Ozone-mediated nitration of benzoic acid, its alkali and alkaline-earth metal salts, ester, acid chloride, nitrile and amide with nitrogen dioxide

Abstract

The title compounds except for the amide are smoothly nitrated with nitrogen dioxide at low temperatures in the presence of ozone, giving a mixture of the corresponding nitro derivatives mainly composed of the meta isomer in high yield. The nitration products are generally rich in the ortho isomer compared with those obtained by the conventional procedures based on the use of nitric acid or mixed acid. Under similar conditions, benzamide readily loses nitrogen to afford benzoic acid and its nitro derivatives, while N,N-diethylbenzamide is converted into a mixture of three isomeric nitro derivatives with an approximate ratio ortho : meta : para= 3:3:4.