Process for preparation of? Acid 4-nitro-oxy-methyl-benzoic acid.

Process for preparation of acid 4-nitro-oxy-methyl-benzoic acid. The present invention relates to a novel process for preparing acid 4-nitro-oxy-methyl-benzoic acid, comprising the following steps: a) reacting 4-chloromethyl-benzoic acid with silver nitrate in the presence of an acid catalyst in acetonitrile at reflux temperature, followed by cooling and addition of an aprotic polar solvent; b) separation of the silver salts by filtration, followed by washing with a polar aprotic solvent; c) precipitating the acid 4-nitro-oxy-methyl-benzoic acid with water from the filtrate of step b); Y d) drying the acid 4-nitro-oxy-methyl-benzoic acid.