Ethanol → 2-Furanyl(7-phenylpyrazolo[1,5-a]pyrimidin-3-yl)methanone

Participants

Reaction Steps

A mixture of 0.86 g of (3-amino-1H-pyrazol-4-yl)-2-furanylmethanone and 0.63 g of 1-phenyl-1-propynone in 25 ml of ethanol with a catalytic amount of p-toluenesulfonic acid was heated on a steam bath for 1.5 hours. The mixture was chilled and then filtered giving 1.0 g of yellow solid. This solid was dissolved in a small amount of dichloromethane and placed on a silica gel column. The column was eluted with ethyl acetate:hexane (1:20) with a gradual change to ethyl acetate:hexane (2:5) as eluent. The column was then washed with ethyl acetate and the ethyl acetate wash was concentrated to a solid. This solid was cyrstallized from dichloromethane, giving 0.85 g of the desired product as cream crystals having a melting point of 188°-190° C. and a pmr spectrum identical to that of the product prepared as described in Example 22.

Provenance & Evidence