16013-85-7

yellow crystalline powder or chunks

Nitropyridine nucleus played a pivotal role in the development of different medicinal agents and in the field of agrochemicals. It is seen from the current literature that pyridine derivatives have been developed and used as insecticidal agents. Nitrated pyridines and their derivatives are important intermediates in synthesis of heterocyclic compounds in dyes and pharmaceutical products. Fused heterocycles containing nitropyridine systems have been associated with several biological and medicinal activities including antiolytic, antiviral and anti-inflammatory profiles.

General procedure for the synthesis of 2,6-dichloro-3-nitropyridine from 2,6-dichloropyridine: 80 mL of concentrated sulfuric acid was added to a 150 mL three-necked flask with stirring at room temperature, and 7.4 g (0.05 mol) of 2,6-dichloropyridine (IV) was slowly added, followed by the slow addition of 10.1 g (0.1 mol) of potassium nitrate. After the addition was completed, stirring was continued for 30 minutes, then the temperature was slowly increased to 120°C and the reaction was maintained at this temperature for 10 hours. Upon completion of the reaction, the reaction mixture was cooled to room temperature and poured into crushed ice with stirring. The precipitated white solid precipitate was washed to neutrality with ice water, immediately subjected to diafiltration, and dried to give 7.75 g of white solid 2,6-dichloro-3-nitropyridine (V) in 80% yield and melting point of 61-63 °C.

The asymmetric unit of 2,6-Dichloro-3-nitropyridine consists of two crystallographically independent mol-ecules. The pyridine ring in each mol-ecule is essentially planar, with maximum deviations of 0.004 (4) and 0.007 (4)Å. Short Cl-O [3.09?(3) and 3.13 (4)Å] and Cl-Cl [3.38 (12)Å] contacts were observed. No significant inter-molecular inter-actions were observed in the crystal packing.

[1] Patent: CN103936766, 2016, B. Location in patent: Paragraph 0032-0033
[2] Patent: US2006/80790, 2006, A1. Location in patent: Page/Page column 2
[3] Patent: WO2017/31176, 2017, A1. Location in patent: Page/Page column 33-34
[4] Journal of Heterocyclic Chemistry, 1984, vol. 21, # 5, p. 1521 - 1525
[5] ChemMedChem, 2015, vol. 10, # 2, p. 368 - 379