the group consisting of fluorine, chlorine, bromine, methyl, ethyl, n-propyl, isopropyl, tert-butyl, trifluoromethyl, methoxy, ethoxy, trifluoromethoxy, methylthio, cyano and nitro, or R.sup.2 and R.sup.3 together with the adjacent nitrogen atom may form piperidino, morpholino, thiomorpholino, 2,3-dihydroindolyl or perhydroindolyl.

The compounds represented by the general formula (II) and employed as starting materials in the processes according to the present invention can be obtained by the processes disclosed in J. Am. Chem. Soc., vol. 81, pp. 3076-3079 (1959); J. Org. Chem. vol. 45, pp. 5130-5136 (1980) and Japanese Patent Application No. Hei 5-212153.

The compounds represented by the general formula (III) are well known.

The above-mentioned general definitions of radicals or explanations, or those mentioned as preferred, are applicable in a corresponding manner to the end products (I) and to the starting materials (II) and (III) and "intermediates" (IV). These definitions of radicals may be combined with one another, as desired.

Representative 1-substituted-5(4H)-tetrazolinones of the formula (II) include the following compounds:

1-phenyl-5(4H)-tetrazolinone, 1-(3,5-dimethylphenyl)-5(4H)-tetrazolinone, 1-(2-chlorophenyl)-5(4H)-tetrazolinone, 1-(2-chloro-3-methylphenyl)-5(4H)-tetrazolinone, 1-(2-chloro-4-trifluoromethylphenyl)-5(4H)-tetrazolinone, 1-methyl-5(4H)-tetrazolinone, 1-benzyl-5(4H)-tetrazolinone, 1-(3,4-tetrafluoroethylenedioxyphenyl)-5(4H)-tetrazolinone, 1-(2-chloro-5-pyridylmethyl)-5(4H)-tetrazolinone, 1-ethyl-5(4H)-tetrazolinone, 1-n-propyl-5(4H)-tetrazolinone, 1-isopropyl-5(4H)-tetrazolinone, 1-tert-butyl-5(4H)-tetrazolinone, 1-cyclopropyl-5(4H)-tetrazolinone, 1-cyclopentyl-5(4H)-tetrazolinone, 1-cyclohexyl-5(4H)-tetrazolinone, 1-(2,2,2-trifluoroethyl)-5(4H)-tetrazolinone, 1-(2-methoxyethyl)-5(4H)-tetrazolinone, 1-(2-ethylthioethyl)-5(4H)-tetrazolinone, 1-(2-methylthioethyl)-5(4H)-tetrazolinone, 1-allyl-5(4H)-tetrazolinone, 1-(3-chloroallyl)-5(4H)-tetrazolinone, 1-propargyl-5(4H)-tetrazolinone, 1-(2-fluorophenyl)-5(4H)-tetrazolinone, 1-(3-chlorophenyl)-5(4H)-tetrazolinone, 1-(3-trifluoromethylphenyl)-5(4H)-tetrazolinone, 1-(4-trifluoromethylphenyl)-5(4H)-tetrazolinone, 1-(4-chlorophenyl)-5(4H)-tetrazolinone, 1-(2-methylphenyl)-5(4H)-tetrazolinone, 1-(3-methylphenyl)-5(4H)-tetrazolinone, 1-(4-methylphenyl)-5(4H)-tetrazolinone, 1-(2-methoxyphenyl)-5(4H)-tetrazolinone, 1-(4-methoxyphenyl)-5(4H)-tetrazolinone, 1-(4-trifluoromethoxyphenyl)-5(4H)-tetrazolinone, 1-(4-trifluoromethylthiophenyl)-5(4H)-tetrazolinone, 1-(3-propylphenyl)-5(4H)-tetrazolinone, 1-(4-tert-butylphenyl)-5(4H)-tetrazolinone, 1-(2,4-dichlorophenyl)-5(4H)-tetrazolinone, 1-(2,6-dichlorophenyl)-5(4H)-tetrazolinone, 1-(2-chloro-6-methylphenyl)-5(4H)-tetrazolinone, 1-(3-chloro-4-trifluoromethylphenyl)-5(4H)-tetrazolinone, 1-�4-(2,4-dichlorophenoxy)phenyl!-5(4H)-tetrazolinone, 1-�4-(2-chloro-4-trifluoromethylphenoxy)phenyl!-5(4H)-tetrazolinone, 1-�4-(2,6-dichloro-4-trifluoromethylphenoxy)phenyl!-5(4H)-tetrazolinone, 1-(3-phenoxyphenyl)-5(4H)-tetrazolinone, 1-(3,4-difluoromethylenedioxyphenyl)-5(4H)-tetrazolinone, 1-�4-(3,5-dichloropyridin-2-yloxy)-phenyl!-5(4H)-tetrazolinone, 1-�3,5-bis(trifluoromethyl)phenyl!-5(4H)-tetrazolinone, 1-(2-cyanophenyl)-5(4H)-tetrazolinone, 1-(4-chloro-2-fluoro-5-isopropoxyphenyl)-5(4H)-tetrazolinone, 1-�4-chloro-2-fluoro-5-(methoxycarbonyl)methoxyphenyl!-5(4H)-tetrazolinone, 1-�4-chloro-2-fluoro-5-(n-pentyloxycarbonyl)methoxyphenyl!-5(4H)-tetrazolinone, 1-(7-fluoro-4-ethoxy-2H-1,4-benzoxazine-3(4H)-one-6-yl)-5(4H)-tetrazolinone 1-(7-fluoro-4-propargyl-2H-1,4-benzoxazine-3(4H)-one-6-yl)-5(4H)-tetrazolinone, 1-(6-fluoro-4-propargyl-2H-1,3-benzoxazole-2-one-5-yl)-5(4H)-tetrazolinone, 1-(6-fluoro-4-propargyl-2H-1,3-benzothiazole-2-one-5-yl)-5(4H)-tetrazolinone, 1-�4-chloro-2-fluoro-5-(methanesulfonylamino)phenyl!-5(4H)-tetrazolinone 1-(3-tert-butylisoxazol-5-yl)-5(4H)-tetrazolinone, 1-(5-tert-butylisoxazole-3-yl)-5(4H)-tetrazolinone, 1-(5-tert-butyl-1,3,4-thiazol-2-yl)-5(4H)-tetrazolinone, 1-(5-trifluoromethyl-pyridin-2-yl)-5(4H)-tetrazolinone, 1-(3-chloro-5-trifluoromethyl-pyridin-2-yl)-5(4H)-tetrazolinone, 1-(2-chloroethyl)-5(4H)-tetrazolinone, 1-(2-fluoroethyl)-5(4H)-tetrazolinone, and 1-3(fluoropropyl)-5(4H)-tetrazolinone.

Representative carbamoyl chlorides of the formula (III) include the following compounds:

N,N-dimethyl carbamoylchloride, N,N-diethyl carbamoylchloride, N-ethyl-N-methyl carbamoylchloride, N-ethyl-N-n-propyl carbamoylchloride, N-ethyl-N-isopropyl carbamoylchloride, N-ethyl-N-iso-butyl carbamoylchloride, N-ethyl-N-sec-butyl carbamoylchloride, N-ethyl-N-tert-butyl carbamoylchloride, N-ethyl-N-cyclopentyl carbamoylchloride, N-ethyl-N-cyclohexyl carbamoylchloride, N,N-di-n-propyl carbamoylchloride, N-n-propyl-N-isopropyl carbamoylchloride, N-n-propyl-N-cyclopentyl carbamoylchloride, N-n-propyl-N-cyclohexyl carbamoylchloride, N,N-di-isopropyl carbamoylchloride, N-isopropyl-N-cyclopentyl carbamoylchloride, N-isopropyl-N-cyclohexyl carbamoylchloride, N,N-di-n-butyl carbamoylchloride, N-n-butyl-N-cyclopropyl carbamoylchloride, N,N-diallyl carbamoylchloride, N,N-dipropargyl carbamoylchloride, N-methoxy-N-n-propyl carbamoylchloride, N-ethoxy-N-n-propyl carbamoylchloride, N-methyl-N-phenyl carbamoylchloride, N-ethyl-N-phenyl carbamoylchloride, N-n-propyl-N-phenyl carbamoylchloride, N-isopropyl-N-phenyl carbamoylchloride, N-isopropyl-N-(3-methylphenyl) carbamoylchloride, N-isopropyl-N-(4-chlorophenyl) carbamoylchloride, N-isopropyl-N-(4-fluorophenyl) carbamoylchloride, N-methyl-N-(2-trifluoromethylphenyl) carbamoylchloride, N-methyl-N-(3-trifluoromethylphenyl) carbamoylchloride, N-isopropyl-(3-trifluoromethylphenyl) carbamoylchloride, N-isopropyl-(3-n-propylphenyl) carbamoylchloride, 4-chlorocarbonyl-morpholine, 4-chlorocarbonyl-thiomorpholine, 4-chlorocarbonyl-2,6-dimethylmorpholine, 1-chlorocarbonyl-piperdine, 1-chlorocarbonyl-2,6-dimethylpiperidine, 1-chlorocarbonyl-2,3-dihydroindole, and 1-chlorocarbonyl-perhydroindole.

Process variant (a) according to the invention for the production of the compounds of formula (I) is preferably carried out using diluents. Representative suitable diluents include liquid aliphatic, cycloaliphatic and aromatic, optionally chlorinated, hydrocarbons such as benzene, toluene, xylene, chloroform, chlorobenzene, and the like; ethers such as dioxane, dimethoxyethane (DME), tetrahydrofuran (THF), and the like; ketones such as, for example, acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl iso-butyl ketone, and the like; nitrites such as acetonitrile, propionitrile, and the like; esters such as, for example, ethyl acetate, and the like; and liquid bases such as, for example, pyridine, and the like.

Process variant (a) according to the invention is carried out in the presence of 4-dimethylamino-pyridine, which functions not only as acid-binder but also as catalyst.

If 4-dimethylamino-pyridine is employed in only catalytic (sub-stoichiometric) amounts, then process variant (a) is carried out in the presence of an additional acid-binder (in at least stoichiometric amount).

Representative additional acid-binders include inorganic bases such as, for example, carbonates and bicarbonates of alkali metals such as, for example, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium carbonate, potassium carbonate, and the like; and, as organic bases there may be mentioned tertiary amines, dialkylaminoanilines and pyridines such as, for example, triethylamine, 1,1,4,4-tetramethylethylenediamine (TMEDA), N,N-dimethylaniline, N,N-diethylaniline, pyridine, 1,4-diazabicyclo-�2,2,2!octane (DABCO), and 1,8-diazabicyclo-�5,4,0!undec-7-ene (DBU).

In general, the process variant (a) is carried out at a temperature of from about 15.degree. C. to about 150.degree. C., preferably from about 50.degree. C. to about 130.degree. C.

Further, the reaction is preferably carried out under normal pressure, although it is also possible to employ a higher or reduced pressure.

In carrying out process variant (a) according to the invention, the desired compounds of the formula (I) can be obtained in high yields by reacting about 0.8 to 1.5 mols of the compound of the formula (III) per mol of the compound of the formula (II), in the presence of about 0.01 to about 0.5 mols of 4-dimethylamino-pyridine as well as 0.3 to 1.5 mols of an additional acid binder.

In carrying out the process variant (a) with the use of 4-dimethylamino-pyridine as sole acid binder, it may be used in the amount of from about 0.8 to about 1.5 mols, including the desired catalytic amount.

Process variant (b) according to the invention is preferably carried out using diluents. Solvents which are suitable for this purpose are virtually the same organic solvents as have been mentioned above in connection with the description of process variant (a) according to the invention.

The first step of process variant (b) is preferably carried out in the presence of an acid acceptor. Acid-binding agents which are suitable for this purpose are the same as have been mentioned above in connection with the description of process variant (a) according to the invention.

In the second step of process variant (b), there must be employed 4-dimethylamino-pyridine as catalyst for the isomerization reaction (carbamoyl-migration).

In general, the process variant (b) is carried out at a temperature of from about 15.degree. C. to about 150.degree. C., preferably from about 50.degree. C. to about 130.degree. C.

Further, the reaction is preferably carried out under normal pressure, although it is also possible to employ a higher or reduced pressure.

When the above-mentioned process variant (b) according to the present invention is carried out, the compounds of the general formulae (II) and (III), respectively, are reacted in approximately equimolar amounts, followed by reacting the thus prepared mixture of a compound of the general formula (I) and its isomer of the general formula (IV) with about 0.01 to about 0.5 mols of 4-dimethylamino-pyridine as catalyst, so as to obtain the desired tetrazolinones of the general formula (I) in high yields.

The processes according to the present invention are illustrated in the following non-limiting examples hereinbelow in conjunction with the accompanying drawings, wherein

FIG. 1 is a graph showing the NMR spectrum of 1-(2-chloro-6-methylphenyl)-5-(N,N-dipropylcarbamoyloxy)-tetrazole of the formula ##STR11## i.e. the "O-carbamoyl" isomer of 1-(2-chloro-6-methylphenyl)-4-(N,N-dipropylcarbamoyl)-5(4H)-tetrazolinone, the latter being described in Synthesis Examples 1-3 and also in Table 1 as Example No. 15.

The "O-carbamoyl" isomer has been synthesized according to Synthesis Example 3, first step, then isolated from the initial mixture of the O-/N-isomers.

FIG. 2 is a graph showing the IR spectrum of the same "O-carbamoyl" compound (neat) as in FIG. 1.

FIG. 3 is a graph showing the NMR spectrum of 1-(2-chloro-6-methylphenyl)-4-(N,N-dipropylcarbamoyl)-5(4H)-tetrazolinone, according to the invention, as described in Synthesis Examples 1-3 and also in Table 1 as Example No. 15.

FIG. 4 is a graph showing the IR spectrum of the same compound (in nujol), according to the invention, as in FIG. 3.

FIG. 5 is a graph showing the NMR spectrum of a (71:29)-mixture of 1-(2-chloro-6-methylphenyl)-4-(N,N-dipropylcarbamoyl)-5(4H)-tetrazolinone and its "O-carbamoyl" isomer, said mixture being obtained according to the first step of Synthesis Example 3.

EXAMPLES

Synthesis Example 1

�process variant (a)! ##STR12## 1(2-chloro-6-methylphenyl)-5(4H)-tetrazolinone (0.63 g) and 4-dimethylamino-pyridine (0.44 g) were dissolved in toluene (15 ml) and then dipropylcarbamoyl chloride (0.59 g) was added to the resulting solution, followed by a six-hour refluxing. After the completion of the reaction, the reaction product was purified according to conventional procedure, so as to obtain the desired 1-(2-chloro-6-methylphenyl)-4-(N,N-dipropylcarbamoyl)-5(4H)-tetrazolinone (0.90 g), having a melting point (m.p.) in the range of from 66.5.degree. to 68.5.degree. C. in a yield of 89% of theory.

N-selectivity: 100% (FIGS. 3 and 4).

Synthesis Example 2

�process variant (a)! ##STR13## 1-(2-chloro-6-methylphenyl)-5(4H)-tetrazolinone (0.63 g), potassium carbonate (0.50 g) and 4-dimethylamino-pyridine (0.037 g) were dissolved in acetonitrile (15 ml) and then dipropylcarbamoyl chloride (0.59 g) was added to the resulting solution, followed by a six-hour refluxing. After the completion of the reaction, the reaction product was purified according to conventional procedure, so as to obtain the desired 1-(2-chloro-6-methylphenyl)-4-(N,N-dipropylcarbamoyl)-5(4H)-tetrazolinone (0.87 g), having a m.p. in the range of from 66.5.degree. to 68.5.degree. C. in a yield of 86% of theory.

N-selectivity: 100% (FIGS. 3 and 4).

Synthesis Example 3

�process variant (b)! ##STR14## 1-(2-chloro-6-methylphenyl)-5(4H)-tetrazolinone (2.11 g) and potassium carbonate (1.66 g) were mixed in acetonitrile (50 ml) and then dipropylcarbamoyl chloride (1.96 g) was added to the resulting solution, followed by a six-hour refluxing. After the completion of the reaction, the reaction product was purified according to conventional procedure, so as to obtain a mixture (2.93 g) of the desired N-carbamoyl product and the isomeric O-carbamoyl compound (FIG. 5). The N-selectivity of the reaction yielding this mixture turned out to be 71%.

The resulting mixture and 4-dimethylamino-pyridine (0.11 g) were dissolved in acetonitrile (40 ml), followed by a six-hour refluxing. After the completion of the reaction, the reaction product was purified according to conventional procedure, so as to obtain the desired 1-(2-chloro-6-methylphenyl)-4-(N,N-dipropylcarbamoyl)-5(4H)-tetrazolinone (2.51 g), having a m.p. in the range of from 66.5.degree. to 68.5.degree. C. in a yield of 86% of theory.

N-selectivity: 100% (FIGS. 3 and 4).

If desired, the two isomers contained in the above mixture can be separated and isolated in clean form by conventional methods, to determine their individual properties. Thus, the NMR- and IR-spectra of the O-carbamoyl isomer is shown in FIGS. 1 and 2, respectively, while the NMR- and IR-spectra of the N-carbamoyl isomer is shown in FIGS. 3 and 4, respectively.

Further Examples

In analogous manner as described in Synthesis Examples 1-3, there can be obtained the compounds shown in Table 1 which follows; for all listed compounds the N-selectivity proved to be 100% as in the case of the N-carbanoyl compound obtained in said foregoing Synthesis Examples 1-3, such compound being also included in Table 1 as Example No. 15.

TABLE 1__________________________________________________________________________ ##STR15##Example mp (.degree.C.)/No. R.sup.1 R.sup.2 R.sup.3 n.sub.D.sup.20__________________________________________________________________________1 propyl ethyl ethyl 1.47872 isopropyl ethyl ethyl 1.47633 t-butyl ethyl ethyl 1.47604 benzyl ethyl ethyl 1.53215 phenyl ethyl ethyl 57-61.degree. C.6 2-chlorophenyl ethyl ethyl 1.54157 3-chlorophenyl ethyl ethyl 68-75.degree. C.8 4-chlorophenyl ethyl ethyl 89-90.5.degree. C.9 2-methylphenyl ethyl ethyl 68.5-71.5.degree. C.10 2-ethylphenyl ethyl ethyl 1.526311 2-isopropylphenyl ethyl ethyl 1.517212 2-chloro-6-methyl- ethyl ethyl 1.5282 phenyl13 2-chloro-6-methyl- methyl methyl 96-98.degree. C. phenyl14 2-chloro-6-methyl- ethyl ethyl 1.5380 phenyl15 2-chloro-6-methyl- propyl propyl 66.5-68.5.degree. C. phenyl16 2-chloro-6-methyl- propyl cyclopentyl 92-93.degree. C. phenyl17 2-chlorophenyl ethyl propyl 1.545118 2-chlorophenyl ethyl butyl 1.529219 2-chlorophenyl propyl propyl 1.532520 2-chlorophenyl propyl cyclopentyl 70-73.5.degree. C.21 2-chlorophenyl ethyl cyclohexyl 77.5-79.5.degree. C.22 3-chloro-4-isopropyl- ethyl ethyl 69.5-72.5.degree. C. phenyl23 3-chloro-4-isopropyl- allyl allyl 47-51.degree. C. phenyl24 3-chloro-4-isopropyl- propargyl propargyl 1.5489 phenyl25 3-chloro-4-isopropyl- methyl phenyl 1.5723 phenyl26 3-chloro-4-isopropyl- phenyl phenyl 113- phenyl 116.5.degree. C.27 3-chloro-4-isopropyl- (CH.sub.2).sub.5 67-70.degree. C. phenyl28 3-chloro-4-isopropyl- (CH.sub.2).sub.2 O(CH.sub.2).sub.2 89.5-92.5.degree. C. phenyl29 3-chloro-4-methyl- ethyl ethyl 52-57.degree. C. phenyl30 3-chloro-4-trifluoro- ethyl ethyl 64.5-69.5.degree. C. methoxyphenyl31 2-chloroethyl ethyl ethyl 1.501332 2-chloroethyl ethyl isopropyl 1.532933 3-chloropropyl phenyl isopropyl 1.531534 2-methoxyethyl ethyl ethyl35 2-methylthioethyl ethyl ethyl36 cyclopentyl ethyl cyclohexyl37 cyclohexyl ethyl cyclohexyl38 allyl ethyl ethyl39 3-chloroallyl ethyl ethyl40 propargyl ethyl ethyl41 1-phenethyl ethyl ethyl42 2-trifluoromethyl- ethyl ethyl 90-92.degree. C. phenyl43 2-methoxyphenyl ethyl ethyl 76-78.degree. C.44 2-methylthiophenyl ethyl ethyl 82-84.degree. C.45 3-chloro-4-trifluoro- ethyl ethyl 61.5-65.5.degree. C. methylthiophenyl46 2-dimethylamino- ethyl ethyl phenyl47 2-methoxycarbonyl- ethyl ethyl 1.5332 phenyl48 4-phenoxyphenyl ethyl ethyl 1.570649 3,4-methylenedioxy- ethyl ethyl phenyl50 3,4-ethylenedioxy- ethyl ethyl phenyl51 2-nitropbenyl ethyl isopropyl 1.555652 2-cyanophenyl ethyl isopropyl53 6-chloro-3-pyridyl- ethyl ethyl methyl54 ##STR16## ethyl ethyl55 3-tert-butyl-5- ethyl ethyl isoxazolyl56 5-tert-butyl-1,3,4- ethyl ethyl thiadiazole-2-yl57 5-trifluoromethyl-2- ethyl ethyl pyridyl58 3-chloro-5-trifluoro- ethyl ethyl methyl-2-pyridyl59 2-chloro-6-methyl- methyl propyl 92-94.5.degree. C. phenyl60 2-chloro-6-methyl- methyl isopropyl 120-123 .degree. C. phenyl61 2-chloro-6-methyl- ethyl isopropyl 1.5288 phenyl62 2-chloro-6-methyl- ethyl tert-butyl 1.5272 phenyl63 2-chloro-6-methyl- propyl sec-butyl 1.5301 phenyl64 2-chloro-6-methyl- isopropyl isopropyl 1.5220 phenyl65 2-chloro-6-methyl- butyl butyl 1.5202 phenyl66 2-chloro-6-methyl- isobutyl isobutyl 86-89.degree. C. phenyl67 2-chloro-6-methyl- methyl butyl 1.5322 phenyl68 2-chlorophenyl 2-chloro- 2-chloro- ethyl ethyl69 2-chlorophenyl propyl 2,2,2-tri- fluoroethyl70 2-chlorophenyl 2-methoxy- 2-methoxy- ethyl ethyl71 2-chlorophenyl 2-methyl- 2-methyl- thioethyl thioethyl72 2-chlorophenyl 3-chloro- 3-chloroallyl allyl73 2-chlorophenyl ethoxy ethyl74 2-chlorophenyl 3-chloro- ethyl allyloxy75 2-chlorophenyl cyclopropyl propyl76 2-chlorophenyl benzyl ethyl77 2-chlorophenyl 3-chloro- ethyl benzyl78 2-chloroethyl 4-fluoro- isopropyl 1.5221 phenyl79 2-chloroethyl 3-methyl- isopropyl phenyl80 2-chloroethyl 4-trifluoro- isopropyl methyl- phenyl81 2-chloroethyl 2-methoxy- isopropyl phenyl82 2-chloroethyl 4-trifluoro- isopropyl methoxy- phenyl83 2-chloroethyl 4-methyl- isopropyl thiophenyl84 2-chloroethyl 4-trifluoro- isopropyl methyl- thiophenyl85 2-chloroethyl 4-nitro- isopropyl phenyl86 2-chloroethyl 4-cyano- isopropyl phenyl87 2-chloroethyl (CH.sub.2).sub.2 S(CH.sub.2).sub.2__________________________________________________________________________

It will be understood that the specification and examples are illustrative but not limitative of the present invention and that other embodiments within the spirit and scope of the invention will suggest themselves to those skilled in the art.

Claims

1. A process for selectivity producing a 1,4-disubstituted-5(4H)-tetrazolinone of the formula ##STR17## wherein R.sup.1 represents C.sub.1-2 alkyl, C.sub.1-6 haloalkyl, C.sub.2-8 alkoxyalkyl, C.sub.2-8 alkylthioalkyl, C.sub.3-8 cycloalkyl, C.sub.3-8 alkenyl, C.sub.3-8 haloalkenyl, C.sub.3-8 alkynyl, or ##STR18## wherein Ar represents optionally substituted phenyl wherein the substituents are selected from the group consisting of halogen, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4 alkoxy, C.sub.1-4 haloalkoxy, C.sub.1-4 alkylthio, C.sub.1-4 haloalkylthio, C.sub.1-4 alkoxy-carbonyl, carboxyl, phenoxy, heterocyclyl-oxy, methylene dioxy, halomethylene dioxy, ethylene dioxy, haloethylene dioxy, cyano, nitro and --NR.sup.5 R.sup.6 ;

and the hetero ring of said heterocycloxy is selected from the group consisting of imidazolyl, pyrazolyl, triazolyl, pyridyl, thienyl, benzothienyl, furan and benzofuran; or

Ar represents an optionally substituted naphthyl wherein the substituents are selected from the group consisting of consisting of halogen, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4 alkoxy, C.sub.1-4 haloalkoxy, C.sub.1-4 alkylthio, C.sub.1-4 haloalkylthio, C.sub.1-4 alkoxycarbonyl, carboxyl, phenoxy, heterocyclyl-oxy, methylene dioxy, halomethylene dioxy, ethylene dioxy, haloethylene dioxy, cyano, nitro and --NR.sup.5 R.sup.6 ;

and the hetero ring of said heterocyclyl-oxy is selected from the group consisting of imidazolyl, pyrazolyl, triazolyl, pyridyl, thienyl, benzothienyl, furan and benzofuran; or

Ar represents an optionally substituted five- or six-membered hetero-cyclic ring wherein said hetero ring is selected from the group consisting of imidazolyl, pyrazolyl, triazolyl, pyridyl, thienyl, and furan; wherein the substituents are selected from the group consisting of halogen, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4 alkoxy, C.sub.1-4 haloalkoxy, C.sub.1-4 alkylthio, C.sub.1-4 haloalkylthio, C.sub.1-4 alkoxy-carbonyl, carboxyl, phenoxy, heterocyclyl-oxy, methylene dioxy, halomethylene dioxy, ethylene dioxy, haloethylene dioxy, cyano, nitro and --NR.sup.5 R.sup.6 ; and the hetero ring of said heterocyclyl-oxy is selected from the group consisting of imidazolyl, pyrazolyl, triazolyl, pyridyl, thienyl, benzothienyl, furan and benzofuran;

R.sup.4 represents hydrogen or C.sub.1-4 alkyl,

n represents 0, 1, 2, 3, or 4,

R.sup.5 and R.sup.6 are the same or different and represent H or C.sub.1-4 alkyl,

R.sup.2 and R.sup.3 each independently represent C.sub.1-8 alkyl, C.sub.1-6 halogenoalkyl, C.sub.2-6 alkoxyalkyl, C.sub.2-6 alkylthioalkyl, C.sub.2-6 alkenyl, C.sub.2-6 haloalkenyl, C.sub.3-6 alkynyl, C.sub.1-4 alkoxy, C.sub.1-4 haloalkoxy, C.sub.3-8 cycloalkyl, optionally substituted phenyl or benzyl wherein the substituents are selected from the group consisting of fluorine, chlorine, bromine, methyl, ethyl, n-propyl, isopropyl, tert-butyl, trifluoromethyl, methoxy, ethoxy, isopropoxy, difluoromethoxy, trifluoromethoxy, methylthio, ethoxy, isopropoxy, difluoromethoxy, trifluoromethoxy, methylthio, ethylthio, trifluoromethylthio, 2,2,2-trifluoroethylthio, cyano and nitro, or

R.sup.2 and R.sup.3 together with the adjacent nitrogen atom form piperidino, 2,6-dimethylpiperidino, 2,3-dihydroindolyl or perhydroindolyl,

which comprises reacting a compound of the formula ##STR19## with a compound of the formula ##STR20## in the presence of, 4-dimethylaminopyridine which functions as a catalyst and an acid binder, optionally in the presence of a diluent and an additional acid binder at a temperature of 15.degree. C. to 150.degree. C.

2. The process according to claim 1, which contains 0.8 to 1.5 mols of the compound of formula (III) per mol of formula (II), about 0.01 to about 0.5 mols of 4-dimethylaminopyridine and about 0.3 to 1.5 mols of an additional acid binder.

3. The process according to claim 1 wherein the temperature is about 50.degree. C. to about 130.degree. C.

4. A process for selectively producing a 1,4-disubstituted-5(4H)-tetrazolinones of the formula ##STR21## wherein R.sup.1 represents C.sub.1-12 alkyl, C.sub.1-6 haloalkyl, C.sub.2-8 alkoxyalkyl, C.sub.2-8 alkylthioalkyl, C.sub.3-8 cycloalkyl, C.sub.3-8 alkenyl, C.sub.3-8 haloalkenyl, C.sub.3-8 alkynyl, or ##STR22## wherein Ar represents optionally substituted phenyl wherein the substituents are selected from the group consisting of halogen, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4 alkoxy, C.sub.1-4 haloalkoxy, C.sub.1-4 alkylthio, C.sub.1-4 haloalkylthio, C.sub.1-4 alkoxy-carbonyl, carboxyl, phenoxy, heterocyclyl-oxy, methylene dioxy, halomethylene dioxy, ethylene dioxy, haloethylene dioxy, cyano, nitro and --NR.sup.5 R.sup.6 ;

and the hetero ring of said heterocycloxy is selected from the group consisting of imidazolyl, pyrazolyl, triazolyl, pyridyl, thienyl, benzothienyl, furan and benzofuran; or

Ar represents an optionally substituted naphthyl wherein the substituents are selected from the group consisting of consisting of halogen, C .sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4 alkoxy, C.sub.1-4 haloalkoxy, C.sub.1-4 alkylthio, C.sub.1-4 haloalkylthio, C.sub.1-4 alkoxycarbonyl, carboxyl, phenoxy, heterocyclyl-oxy, methylene dioxy, halomethylene dioxy, ethylene dioxy, haloethylene dioxy, cyano, nitro and --NR.sup.5 R.sup.6 ;

and the hetero ring of said heterocyclyl-oxy is selected from the group consisting of imidazolyl, pyrazolyl, triazolyl, pyridyl, thienyl, benzothienyl, furan and benzofuran; or

Ar represents an optionally substituted five- or six-membered hetero-cyclic ring wherein said hetero ring is selected from the group consisting of imidazolyl pyrazolyl, triazolyl, pyridyl, thienyl, and furan; wherein the substituents are selected from the group consisting of halogen, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4 alkoxy, C.sub.1-4 haloalkoxy, C.sub.1-4 alkylthio, C.sub.1-4 haloalkylthio, C.sub.1-4 alkoxy-carbonyl, carboxyl, phenoxy, heterocyclyl-oxy, methylene dioxy, halomethylene dioxy, ethylene dioxy, haloethylene dioxy, cyano, nitro and --NR.sup.5 R.sup.6 ; and the hetero ring of said heterocyclyl-oxy is selected from the group consisting of imidazolyl, pyrazolyl, triazolyl, pyridyl, thienyl, benzothienyl, furan and benzofuran;

R.sup.4 represents hydrogen or C.sub.1-4 alkyl,

n represents 0, 1, 2, 3, or 4,

R.sup.5 and R.sup.6 are the same or different and represent H or C.sub.1-4 alkyl,

R.sup.2 and R.sup.3 each independently represent C.sub.1-8 alkyl, C.sub.1-6 halogenoalkyl, C.sub.2-6 alkoxy alkyl, C.sub.2-6 alkylthioalkyl, C.sub.2-6 alkenyl, C.sub.2-6 haloalkenyl, C.sub.3-6 alkynyl, C.sub.1-4 alkoxy, C.sub.1-4 haloalkoxy, C.sub.3-8 cycloalkyl, optionally substituted phenyl or benzyl wherein the substituents are selected from the group consisting of fluorine, chlorine, bromine, methyl, ethyl, n-propyl, isopropyl, tert-butyl, trifluoromethyl, methoxy, ethoxy, isopropoxy, difluoromethoxy, trifluoromethoxy, methylthio, ethoxy, isopropoxy, difluoromethoxy, trifluoromethoxy, methylthio, ethylthio, trifluoromethylthio, 2,2,2-trifluoroethylthio, cyano and nitro, or

R.sup.2 and R.sup.3 together with the adjacent nitrogen atom form piperidino, 2,6-dimethylpiperidino, 2,3-dihydroindolyl or perhydroindolyl,

which comprises

(1) reacting a compound of the formula ##STR23## with a compound of the formula ##STR24## optionally in the presence of a solvent and of an acid-binder other than 4-dimethylaminopyridine to obtain a mixture of ##STR25## 2) reacting said mixture with 4-dimethylaminopyridine optionally in the presence of a solvent at a temperature from about 15.degree. C. to 150.degree. C.

5. The process according to claim 4, wherein the temperature is about 50.degree. C. to 150.degree. C.

6. The process according to claim 4, which contains approximately equal molar amounts of the compound of formula (I) and formula (II) in the first step and about 0.01 to about 0.5 mols of 4-dimethylaminopyridine in step 2.