7-[3-(Trifluoromethyl)phenyl]pyrazolo[1,5-a]pyrimidine-3-carbonitrile → 4,5-Dihydro-7-[3-(trifluoromethyl)phenyl]pyrazolo[1,5-a]pyrimidine-3-carbonitrile

Beteiligte Stoffe

Reaktionsschritte

To a solution of 6.0 g of 7-(α,α,α-trifluoro-m-tolyl)pyrazolo[1,5-a]pyrimidine-3-carbonitrile (Ex. 3, U.S. Pat. No. 4,236,005) in 100 ml of glacial acetic acid, was added in portions, 3.0 g of sodium cyanoborohydride at room temperature under nitrogen. The mixture was stirred at room temperature for 2 hours. The precipitate was collected by filtration, washed with water, then dissolved in dichloromethane. The organic solution was neutralized with a saturated solution of sodium bicarbonate, then dried over anhydrous sodium sulfate and filtered. The filtrate was evaporated in vacuo and gave the desired product as a white solid. The product was recrystallized from isopropyl alcohol, mp 175°-177° C.

Herkunft & Nachweise