Patent ID: 7291729

Claim:
A process for the preparation of a compound according to formula V wherein R 2 is an aryl radical optionally substituted with one to three substituents independently selected from the group consisting of C 1-6 alkyl, C 1-6 alkenyl, C 1-6 haloalkyl, C 3-8 cycloalkyl, C 1-6 alkoxy, C 1-6 alkylthio, C 1-6 alkylsulfinyl, C 1-6 sulfonyl, C 1-6 haloalkoxy, C 1-6 haloalkylthio, hydroxy, halogen, amino, C 1-6 alkylamino, C 1-6 dialkylamino, aminoacyl, acyl, C 1-6 alkoxycarbonyl, carbamoyl, C 1-6 N-alkylcarbamoyl, C 1-6 N,N-dialkylcarbamoyl, nitro and cyano; R 4a in each occurence is independently hydrogen C 1-6 alkyl, tert-butyl or benzyl; comprising the steps of; (i) contacting an alkali metal aryloxide II with 2,3,4-trifluoronitrobenzene in a first solvent at temperatures from about −30° C. up to about 40° C. to afford a 3,4-difluoro-2-aryloxynitrobenzene compound III as shown in the following reaction; (ii) further contacting said 3,4-difluoro-2-aryloxynitrobenzene compound III with an alkali metal salt of a malonate diester IV in a second solvent at a temperature of at least about −20° C. up to about 40° C. to afford a 2-fluoro-3-phenoxyphenylacetic ester V as shown in the following reaction