On the Synthesis of 2-Amino-4,6-difluorobenzonitrile: Highly Selective Formation of 5-Fluoro-3-nitro-1,2-benzoquinone 2-Diazide in the Attempted Sandmeyer Cyanation of 2,4-Difluoro-6-nitrobenzenediazonium Cation†

Abstract

Attempted cyanation of a diazonium salt derived from 2,4-difluoro-6-nitroaniline gives 5-fluoro-3-nitro-1,2-benzoquinone 2-diazide‡ in good yield by selective nucleophilic substitution of the 2-fluoride group by hydroxide, instead of the desired 2-amino-4,6-difluorobenzonitrile, which can be obtained by the reaction of 2,4,6-trifluorobenzonitrile with ammonia.