Patent ID: 6162943
Filing Date: 2000-12-19
Classification: C07C

Abstract:
Process for the preparation of .alpha.-alkoxy-.alpha.-trifluoromethyl-arylacetic esters of the formula (I) ##STR7## wherein R is selected from the group consisting of C.sub.1 -C.sub.6 -alkyl, C.sub.2 -C.sub.6 -alkenyl, C.sub.3 -C.sub.7 -cycloalkyl, C.sub.6 -C.sub.10 -aryl and C.sub.1 -C.sub.6 -halogenoalkyl,R' is selected from the group consisting of C.sub.1 -C.sub.4 -alkyl,X is selected from the group consisting of halogen, C.sub.1 -C.sub.4 -alkyl, C.sub.2 -C.sub.4 -alkenyl, C.sub.6 -C.sub.10 -aryl or C.sub.1 -C.sub.4 -alkoxy and nitro, andn is zero or an integer from 1 to 3;the process comprising the steps ofA) reacting (a) a keto ester of the formula (II) ##STR8## wherein R, X and n are as defined in formula (I), with (b) trifluoromethyl-trimethylsilane in the presence of (c) a solvent and (d) a fluoride that is at least slightly soluble in the reaction mixture as a catalyst to form a trimethyl silyl ether of the formula (III) ##STR9## wherein R, X and n are defined as in formula (I), B) reacting the trimethyl ether having formula (III) with an alkoxide, or an alcohol which has been rendered alkaline to give a salt of the compound of the formula (IV), ##STR10## wherein R, X and n are as defined in formula (I), and M.sup.+ is the ion of an alkali metal, andC) reacting the compound having the formula (IV) with an alkylating agent, to convert the O.sup.- M.sup.+ group into an OR' group.