2,3-difluoro-6-nitrobenzonitrile, 2-chloro-5,6- difluorobenzonitrile (2,3-difluoro-6-chlorobenzonitrile), their production and method of using them to produce 2,3,6-trifluorobenzoic acid

PURPOSE: To obtain a new compound valuable as an intermediate for the preparation of bactericides and antibacterial agents. CONSTITUTION: A 2,3-difluoro-6-nitrobenzonitrile and a 2,3-difluoro-6- chlorobenzonitrile represented by formula (R is NO 2 or Cl). The compounds are obtained by reacting a 2,3,4-trifluoronitrobenzene with 1.0 to 5 molar times, favorably 1.1 to 3 molar times of cyanide in the presence of a solvent at 20 to 120°C, favorably 40 to 80°C to form a compound in which R is NO 2 and optionally, subsequently reacting it with a chlorinating agent (e.g. chlorine or phosphorus trichloride) in the presence of a fluoride-capturing agent and/or dehydrating agent at 160 to 200°C, favorably 170 to 190°C to form a compound in which R is Cl. A 2,3,6-trifluorobenzoic acid is prepared by reacting the compound of formula in which R is Cl with a fluoride and hydrolyzing the resulting 2,3,6-trifluorobenzonitrile. COPYRIGHT: (C)1995,JPO