2,3-Difluoro-6-nitrobenzonitrile and 2-chloro-5,6-difluorobenzonitrile, processes for their manufacture and use in the manufacture of 2,3,6-trifluorobenzoic acid

摘要

The present invention describes the novel intermediates 2,3-difluoro-6-nitrobenzonitrile and 2-chloro-5,6-difluorobenzonitrile, a process for their preparation, and their advantageous use for the preparation of 2,3,6-trifluorobenzoic acid which, in turn, is a valuable intermediate for the preparation of insecticides and antibacterial agents. The intermediates according to the invention can successfully be prepared starting with 2,3,4-trifluoronitrobenzene by fluorine/cyanide exchange followed by denitrating chlorination. 2,3,6-Trifluorobenzoic acid can be prepared from the novel intermediates in a manner known per se from the literature by simple chlorine/fluorine exchange followed by hydrolysis, in a process which is generally technologically advantageous and economically favourable.