Imidazole → HCID 20735492, compound

Participants

Reaction Steps

To a solution of the pyrazole of Example 89 (3.0 g, 9.6 mmol) in dimethylformamide (20 ml) was added imidazole (850 mg, 12.5 mmol), followed by tert-butyldimethylchlorosilane (1.58 g, 10.6 mmol). The solution was stirred at room temperature for 20 hours. The reaction mixture was partitioned between diethyl ether and aqueous sodium carbonate and the aqueous phase was separated and further extracted with diethyl ether. The combined organic phases were washed with water, washed with brine, dried over anhydrous magnesium sulphate, filtered and evaporated under reduced pressure. The crude product was purified by flash chromatography on silica gel eluting with dichloromethane:methanol:ammonia (95:5:0.5, by volume) to afford the title compound (4.0 g) as a colourless oil.

Provenance & Evidence