Process for the preparation of substituted 3,5- dichloro-2,4-difluoro-benzenes

Abstract From the Canadian patent

Process for the preparation of substituted 3,5-dichloro-2,4-difluoro-benzenes, A b s t r a c t Substituted 3,5-dichloro-2,4-difluoro-benzenes of the formula, (1), in which, R represents nitro amino (including the corres-, ponding ammonium salts) or isocyanato which can be prepared from 2,3,4,5-tetrachloro-nitrobenzene by means of the reaction, carried out initially with alk-, ali metal fluorides at elevated temperature in a polar aprotic solvent, starting from a crude 2,3,4,5-tetrachloronitrobenzene containing 2,3,5,6-tetrachloro-nitrobenzene and/or 2,3,4,6-tetrachloro-nitrobenzene and substituted, 3,5-dichloro-2,4-difluoro-benzene being isolated from the reaction mixture at the nitro stage …