2,6-Dinitroaniline herbicides

Abstract

This invention is novel substituted 2,6-dinitroaniline compounds and preemergence herbicidal methods and compositions employing the substituted 2,6-dinitroaniline compounds.

Description

The invention is novel substituted 2,6-dinitroaniline compounds, and preemergence herbicidal methods and compositions employing the substituted 2,6-dinitroaniline compounds.

The 2,6-dinitroaniline compounds of the invention are compounds of the formula: ##STR1## wherein Y represents halogen, alkyl C.sub.1 -C.sub.4, alkenyl C.sub.2 -C.sub.4, CF.sub.3, CN or --SO.sub.2 NR.sub.3 R.sub.4 ;

Z represents alkyl C.sub.1 -C.sub.4, alkenyl C.sub.2 -C.sub.4 or monosubstituted alkyl C.sub.1 -C.sub.4 where the substituent is halogen, alkoxy C.sub.1 -C.sub.4 or NR.sub.3 R.sub.4 ; R.sub.3 and R.sub.4 each represent hydrogen or alkyl C.sub.1 -C.sub.4 ; and R.sub.1 and R.sub.2 taken together represent piperidino, pyrrolidino, 2,6-dimethylmorpholino or morpholino.

The above-identified compounds are highly effective herbicidal agents and particularly efficacious are those represented by the following structural formula: ##STR2## wherein R.sub.1 and R.sub.2 when taken together with the nitrogen to which they are attached represent a member selected from the group consisting of piperidino, pyrrolidino, 2,6-dimethylmorpholino and morpholino;

Z represents CH.sub.3 or --CH.sub.2 OCH.sub.3 and Y is CH.sub.3, C.sub.3 H.sub.7 -n, C.sub.3 H.sub.7 -i, C.sub.4 H.sub.9 -i, sec-C.sub.4 H.sub.9, Cl, CF.sub.3 or C.sub.2 H.sub.5.

These compounds represent a preferred class of compounds within the above-broader generic class and show a marked superiority in herbicidal performance.

Illustrative lower alkyl substituents are methyl, ethyl, n-propyl, iso-propyl, n-butyl, t-butyl, sec-butyl, and the like.

Illustrative loweralkenyl substituents are ethenyl 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, and the like.

Illustrative halogen substituents are fluoro, chloro, bromo and iodo groups.

The herbicidal methods of the invention comprise application of a herbicidally effective amount of one or more compounds of Formula III below to the soil containing the seeds of undesirable plant species to be controlled, ##STR3## wherein Y represents halogen, alkyl C.sub.1 -C.sub.4, alkenyl C.sub.2 -C.sub.4, CF.sub.3, CN or --SO.sub.2 NR.sub.3 R.sub.4 ;

Z represents alkyl C.sub.1 -C.sub.4, alkenyl C.sub.2 -C.sub.4 or monosubstituted alkyl C.sub.1 -C.sub.4 where the substituent is halogen, alkoxy C.sub.1 -C.sub.4 or --NR.sub.3 R.sub.4 ; R.sub.3 and R.sub.4 each represent hydrogen or alkyl C.sub.1 -C.sub.4 ; and R.sub.1 and R.sub.2 taken together represent piperidino, pyrrolidino, 2,6-dimethylmorpholino or morpholino.

Preferably, application of these compounds, or active ingredients is made using the herbicidal compositions described below with conventional application methods.

The 2,6-dinitroaniline compounds are prepared by a nucleophilic substitution of a 1-substituent, such as, a chloro group, with the appropriately substituted amine. While chloro is a preferred substituent, and the discussion is in terms thereof other conventional equivalent substituents, such as, bromo or iodo are included herein. The displacement may be conducted with or without an organic solvent, such as toluene, benzene or preferably xylene.

The reaction, which is graphically illustrated below, is carried out by heating the reactants, preferably between 50.degree. C. and 150.degree. C. ##STR4##

For purposes of further discussion, the active ingredients may be considered as falling into one of six classes of compounds, labeled as Types A through F. In Type A compounds, Y is alkyl C.sub.1 -C.sub.4. In Type B compound, Y is alkenyl C.sub.2 -C.sub.4. In Type C compounds, Y is halogen and preferably chlorine or bromine. In Type D compounds, Y is --SO.sub.2 NR.sub.3 R.sub.4, where R.sub.3 and R.sub.4 are as described above. In Type E compounds, Y is trifluoromethyl. In Type F compounds, Y is CN.

Type A compounds, where Y and Z are lower alkyl groups, can be prepared by reacting the appropriately substituted 2,6-dinitrochlorobenzene with the appropriate amine.

The chlorobenzene intermediates for Type A compounds can be prepared by reacting an appropriately substituted aniline with ethyl chloroformate in benzene at about 10.degree. C. to 50.degree. C. to yield the correspondingly substituted N-(ethoxycarbonyl)-3,4-substituted aniline. This product is then treated with a cold solution of sulfuric and nitric acid, i.e., at about 0.degree. C. to 20.degree. C. to obtain the N-(ethoxycarbonyl)-3,4-disubstituted-2,6-dinitroaniline. Reaction of the thus-formed product with sulfuric acid at an elevated temperature, preferably between about 100.degree. C. and 150.degree. C., converts the N-(ethoxycarbonyl) product to the 3,4-disubstituted-2,6-dinitroaniline. The amino group is replaced by a chlorine atom by first heating the compound with glacial acetic acid and diazotizing the amine with a mixture of sodium nitrite in sulfuric acid. This is followed by treating the diazotized mixture with a mixture of cuprous chloride in hydrochloric acid, and then heating the thus-formed mixture to about 40.degree. C. to 80.degree. C. to obtain the chlorinated compound.

Selected chlorinated intermediates for Type A compounds can also be prepared by reacting a mixture of fuming sulfuric acid and fuming nitric acid with 4-chloro-o-xylene at about 10.degree. C. to 60.degree. C., pouring the mixture over ice and separating the precipitated solid. Recrystallization of the solid from methanol or other lower alkyl alcohol C.sub.1 -C.sub.4 yields the high purity product.

Illustrative Type A compounds which are readily prepared by the preceding procedure include, for example: 3,4-dimethyl-2,6-dinitro-N,N-di-n-propylaniline; N-ethyl-N-n-propyl-3,4-dimethyl-2,6-dinitroaniline; N,N-di-n-butyl-3,4-dimethyl-2,6-dinitroaniline; 3,4-dimethyl-2,6-dinitro-N-oxydiethyleneaniline; 3,4-dimethyl-2,6-dinitro-N-pentamethyleneaniline; 3,4-dimethyl-2,6-dinitro-N-tetramethyleneaniline; N,N-dicyclopropyl-3,4-dimethyl-2,6-dinitroaniline; N,N-diallyl-3,4-dimethyl-2,6-dinitroaniline; N-ethyl-N,3,4-trimethyl-2,6-dinitroaniline; N,3,4-trimethyl-2,6-dinitro-N-(cyclopropyl)aniline; N,N-dipropargyl-3,4-dimethyl-2,6-dinitroaniline; N,N-bis(1-buten-3-yl)-3,4-dimethyl-2,6-dinitroaniline; N-ethyl-3-isopropyl-4-methyl-2,6-dinitroaniline; 3-sec-butyl-4-methyl-2,6-dinitro-N,N-dimethylaniline; N,N,3,4-tetramethyl-2,6-dinitroaniline; N,N-diethyl-3,4-dimethyl-2,6-dinitroaniline; N,3,4-trimethyl-2,6-dinitro-N-propylaniline; N-cyclobutyl-N,3,4-trimethyl-2,6-dinitroaniline; 3,4-dimethyl-2,6-dinitro-N,N-(dicyclopropylmethyl)aniline; N,3,4-trimethyl-2,6-dinitroaniline; N-ethyl-3,4-dimethyl-2,6-dinitroaniline; 3,4-dimethyl-2,6-dinitro-N-(cyclopropyl)aniline; N-isopropyl-3,4-dimethyl-2,6-dinitroaniline; N-allyl-3,4-dimethyl-2,6-dinitroaniline; N-n-butyl-3,4-dimethyl-2,6-dinitroaniline; N-sec-butyl-3,4-dimethyl-2,6-dinitroaniline; 3,4-dimethyl-2,6-dinitro-N-3-pentylaniline, 4-(4-ethyl-.alpha.-methoxy-2,6-dinitro-m-tolyl)-2,6-dimethylmorpholine, 4-(2,6-dinitro-3,4-xylyl)-morpholine, 4-(2,6-dinitro-3-xylyl)-2,6-dimethylmorpholine, 1-(2,6 -dinitro-3,4-xylyl)pyrrolidine, 1-(2,6-dinitro-3,4-xylyl)piperidine, and 1-(4-ethyl-.alpha.-methoxy-2,6-dinitro-m-tolyl)-pyrrolidine.

The 3,4-diethyl derivatives, 3-methyl-4-ethyl derivatives, 3-ethyl-4-methyl, 3-ethyl-4-propyl, 3,4-diisopropyl, 3,4-di-n-propyl, 3,4-di-n-butyl, 3,4-diisobutyl, 3-propyl-4-butyl, and 3-methyl-4-isopropyl derivatives of the above-named 2,6-di-nitroanilines, are likewise prepared by the above procedure, utilizing the appropriate 3,4-disubstituted-2,6-dinitrochlorobenzene and appropriate amine.

Type B compounds, where Y represents a lower alkenyl C.sub.2 -C.sub.4 group, are prepared by the procedure described above. The reaction is preferably run in xylene at a temperature between about 50.degree. C. and 150.degree. C. and involves the reaction of a 3-substituted-4-alkenyl-2,6-dinitrochlorobenzene with the appropriate amine. In this reaction, Z is preferably methyl or ethyl, although it may be any of the radicals previously described for it.

Illustrative Type B compounds, which can be prepared by this procedure include, for example: N-sec-butyl-4-isobutenyl-3-methyl-2,6-dinitroaniline; 4-isopropenyl-3-methyl-2,6-dinitro-N,N-di-n-propylaniline; N,3-di-methyl-2,6-dinitro-4-n-propenylaniline; and 4-isopropenyl-N,N,3,5-tetramethyl-2,6-dinitroaniline.

A preferred method for the preparation of Type C compounds wherein Y is halogen and Z is lower alkyl involves the reaction of a dihalo-dinitroalkylbenzene, such as 3,6-dihalo-2,4-dinitrotoluene, with the appropriate amine. The reaction is preferably carried out in the presence of an organic solvent, such as C.sub.1 -C.sub.4 alcohols, toluene and the like. The reaction may be conducted at room temperature, although heating is generally advantageously employed.

Type D compounds, in which Y represents an --SO.sub.2 NR.sub.3 R.sub.4 group, can be synthesized by reacting, at an elevated temperature, a 1-chloro-3-substituted-2,6-dinitro-4-sulfonamide or alkyl-substituted sulfonamide with an amide, preferably in an organic solvent, such as xylene, toluene or the like. The intermediates for this reaction can be prepared by reacting m-chloro-toluene with sulfuric acid and potassium nitrate to form the potassium 4-chloro-3,5-dinitro-o-toluenesulfonate which is converted to the corresponding o-toluenesulfonyl chloride by reaction with phosphorus pentachloride and phosphorus oxychloride. The thus-formed toluenesulfonyl chloride is then treated with ammonia, alkylamine or dialkylamine in acetone at 0.degree. C. to 25.degree. C. to obtain the corresponding o-toluenesulfonamide. Treatment of this product with the appropriate amine (i.e., ##STR5## where R.sub.1 and R.sub.2 are as described above) then yields the 4-sulfamoyl or alkyl-substituted sulfamoyl-2,6-dinitroaniline of this invention.

Illustrative Type D compounds which can be prepared by the process of the instant invention are: 3-methyl-2,6-dinitro-N.sup.4, N.sup.4 -di-n-propyl-4-sulfamoylaniline; N.sup.4 -sec-butyl-3-methyl-4-(methylsulfamoyl)-2,6-dinitroaniline; 4-(dimethylsulfamoyl)-3-methyl-2,6-dnitro-N.sup.4 -3-pentylaniline; N.sup.4,3-dimethyl-2,6-dinitro-4-sulfamoylaniline; 3-methyl-N.sup.4 -oxydiethylene-2,6-dinitro-4-sulfamoylaniline; 3-methyl-4-(methylsulfamoyl)-2,6-dinitro-N.sup.4 -pentamethyleneaniline, 3,5-dimethyl-4-(methylsulfamoyl)-2,6-dinitro-N.sup.4 -tetramethyleneaniline.

Type E compounds can be prepared by reacting the appropriate 3-substituted-4-trifluoromethyl-2,6-dinitrochlorobenzene with the appropriate amine, preferably by heating the reactants in the presence of an organic solvent such as benzene, toluene or the like.

Preparation of chlorobenzene intermediates for use in this reaction are described by Newman and Pinkus, Journal of Organic Chemistry 19: 978, and Von Auwers and Julicker, Chemische Berichte 55: 2167 (1922). For example, 4-methylphenol may be treated with aluminum trichloride in carbon tetrachloride to obtain 2,5-cyclohexadien-1-one which is treated with phosphorus-pentachloride to yield 3-methyl-4-trichloromethylchlorobenzene. When the latter compound is treated with SbF.sub.3, 1-chloro-3-methyl-4-(trifluoromethyl)benzene is obtained. This product may be nitrated using a mixture of nitric acid and sulfuric acid to give the intermediate, 1-chloro-3-methyl-2,6-dinitro-4-(trifluoromethyl)benzene.

Illustrative Type E compounds which can be prepared by this process include, for example: 3-methyl-2,6-dinitro-N,N-di-n-propyl-4-(trifluoromethyl)aniline; N-sec-butyl-3-methyl-2,6-dinitro-4-(trifluoromethyl)aniline; 3-methyl-2,6-dinitro-N-3-pentyl-4-(trifluoromethyl)aniline; N-cyclopropyl-3-methyl-2,6-dinitro-4-(trifluoromethyl)aniline; and 3-ethyl-2,6-dinitro-N-isopropyl-4-(trifluoromethyl)aniline.

Type F compounds are prepared by reacting the appropriate 3,5-disubstituted-4-cyano-2,6-dinitrochlorobenzene with the appropriate amine.

o-Toluoyl chlorides may be prepared by reacting 3,5-dinitro-4-chloro-o-toluic acid with phosphorus pentachloride. The resulting o-toluoyl chloride is then treated with ammonia in cold acetone to yield the corresponding 3,5-dinitro-4-chloro-o-toluamide which is converted to the corresponding nitrile by reaction with phosphorus pentoxide or preferably with POCl.sub.3.

The preemergence herbicidal compositions of the present invention are solid or liquid formulations comprising an effective amount of one or more of the 2,6-dinitroaniline compounds of Formula I, or preferably Formula II.

Preparation of the compositions broadly involves admixing an effective amount of the herbicidal agent and adjuvant.

Use of the compositions broadly involves application of an effective amount of the compounds or preferably the compositions to the soil containing seeds of the plants to be controlled.

Typical formulations include, for example, dusts, dust concentrates, wettable powders, granulars, and the like. Application by conventional methods and equipment is usually made at rates of from about 1/8 pound per acre to about 20 pounds per acre and preferably 1/4 to 8 pounds per acre of active material.

Dusts are generally prepared by grinding together from about 1% to 15% by weight of the active material with from about 99% to 85% by weight of a solid diluent, such as an attaclay, kaolin, diatomaceous earth, fullers earth, talc, pumice or the like.

Dust concentrates are prepared in similar fashion to the dusts excepting that generally about 15% to about 95% by weight of active material is used.

Granular formulations may be prepared by applying a liquid solution of the active material to sorptive granular carriers, such as attaclay, kaolin, or diatomite granules. Alternatively, they may be mixed with inert carriers and applied to non-sorptive granules, such as sand or limestone.

Wettable powders are prepared by grinding the active ingredient with a solid carrier, such as used in the dust formulations. Usually, about 25% to 75% by weight of the active material and from about 73% to 23% by weight of solid carrier is used. In addition, there is generally added about 1% to 5% by weight of a dispersing agent, such as alkali metal salts of naphthalene sulfuric acid and anionic-nonionic blends, and from about 1% to 5% by weight of a surfactant, such as polyoxyethylene alcohols, acids, adducts, sorbitan fatty acid esters and sorbitol esters. Typical formulations by weight percent are given below.

TABLE I______________________________________ Typical Wettable Powder Formulations______________________________________A Ingredients______________________________________25% 4-(4-ethyl-.alpha.-methoxy-2,6-dinitro-m- tolyl)-2,6-dimethyl-morpholine65% attaclay5% sodium lignosulfonate5% sodium N-methyl-N-oleoyl taurate______________________________________B Ingredients______________________________________33% 1-(4-ethyl-.alpha.-methoxy-2,6-dinitro-m- tolyl)-pyrrolidine59% attaclay5% sodium lignosulfonate3% alkyl phenoxy polyoxyethylene ethanol______________________________________C Ingredients______________________________________40% 4-(2,6-dinitro-3,4-xylyl)morpholine50% precipitated hydrated silicon dioxide (Hi Sil).sup.a5 sodium lignosulfonate3% anionic-nonionic blend (MAL-77L).sup.b2% wetting agent______________________________________ .sup.a By Pittsburgh Plate Glass Company .sup.b By Wm. Cooper and Nephews

The wettable powder formulations are usually dispersed in water and applied as a liquid spray to the area or locus where control of undesirable plant species is desired.

For use as preemergence herbicides, the dusts or liquid sprays containing the active compound can be applied to the soil shortly after planting or they may be incorporated into the soil by the technique referred to as preplant incorporation.

The practice and advantages of the present invention and preparation of the active ingredients used therein is further illustrated by the following examples which are not to be taken as being limitative thereof. Parts and percentages herein are by weight unless otherwise indicated.

The following Examples 1-7 illustrate the preparation of the compound 4-(4-ethyl-.alpha.-methoxy-2,6-dinitro-m-tolyl)-2,6-dimethylmorpholine.

EXAMPLE 1

Preparation of .alpha.-chloro-2-ethyl-5-nitrotoluene

Paraformaldehyde (105.1 g) is added portionwise to a stirred solution of 620 ml. of concentrated sulfuric acid and 720 ml. of fuming sulfuric acid at 3.degree. C. to 10.degree. C. Anhydrous calcium chloride (252.5 g) is then added portionwise maintaining the temperature of the mixture between 4.degree. C. and 11.degree. C. The mixture is stirred in an ice bath for 1.5 hours and then treated dropwise with 260.0 g of 4-ethylnitrobenzene to maintain the reaction temperature between 6.degree. C. and 9.degree. C. The mixture is stirred between 9.degree. C. and 18.degree. C. for 13 hours and then between 18.degree. C. and 20.degree. C. for 123 hours. The mixture is poured into a slurry of ice and water and the crude product is extracted with chloroform. The chloroform layer is partially concentrated, shaken with 100 ml. of potassium bicarbonate, water, and stirred over magnesium sulfate. The filtered solution is concentrated under vacuum to yield 317.6 g of an amber liquid. The crude product is fractionated by vacuum distillation to yield a light yellow liquid with boiling point 114.degree. C. to 118.degree. C. at 0.2 mm. Hg.

EXAMPLE 2

Preparation of 2-ethyl-5-nitrobenzyl methyl ether

Sodium methoxide is added portionwise to a solution of 150.0 g of .alpha.-chloro-2-ethyl-5-nitrotoluene in 1.15 l. of methanol maintained between 18.degree. C. and 30.degree. C. The mixture is refluxed for 2 hours, cooled to 3.degree. C., and filtered. The filtrate is concentrated under vacuum and the resulting slurry shaken with saturated aqueous sodium chloride and methylene chloride. The methylene chloride layer is washed, filtered through sodium sulfate, and stirred over magnesium sulfate. The filtered solution is concentrated under vacuum to yield 133.89 g of a dark brown liquid. The crude product is fractionated by vacuum distillation to yield a yellow liquid with boiling point 113.degree. C. to 115.degree. C. at 0.35 mm Hg which solidifies to light yellow prisms with mp 21.5.degree. C. to 23.5.degree. C.

EXAMPLE 3

Preparation of 4-ethyl-N-(1-ethylpropyl)-.alpha.-methoxy-m-toluidine

A mixture of 10 g of 2-ethyl-5-nitro benzyl methyl ether, 10.38 g of 3-pentanone, 0.23 g of 2-naphthalene sulfonic acid, and 0.60 g of 5% platinum on carbon catalyst is shaken under hydrogen for 2 hours at room temperature and for 4 hours at 48.degree. C. to 60.degree. C. The mixture is diluted with 200 ml of ether, filtered and the filtrate shaken with 2.5% aqueous sodium hydroxide, washed with water, filtered through sodium sulfate and stirred over magnesium sulfate. The filtered solution is concentrated under vacuum to yield 10.76 g of an amber liquid, pure by glc and tlc analyses.

EXAMPLE 4

Preparation of 4-Ethyl-N-(1-ethylpropyl)-.alpha.-methoxy-2,6-dinitro-m-toluidine

A solution of 13.0 g of concentrated nitric acid, 10.75 g of concentrated sulfuric acid, and 4.88 g of water is added dropwise over a 2.3 hour period to a stirred solution of 7.75 g of 4-ethyl-N-(1-ethylpropyl)-.alpha.-methoxy-m-toluidine in 35 ml of 1,2-dichloroethane. The temperature of the mixture is maintained between 18.degree. C. and 21.degree. C. during the addition and for an additional 44 hours. The mixture is poured onto 30 g of ice and then extracted with methylene chloride. The extracts are combined with the dichloroethane layer, the combined organic layers washed with 2.5% aqueous sodium hydroxide and water and stirred over magnesium sulfate. The filtered solution is concentrated under vacuum to yield 10.86 g of a dark brown solid. Purification by chromatography yields yellow-orange crystals with mp 28.degree. C. to 29.degree. C.

EXAMPLE 5

Preparation of 4-ethyl-.alpha.-methoxy-2,6-dinitro-m-toluidine

The amine (100 g) is slowly added to 2 l. of 50% sulfuric acid with stirring and then warmed to 70.degree. C. for 22 hours. The reaction mixture is diluted with ice water, extracted with benzene and the benzene layer concentrated to an oily residue. The residue is taken up in CCl.sub.4 (100 ml) and poured with stirring into hexane (1.2 l.). The resulting solid after drying weighs 74 g (94% yield) and has mp 71.degree.-73.degree..

EXAMPLE 6

Preparation of 3-chloro-6-ethyl-2,4-dinitrobenzyl methyl ether

A solution of the aniline (40 g in 750 ml acetic acid) is added slowly with stirring to a solution of NaNO.sub.2 (17 g) in 136 ml sulfuric acid at 10.degree.-15.degree. C. After 30 minutes this reaction mixture is added to a solution of CuCl (37.8 g) in 480 ml hydrochloric acid with stirring. The product (25.0 g) precipitates from the cooled reaction mixture in 58% yield with mp 81.degree.-82.degree.. The filtrate upon dilution yields another 10 g of product.

EXAMPLE 7

Preparation of 4-(4-Ethyl-.alpha.-methoxy-2,6-dinitro-m-tolyl)-2,6-dimethylmorpholine

The benzyl ether (5 g) and 2,6-dimethylmorpholine (6.7 ml) are dissolved in toluene and heated under reflux for 24 hours. The reaction mixtue is washed with dilute hydrochloric acid, water and dried. After concentration the solid residue (4.9 g) is purified by chromatography on silica gel to give the product as a yellow solid with mp 84.degree.-86.degree. C.

Preparation of 1-(4-Ethyl-.alpha.-methoxy-2,6-dinitro-m-tolyl)-pyrrolidine

In a similar manner the subject compound is prepared using pyrrolidine in place of 2,6-dimethylmorpholine. The product is isolated as an orange solid with mp 49.degree.-50.degree. C.

EXAMPLE 8

Preparation of 3,4-Dimethyl-2,6-dinitrochlorobenzene

Two grams of 3,4-dimethyl-2,6-dinitroaniline [Chemical Abstracts 44: 4447 (1950] is dissolved in 40 ml. of warm glacial acetic acid. The solution is cooled to room temperature and a mixture of 0.9 grams of sodium nitrite in 7 ml. of concentrated sulfuric acid is added very slowly leaving a solid in the mixture. This mixture is then added to a solution of cuprous chloride in concentrated hydrochloric acid. The cuprous chloride solution is prepared by dissolving 3.24 grams of CuSO.sub.4.5H.sub.2 O in water and adding NaCl to the warm solution. While holding the blue solution in an ice bath, a solution of 1.24 grams of sodium meta-bisulfite and 0.52 grams of NaOH in 12 ml. of water is added. A white precipitate forms and is dissolved in 12 ml. of concentrated hydrochloric acid. The diazonium mixture is then warmed, filtered, and the solid collected and recrysatllized from cyclohexane. The product has a melting point of 109.degree. C. to 111.degree. C. The procedures are repeated using 16 grams of the amine, yielding 11 grams of product, having a melting point of 111.degree. C. to 113.degree. C.

EXAMPLE 9

Preparation of 3,4-Dimethyl-2,6-dinitrochlorobenzene

Fuming sulfuric acid (750 ml., 23%) and fuming nitric acid (240 ml., 90%) are mixed at 0.degree. C. to 45.degree. C. Then 4-chloro-o-xylene (270 grams, 1.93 moles) is added at 10.degree. C. to 60.degree. C. When the addition is complete, the reaction mixture is poured into 8000 ml. of ice and 4000 ml. water and then filtered. The cake is washed with 4000 ml. of water, 500 ml. methanol, and finally 500 ml. of petroleum ether. The cake is then slurried two times with 200 ml. xylene and filtered. The filter cake is then washed with 50 ml. cold xylene and 300 ml. of methanol at 50.degree. C. The solid is then recrystallized from 2500 ml. of methanol and washed with 2 pints of petroleum ether. The yield of white solid is 120 grams with melting point 112.degree. C. to 113.degree. C.

EXAMPLE 10

Preparation of 3,4-Dimethyl-2,6-dinitro-N,N-di-n-propylaniline

Five grams of 1-chloro-3,4-dimethyl-2,6-dinitrobenzene and 5.05 grams of di-n-propylamine are dissolved in benzene and the mixture is refluxed. The benzene is then removed from the mixture by boiling and toluene is added to the remaining residue. The thus-formed mixture is then refluxed, filtered, and the filtrate stripped in vacuo. The residue is treated with hexane and the mixture chilled in dry ice and acetone. The solid from the mixture is collected and dried, it has a melting point of 42.degree. C. to 43.5.degree. C. and is the desired product.

EXAMPLE 11

Preparation of N-Isopropyl-3,4-dimethyl-2,6-dinitroaniline

4-Chloro-3,5-dinitro-o-xylene (10.0 grams, 0.043 mole) and i-propylamine (10.1 grams, 0.17 mole) are mixed and refluxed for 12 hours using an efficient reflux condenser. The mixture is then cooled and poured into 100 ml. of 5% hydrochloric acid and extracted with diethyl ether. The ether extract is dried over magnesium sulfate. Removal of the drying agent and solvent leaves an orange oil which readily solidifies. The product is recrystallized from methanol to give 8.7 grams (80%) of an orange solid with melting point 69.degree. C. to 70.degree. C.

EXAMPLE 12

Preparation of N-sec-Butyl-3,4-dimethyl-2,6-dinitroaniline

A mixture of 4-chloro-3,5-dinitro-o-xylene (140 grams, 0.61 mole), mono-sec-butylamine (184 ml., 1.82 moles), and xylene (1400 ml.) is brought to reflux. After refluxing overnight, the reaction mixture is cooled and filtered. The precipitate is washed with petroleum ether. The filtrate and washings are combined, washed with 500 ml. of 10% hydrochloric acid, and finally with 2 liters of water. The organic layer is separated and dried. Removal of the drying agent and the solvent leaves an orange oil which crystallizes with the addition of petroleum ether. A yellow orange solid (150.6 grams, 86.5%) with melting point 42.degree. C. to 43.degree. C. is collected.

EXAMPLES 13 To 15

Following the general procedures of Example 7 and allowing the appropriate amine to react with the intermediate of Example 9, yields products having the following formula and properties set forth in Table II below.

______________________________________ ##STR6##TABLE II MeltingExample Substituents Point CrystallizingNumber R.sub.1 R.sub.2 .degree.C. Solvent______________________________________13 ##STR7## 118-119 methanol14 ##STR8## 106-108 cyclohexane15 ##STR9## 120-122 cyclohexane______________________________________

EXAMPLE 16

Preparation of N-(3-Hexyl)-4-allyl-3-methyl-2,6-dinitroaniline

One equivalent of 4-allyl-3-methyl-2,6-dinitrochlorobenzene is dissolved in three volumes of xylene containing two equivalents of 3-hexylamine. The mixture is refluxed for 5 hours and then poured into water. The organic phase is washed with 5% hydrochloric acid and then water, dried over calcium sulfate, and removed in vacuo to leave the above-named product.

EXAMPLE 17

Preparation of 4-Chloro-N-isopropyl-3-methyl-2,6-dinitroaniline ##STR10##

To a stirred mixture of 10.0 grams (0.04 mole) of 3,6-dichloro-2,4-dinitrotoluene in 50 ml. of ethanol is added 9.0 grams (0.15 mole) of isopropylamine. The mixture is stirred at room temperature for 2 hours and then at reflux for one hour. The solution is allowed to cool to room temperature and the crystalline precipitate is filtered and washed with a little hexane to give 10.2 grams of golden crystals, melting point 69.degree. C. to 73.degree. C. Two recrystallizations from methanol give the analytically pure compound, melting point 69.degree. C. to 70.degree. C.

EXAMPLE 18

Preparation of 4-Chloro-3-methyl-2,6-dinitro-N,N-dipropylaniline ##STR11##

A solution of 10.04 grams (0.04 mole) of 3,6-dichloro-2,4-dinitrotoluene, 12.2 grams (0.12 mole) of di-n-propylamine, and 60 ml. of toluene is stirred at reflux for 9 hours. The mixture is cooled, diluted with ether, and extracted twice with dilute hydrochloric acid. The organic phase is then extracted consecutively with water, aqueous sodium bicarbonate, and brine and dried over magnesium sulfate. Evaporation of the solvent at reduced pressure gives 12.5 grams of an oil. Crystallization of the product from hexane gives 9.08 grams of yellow solid, melting point 36.degree. C. to 38.degree. C. The analytically pure compound, melting point 41.degree. C. to 42.degree. C., is obtained by recrystallization from 95% ethanol.

EXAMPLES 19 TO 20

Following the general procedure of Example 18, substituting the appropriate amine for the di-n-propylamine used therein, yields compounds of the following structural formula having properties set forth in Table III below:

______________________________________ ##STR12##TABLE III MeltingExample Substituents Point CrystallizingNumber R.sub.1 R.sub.2 .degree.C. Solvent______________________________________19 ##STR13## 84-8720 ##STR14## 117-120.5______________________________________

example 21

preparation of Potassium 4-Chloro-3,5-dinitro-o-toluenesulfonate

m-Chlorotoluene (166 grams, 1.31 moles) is added to a mixture of 1000 ml. of concentrated sulfuric acid and 170 ml. of 23% fuming sulfuric acid and heated to 100.degree. C. The solution is then cooled to 25.degree. C. and potassium nitrate (400 grams) carefully added at 35.degree. C. to 45.degree. C. After the addition is complete, the reaction is stirred for one hour at 40.degree. C. to 45.degree. C. and then slowly heated to 100.degree. C. and held between 100.degree. C. and 110.degree. C. for 1.5 hours. Finally, the reaction mixture is cooled and poured into 12,000 ml. of ice and the precipitated solid collected. The product is washed with water and then recrystallized from 5 liters of water. The crude yield of potassium salt is 305 grams.

EXAMPLE 22

Preparation of 4-Chloro-3,5-dinitro-o-toluenesulfonyl Chloride

Sixty grams of potassium 4-chloro-3,5-dinitro-o-toluenesulfonate, 70 grams of phosphorus pentachloride and 120 ml. of phosphorus oxychloride are mixed and refluxed for 3 hours. The mixture is filtered to remove some insoluble solid. The filtrate is carefully poured into water at 20.degree. C. to 30.degree. C. The precipitated solid is collected and dissolved in 500 ml. of benzene. The benzene solution is washed with water and then dried over MgSO.sub.4. After removing the magnesium sulfate, the benzene is concentrated to 100 ml. and 400 ml. of hexane added. The precipitated solid is collected and recrystallized from 300 ml. hexane and 100 ml. of benzene to yield 50 grams of solid with melting point 105.degree. C. to 107.degree. C.

EXAMPLE 23

Preparation of 4-Chloro-3,5-dinitro-o-toluenesulfonamide

4-Chloro-3,5-dinitro-o-toluenesulfonamide

4-Chloro-3,5-dinitro-o-toluenesulfonyl chloride (10 grams, 0.0318 mole) is dissolved in 150 ml. of acetone and chilled to -15.degree. C. Ammonia (1.08 grams, 0.064 mole) is condensed and then vaporized into the acetone solution. When the addition is complete, the reaction mixture is poured into an equal volume of water and the precipitated solid collected. The crude yield of white solid is 6.8 grams with melting point 205.degree. C. to 215.degree. C.

EXAMPLE 24

Preparation of 3-Methyl-2,6-dinitro-N.sup.1,N.sup.1 -dipropylsulfanilamide

A mixture of 3.4 grams of 4-chloro-3,5-dinitro-o-toluenesulfonamide, N,N-dipropylamine (3.4 grams) and 50 ml. of toluene are brought to reflux. At this point, everything is in solution. After refluxing 24 hours, the mixture is cooled, washed with water, dilute acid and finally water. The organic layer is then separated and dried over MgSO.sub.4. Removal of the drying agent and solvent yields the desired product.

Following the general procedure of Example 25, substituting the appropriate amine and dinitrosulfonamide for N,N-dipropylamine and 4-chloro-3,5-dinitro-o-toluenesulfonamide, respectively, yields the products of the invention.

EXAMPLE 25

Preparation of N-sec-Butyl-3-methyl-2,6-dinitro-4-(trifluoromethyl)aniline

A nitration mixture, consisting of 16.1 ml. of H.sub.2 SO.sub.4 (d 1.84) and 1.9 ml. of HNO.sub.3 (d 1.5), is heated to 55.degree. C. and 3.5 grams of 5-chloro-2-(trifluoromethyl)toluene is slowly added. The mixture is heated for one hour at 55.degree. C. followed by one hour at 110.degree. C. The reaction mixture is cooled and poured onto ice to give 5-chloro-2-(trifluoromethyl)-4,5-dinitrotoluene as a cream-colored solid. The product is crystallized from cyclohexane to give 3.6 grams of cream-colored crystals, melting point 81.degree. C. to 82.degree. C. 1.8 Grams of 5-chloro-2-(trifluoromethyl)-4,6-dinitrotoluene is refluxed for 15 minutes with 3 ml. of mono-sec-butylamine and 30 ml. of benzene, cooled, filtered, washed with water until neutral, dried and vacuum stripped to give 1.5 grams of N-sec-butyl-3-methyl-2,6-dinitro-4-(trifluoromethyl)aniline as a yellow solid, melting point 38.degree. C. to 39.degree. C.

Following the general procedure of Example 26, substituting the appropriate amine for the mono-sec-butylamine used therein, yields compounds of the invention.

EXAMPLE 26

Preparation of 3,5-Dinitro-4-chloro-o-toluoyl Chloride

Ten grams of 3,5-dinitro-4-chloro-o-toluic acid is warmed on a water bath with 9.2 grams of phosphorus pentachloride and 30 ml. of benzene. After the solids dissolve, the benzene is distilled and the phosphorus oxychloride is removed under reduced pressure. The desired product as a residual oil solidifies on chilling.

EXAMPLE 27

Preparation of 3,5-Dinitro-4-chloro-o-toluamide

3,5-Dinitro-4-chloro-o-toluoyl chloride is treated with two equivalents of ammonia in cold acetone. The mixture is poured into water and the desired product as a precipitated solid collected by filtration.

EXAMPLE 28

Preparation of 3,5-Dinitro-4-chloro-o-toluonitrile

A finely powdered mixture of 15.5 grams (0.051 mole) of 3,5-dinitro-4-chloro-o-toluamide is heated with 12 grams (0.084 mole) of phosphorus pentoxide for 15 minutes at 300.degree. C. to 350.degree. C. The resulting nitrile is distilled from the reaction flask. Recrystallization of the solidified product from methanol gives the desired product as an analytically pure material.

EXAMPLE 29

Preparation of 4-Cyano-3-methyl-2,6-dinitro-N,N-dipropylaniline

A mixture of 4.82 grams of 3,5-dinitro-4-chloro-o-toluonitrile and 3 grams of di-n-propylamine in 25 ml. of toluene is refluxed 8 hours. The cooled mixture is then washed with water, dilute acid, and finally water. The organic layer is separated and dried over MgSO.sub.4. Removal of the drying agent by filtration and concentration of the filtrate in vacuo leaves a residual oil which when crystallized gives the product with melting point 97.degree. C. to 99.degree. C.

Compounds of the invention are prepared by above procedure by substituting the proper amine in Example 29.

The selective preemergence herbicidal activity of the compounds of the present invention is exemplified by the following Table IV in which the seeds of a variety of monocotyledonous and dicotyledonous plants are separately mixed with potting soil and planted on top of approximately one inch of soil in separate pint cups. After planting, the cups are sprayed with the selected aqueous-acetone solution containing test compound in sufficient quantity to provide the equivalent of about 0.25 to 4 pounds per acre of test compound per cup. The treated cups are then placed on greenhouse benches, watered and cared for in accordance with conventional greenhouse procedures. Three or four weeks after treatment, the tests are terminated and each cup is examined and rated according to the rating system set forth below. The herbicidal proficiency of the active ingredients of the present invention is evident from the test results which are reported in the tables below.

______________________________________Rating System % Difference in Growth fromRating System the Check*______________________________________0 - no effect 01 - possible effect 1-102 - slight effect 11-253 - moderate effect 26-405 - definite injury 41-606 - herbicidal effect 61-757 - good herbicidal effect 76-908 - approaching complete kill 91-999 - complete kill 1004 - abnormal growth, i.e., a definite phys- iological malformation but with an over- all effect less than a 5 on the rating scale.______________________________________Plant AbbreviationsSE - Sesbania TW - TeaweedMU - Mustard RI - RiceCR - Crabgrass BA - Barnyard grassVL - Velvet leaf GF - Green foxtailPI - Pigweed MG - Annual Morning gloryLA - Lambsquarters CO - CottonCN - Corn SB - SugarbeetsWO - Wild oats SY - SoybeanRG - Ragweed______________________________________ *Based on visual determination of stand, size, vigor, chlorosis, growth malformation and over-all plant appearance. Table IV__________________________________________________________________________Preemergence Herbicidal Evaluation of ##STR15## RateStructure lb/ Plant SpeciesR.sub.1 R.sub.2 Z Y Acre SE MU PI RG MG TW VL BA CR GF WO CN CO SY SB RI__________________________________________________________________________ ##STR16## CH.sub.3 CH.sub.3 4.0 2.0 1.0 0.50 0.25 8 7 0 0 0 0 0 0 0 0 0 0 0 0 0 9 6 3 0 0 7 2 1 1 0 5 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 0 0 0 0 0 0 0 0 0 0 0 0 ##STR17## CH.sub.3 CH.sub.3 10.0 4.0 2.0 1.0 0.50 0.25 9 9 0 0 0 0 0 0 4 3 3 3 0 0 8 7 0 0 0 0 0 9 8 5 0 0 0 9 9 8 6 0 0 9 8 7 2 1 0 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 ##STR18## CH.sub.3 CH.sub.3 4.0 2.0 1.0 0.50 0.25 5 3 0 0 0 7 0 0 0 0 2 0 0 0 0 9 5 2 0 0 9 9 7 5 2 9 8 7 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 2 0 0 0 0 0 0 ##STR19## CH.sub.3 Cl 4.0 0 3 1 0 5 0 0 5 0 0 0 ##STR20## CH.sub.3 CH.sub.3 4.0 2.0 1.0 0.50 0.25 5 2 0 0 0 2 0 0 0 0 1 0 0 0 0 6 2 0 0 0 9 8 7 5 2 8 7 5 2 0 0 0 0 0 0 7 2 3 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ##STR21## CH.sub.2 OCH.sub.3 C.sub.2 H.sub.5 1.0 0.50 0.25 0.13 0.06 0.03 2 0 0 0 0 2 2 0 0 8 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 1 0 0 0 0 1 0 0 0 0 0 9 9 8 5 0 0 9 9 9 9 2 0 9 9 9 5 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6 0 0 0 0 0 ##STR22## CH.sub.2 OCH.sub.3 C.sub.2 H.sub.5 1.0 0.50 0.25 0.13 0.06 0.03 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 9 8 7 2 0 0 9 9 9 8 6 2 9 9 8 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0__________________________________________________________________________ 0 *Average of two tests

Claims

1. A compound having the structure: ##STR23## wherein Y is CH.sub.3, C.sub.3 H.sub.7 -n, C.sub.3 H.sub.7 -i, C.sub.4 H.sub.9 -i, sec-C.sub.4 H.sub.9, Cl, CF.sub.3 or C.sub.2 H.sub.5, and

R.sub.1 and R.sub.2 taken together with the nitrogen ar morpholino or 2,6-dimethylmorpholino.

2. A compound according to claim 1: 4-(4-ethyl-.alpha.-methoxy-2,6-dinitro-m-tolyl)-2,6-dimethylmorpholine.