GB1141183A - Aliphatic mercaptoanilides and their use as herbicides - Google Patents

Abstract

1,141,183. Aliphatic mercaptoanilides. FARBENFABRIKEN BAYER A.G. 8 Aug., 1967 [9 Sept., 1966; 9 March, 1967; 11 April, 1967], No. 36371/67. Heading C2C. [Also in Division A5] The invention comprises aliphatic mercaptoanilides of the formula in which R 1 denotes an aliphatic hydrocarbon radical of 1-8 carbon atoms which may be substituted by halogen atoms and (or) hydroxy, alkoxy, carboxy, phenoxy or hydroxyphenoxy groups, R 2 denotes (a) an aliphatic hydrocarbon radical of 1-9 carbon atoms, which may be substituted by halogen atoms or hydroxy and (or) alkoxy groups or (b) a cyclopropyl, cyclobutyl or alkoxycyclopropyl group, R 3 denotes hydrogen or an alkyl group of 1-3 carbon atoms, X 1 denotes a hydrogen or halogen atom, an alkyl or alkoxy group of 1-4 carbon atoms or a haloalkyl group and X 2 denotes a hydrogen or halogen atom or a methyl or ethyl group. Many specific instances of the radicals R 1 and R 2 are given, including some alkyl, alkenyl or alkinyl groups which may carry substituents, as specified above. The compounds may be prepared (a) by reacting an arylamine of the formula with an appropriate carboxylic acid halide in the presence of a solvent and an acid-binding agent, or (b) by reacting an arylamine as defined above with an appropriate carboxylic anhydride, or (c) by reacting an arylamine as defined above with an ester of an appropriate carboxylic acid and an alcohol of 1-6 carbon atoms or phenol, or (d) by reacting an isocyanate of the formula with an appropriate carboxylic acid, carbon dioxide being split off, or (e) by reacting an arylalkyl ketone of the formula with hydroxylamine to yield the corresponding oxime, which is then subjected to the Beckmann re-arrangement. Method (d) is not applicable to the preparation of alkylmercaptoanilines which contain a carboxylic or hydroxy group in the side chain or which are alkylated on the nitrogen atom, and method (e) is applicable only when R 2 in the first formula above denotes an alkyl radical of 1-9 carbon atoms. Numerous examples are given. The products are useful as herbicides (see Division A5). 3 - Chloro - 4 - allylmercaptoaniline, an intermediate in the process, is prepared by treating 3,4 - dichloronitrobenzene with sodium sulphide to yield 2 - chloro - 4 - aminothiophenolate, which is then reacted with allyl chloride. A number of other intermediates obtained similarly from p-chloronitrobenzenes are listed.