Preparation of 3,5-dinitrobenzoic acid from meta-nitrobenzoic acid

@article{Lebedev2004PreparationO3,
  title={Preparation of 3,5-dinitrobenzoic acid from meta-nitrobenzoic acid},
  author={B. A. Lebedev and Valerii Yu. Dolmatov and P. S. Zubarev and N. V. Latynov and M. M. Aleksandrov and R. I. Ponamareva},
  journal={Pharmaceutical Chemistry Journal},
  year={2004},
  volume={22},
  pages={399-401}
}
The two methods known for obtaining 3,5-DNBA are by the oxidation of 3,5-dinitrotoluene [7] and 1,5-dinitronaphthalene [2], and by the nitration of benzoic or meta-nitrobenzoic acids [i, 4, 5, 8]. The disadvantages of these methods of obtaining 3,5-DNBA are related to the inordinately high proportion of acid (20-60 parts by weight), the low yield (6-50%), and the presence of major impurities, including isomers of dinitrobenzoic acid, mononitrobenzoic acid, and products from the partial…