Ethyl Acetate → 1-formyl-2,3-dihydro-1H-imidazo[1,2-b]pyrazole

Participants

Reaction Steps

To a solution of 1-(2-methylsulfonyloxyethyl)-5-formamidopyrazole (6.2 g) in N,N-dimethylformamide (60 ml) was added 62% sodium hydride (1.03 g) under ice-cooling. The mixture was stirred at the same condition for 3 hours. The reaction mixture was poured into ethyl acetate (300 ml) and the insoluble material was filtered off. The filtrate was evaporated under reduced pressure and the residue was subjected to column chromatography on silica gel (100 g) using a mixture of diisopropyl ether and ethyl acetate as an eluent. Fractions containing the object compound were combined and evaporated in vacuo to give 1-formyl-2,3-dihydro-1H-imidazo[1,2-b]pyrazole (3.91 g) as crystals.

Provenance & Evidence