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

Participants

Reaction Steps

A 10.0 g amount of 7-[3-(trifluoromethyl)-phenyl]pyrazolo[1,5-a]pyrimidine-3-carboxamide (prepared as described in Example 1) was stirred under nitrogen as a suspension in 120 ml of glacial acetic acid (cooled in an ice bath) and then 5.5 g of sodium cyanoborohydride was added to the reaction mixture in portions with an additional 80 ml of glacial acetic acid. After one hour of stirring in the ice bath, the mixture was stirred at room temperature for 19 hours. The solution was evaporated to dryness, then water was added and the white precipitate which formed was collected by filtration and washed with an aqueous saturated solution of sodium bicarbonate, then with water. The solid was treated with 100 ml of acetonitrile, then was collected by filtration and dried to give 5.25 g of the desired product which was recrystallized from acetonitrile, m.p. 157°-160° C.

Provenance & Evidence