HERBICIDES

摘要

1323045 Derivatives of 2-acylaminothiazoles SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ NV 14 Jan 1971 [16 Jan 1970 20 April 1970] 1913/71 Heading C2C Novel thiazoles of the formula in which R and R1 are hydrogen or C 1-4 alkyl, R2 is C 2-8 alkyl, cycloalkyl of up to 8 carbon atoms, C 2-8 alkenyl or aryl (each of which may be substituted by F, Cl, Br, -CN or -CF 3 ), or R 2 is -NR3R4, where R3 is hydrogen, C 1-2 alkyl or R5CO- (where R5 is C 1-3 alkyl) and R4 is C 1-2 alkyl or R5CO-, n is 0, 1 or 2, and R6 is hydrogen (when n is 0), C 1-4 alkyl, cycloalkyl of up to 4 carbon atoms, or -NR7R8 (when n is 2) where R7 is hydrogen, C 1-4 alkyl, or cycloalkyl of up to 4 carbon atoms and R8 is as R7 or an alkali metal ion or R5CO-, or when R7 is H or alkyl R8 may be C 1-3 alkoxy or -NR9R10, where R9 and R10 are hydrogen or C 1-3 alkyl, or R7 and R8 together represent an alkylene radical, are prepared by reacting an amine of the formula with an acyl halide R2COX, or to obtain the ureas in which R3 is hydrogen, with an isocyanate R4NCO. The 5-thioethers, where n is 0, may be oxidized with chloroperbenzoic acid to the sulphoxides or with hydrogen peroxide to the sulphones. The 5-sulphamoyl derivatives may be obtained by chlorosulphonation of the 2-acylaminothiazoles and subsequent reaction with an amine R7R8NH. A large number of amides and ureas are specified. 2 - Amino - 5 - (ethyl- or methyl - thio)-thiazole is obtained by bromination of 2-aminothiazole and condensation of the resulting 2-amino-5- bromothiazole with ethyl or methyl mercaptan. The 4-methyl analogues are obtained similarly. The novel thiazoles possess herbicidal properties and are used in conventional forms as pre- and post-emergence weed-killers.