2-Propen-1-one, 3-(dimethylamino)-1-(4-pyridinyl)- → 2-(4-Phenylmethyl-1-piperazinyl)-7-(4-pyridyl)pyrazolo[1,5-a]pyrimidine-3-carbonitrile

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Reaction Steps

A mixture of 2.2 g of 3-amino-5-(4-phenylmethyl-1-piperazinyl)-4-pyrazolecarbonitrile (Example 1) and 1.37 g of 3-dimethylamino-1-(4-pyridyl)-2-propen-1-one U.S. Pat. No. 4,281,000, Example 63) in 25 ml of glacial acetic acid was refluxed for 6 hours. The solution was taken to dryness in vacuo. The residue was partitioned between saturated sodium bicarbonate and dichloromethane (1:2). The dichloromethane layer was separated, dried over anhydrous sodium sulfate and filtered through a short column of magnesium silicate. The effluent was refluxed on a steam bath with the gradual addition of hexane until turbidity was noted. After cooling, the precipitate was collected by filtration. The solid was recrystallized from dichloromethane/hexane and gave 1.65 g of the product of the Example as very pale yellow crystals, mp 193°-194° C.

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