Patent ID: 6777575
Filing Date: 2004-08-17
Classification: C07C

Abstract:
A process for the preparation of a compound of formula (I): wherein R represents hydrogen or C1-6 alkyl; R1 represents C1-6 alkyl; R2 represents C1-6 haloalkyl, C1-6 alkyl, C1-6 haloalkoxy, C1-6 alkoxy, SOnR5 or halogen; R4 represents hydrogen, C1-6 haloalkoxy, C1-6 alkoxy, SOnR5 or halogen; or a 5 or 6-membered heterocyclic ring which may be unsaturated or partially saturated having 1 to 3 hetereo atoms selected from oxygen, nitrogen and sulphur, optionally substituted by halogen, C1-6 haloalkyl, C1-6 alkyl, C1-6 haloalkoxy, C1-6 alkoxy SOnR5, nitro or cyano; R5 represents C1-6 alkyl; and n represents 0, 1 or 2; or a salt thereof; which process comprises reacting a compound of formula (II): wherein R, R2 and R4 are as hereinbefore defined, and R3 represents nitro or a halogen atom selected from fluorine, chlorine and bromine; or a salt thereof, with a compound of formula (III): R1SXâ€ƒâ€ƒ(III) wherein R1 is as hereinbefore defined, and X represents hydrogen or an alkali metal; wherein the water content in the reaction mixture is less than 5 % by volume; wherein the process is performed under substantially anhydrous conditions; and wherein the process is carried out using at least one solvent selected from the group consisting of N-methylpyrrolidinone, acetonitrile, dimethyl-sulphoxide and combinations thereof.