PROCESS FOR THE PREPARATION OF O-CHLOROMETHYL-PHENYLGLYOXYLIC ACID DERIVATIVES

摘要

There is described a process for the preparation of a compound of formula I <IMG> in which process: a) a compound of formula II <IMG> is reacted with an organolithium compound of formula III Li-R7 (III) b) the resulting lithium complex is reacted with a compound of formula IV Y1-CO-CO-Y1 IV to form a compound of formula V <IMG> c) that compound is, in either order, c1) oximated with O-methylhydroxylamine; or oximated with hydroxylamine and then methylated or fluoromethylated or difluoromethylated; c2) reacted with a chloroformic acid ester. X, m, Y, R1 to R3 and R7 are as defined in the description.