34165-09-8

General procedure for the synthesis of 2-methyl-3-nitroimidazo[1,2-a]pyridine from 2-methylimidazo[1,2-a]pyridine: to a cooled solution of 2-methylimidazo[1,2-a]pyridine (380 mg, 2.88 mmol) in concentrated sulfuric acid (6 mL) was slowly added nitric acid (472 μL, density = 1.38 g/mL) dropwise. The reaction mixture was stirred for 2 h at room temperature and then cooled in an ice bath, followed by slow addition of saturated aqueous Na2CO3 solution adjusted to alkaline. The reaction mixture was extracted with dichloromethane (CH2Cl2) and the organic layer was dried with anhydrous magnesium sulfate (MgSO4), filtered and concentrated under reduced pressure to give 330 mg (1.82 mmol, 65% yield) of 2-methyl-3-nitroimidazo[1,2-a]pyridine as a brown solid.LRMS (m/z): 178 ([M+H]+).

[1] Bioorganic and Medicinal Chemistry, 2013, vol. 21, # 22, p. 7155 - 7164
[2] Patent: EP2848615, 2015, A1. Location in patent: Paragraph 0099
[3] Chemical and Pharmaceutical Bulletin, 2001, vol. 49, # 12, p. 1631 - 1635