反应详情

To a solution of 6-(2,4-dichloro-phenyl)-imidazo[1,2-a]pyridine-7-carbonitrile (3.07 g, 6.10 mmol, prepared according to Example 3, Step 2.3) in concentrated H2SO4 (55 mL) was added a freshly prepared mixture of fuming HNO3 in H2SO4 (1:2, v/v, 2.55 mL) at RT. The reaction mixture was stirred at RT for 2 h then cautiously added to cold water (300 mL) and extracted with DCM (5×). The combined organic fractions were dried over Na2SO4, filtered, and evaporated to dryness to give the crude 6-(2,4-dichloro-phenyl)-3-nitro-imidazo[1,2-a]pyridine-7-carbonitrile as a brown solid (533 mg). MS: 333 [M+1]+; HPLC: AtRet=1.57.

1. extractionextracted with DCM (5×)
2. dry with materialThe combined organic fractions were dried over Na2SO4
3. filtrationfiltered
4. customevaporated to dryness