GB951651A - Substituted benzonitriles, their preparation and compositions containing them - Google Patents

Abstract

The invention relates to benzonitrile derivatives of the formula: <FORM:0951651/C2/1> in which X is a chlorine or bromine atom, Z is an oxygen or sulphur atom or a sulphinyl (SO) or sulphonyl (SO2) group and R is a hydrocarbon group which may be substituted by halogen or by a trifluoromethyl, nitro, amino, acylamino, hydroxy, hydrocarbyloxy, carboxy or hydrocarbyloxycarbonyl group or by a group -OCH2CH2OR1, in which R1 is a hydrogen atom or an alkyl group of 1-4 carbon atoms. The compounds are prepared by treating 2-chloro-or 2-bromo-6-nitrobenzonitrile with a compound of the formula MZ1R, in which M is an alkali metal or ammonium and Z1 is oxygen or sulphur, or with a mixture of a compound HZ1R and an alkali-metal hydroxide or hydride or ammonia or ammonium hydroxide; if Z in the formula above is to be a sulphinyl group, the resulting thio derivative is then oxidized or, if Z is to be a sulphonyl group, the thio or the sulphinyl derivative is oxidized. In typical examples, 2-chloro-6-nitrobenzonitrile is reacted (1) with phenol and sodium methoxide to yield 2-chloro-6-phenoxybenzonitrile, (2) with p-methoxyphenol and sodium hydride to yield 2-chloro -6- (4-methoxy phenoxy) benzonitrile, (3) with sodium 3-methoxycarbonylphenoxide to yield 2-chloro -6- (3-methoxycarbonylphenoxy) benzonitrile, (4) with 1-naphthol and sodium hydride to yield 2-chloro -6- (1-naphthyloxy) benzonitrile, (5) with methanol and potassium hydroxide to yield 2-chloro-6-methoxybenzonitrile, (6) with thiophenol and sodium hydride to yield 2-chloro -6- phenylthiobenzonitrile, (7) with allyl thiol and sodium hydride to yield 2-chloro-(6-allylthio)benzonitrile, and (8) ethyl thioglycollate sodium salt and sodium hydride to yield 2-chloro -6- (ethoxycarbonylmethylthio) benzonitrile. The reactions may be effected at 120-250 DEG C., preferably in a solvent, a number of which are specified. Examples are given also in which 2-chloro -6- phenylthiobenzonitrile is oxidized to the corresponding sulphinyl compound with hydrogen peroxide and acetic acid and to the corresponding sulphonyl compound with a larger proportion of hydrogen peroxide. Other examples describe the preparation of 2-chloro-6-(2, 4-dichlorophenoxy) benzonitrile, 2-chloro-6-(3-nitrophenoxy) benzonitrile, 2-chloro -6- (2-and 3-methoxy phenoxy) benzonitrile, 2-chloro-6-(3-trifluoromethylphenoxy) benzonitrile, 2-chloro -6- (3-carboxyphenoxy) benzonitrile, 2-chloro -6- (4-aminophenoxy) benzonitrile, 2-chloro -6- (4-acetylaminophenoxy) benzonitrile, 2-chloro -6- (2- and 4-chlorophenoxy) benzonitrile, 2-chloro -6- (3- and 4-tolyloxy) benzonitrile, 2-chloro -6- (2-naphthyloxy) benzonitrile, 2-chloro -6- allyloxybenzonitrile, 2-chloro -6-isopropoxy- and -6- isobutoxybenzonitrile, 2-chloro -6- (2-methoxyethoxy) benzonitrile, 2-chloro -6- (2-hydroxyethoxy) benzonitrile, 2-chloro -6- benzyloxybenzonitrile, 2-chloro -6-(4-tolylthio) benzonitrile, 2-chloro -6- (4-chlorophenylthio) benzonitrile, 2-chloro -6- (benzylthio) benzonitrile, 2-chloro -6- (4-chlorobenzylthio) benzonitrile, 2-chloro -6- ethylsulphonylbenzonitrile and 2-chloro -6- (4-chlorobenzylsulphonyl) benzonitrile. Other radicals R are also specified. Apart from 2-chloro -6- methoxybenzonitrile, the products are claimed as new compounds. The products are useful as herbicides, some being toxic to plant seeds and some to growing plants when applied as a foliar spray or as a soil drench. 2-chloro -6- allylthiobenzonitrile, 2-chloro -6- (3-nitrophenoxy) benzonitrile and 2-chloro -6- (3-tolyloxy) benzonitrile are useful also as fungicides. 2-Chloro -6- (3-tolyloxy) benzonitrile is useful also as an insecticide. 2-Chloro -6- (2, 4-dichlorophenyl) benzonitrile and 2-chloro -6- (3-tolyloxy) benzonitrile are useful also for combatting aquatic snails which are carriers for bilharziasis. For all these purposes the products may be prepared as solid compositions, wettable powders, dusts, emulsions, solutions or emulsifiable concentrates with the aid of solid or liquid carriers and (or) surface-active agents, a number of each of which are specified. Experimental results of the application of some of the products are given. Specification 861,898 is referred to.ALSO:Herbicidal and pesticidal compositions comprise benzonitrile derivatives of the formula <FORM:0951651/A5-A6/1> in which X is a chlorine or bromine atom, Z is an oxygen or sulphur atom or a sulphinyl (SO) or sulphonyl (SO2) group and R is a hydrocarbon group which may be substituted by halogen or by a trifluoromethyl, nitro, amino, acylamino, hydroxy, hydrocarbyloxy, carboxy or hydrocarbyloxycarbonyl group or by a group -OCH2CH2OR1, in which R1 is a hydrogen atom or an alkyl group of 1-4 carbon atoms (see Division C2). The products are applied as a foliar spray or as a soil drench. 2 - Chloro - 6 - allylthiobenzonitrile, 2 - chloro-6 - (3 - nitrophenoxy)benzonitrile and 2 - chloro - 6 - (3 - tolyloxy)benzonitrile are useful also as fungicides. 2-Chloro-6-(3-tolyloxy) benzonitrile is useful also as an insecticide. 2 - Chloro - 6 - (2,4 - dichlorophenyl)benzonitrile and 2 - chloro - 6 - (3 - tolyloxy)benzonitrile are useful also for combating aquatio snails which are carriers for bilharziasis. For all these purposes the products may be prepared as solid compositions, wettable powders, dusts, emulsions, solutions or emulsifiable concentrates with the aid of solid or liquid carriers and (or) surface-active agents, a number of each of which are specified. Experimental results of the application of some of the products are given.