反应详情

A 6.0 g amount of 7-phenylpyrazolo[1,5-a]-pyrimidine-3-carboxamide (prepared as described in Example 2) was stirred under nitrogen as a suspension in 120 ml of glacial acetic acid (cooled in an ice bath) and then 3.5 g of sodium cyanoborohydride was added to the reaction mixture in portions. After one hour of stirring in the ice bath, the mixture was stirred at room temperature for 3.5 hours at which time the original solid dissolved. Stirring was continued for one hour longer then the solution was concentrated in vacuo. Water was added to the residue and a precipitate formed. The precipitate was collected by filtration and then was dissolved in dichloromethane. The organic solution was washed with a saturated solution of sodium bicarbonate, dried over anhydrous sodium sulfate and filtered. The filtrate was evaporated in vacuo to give a solid. The solid was recrystallized from isopropyl alcohol to give 5.0 g of the desired product as a white solid, m.p. 149°-152° C.

1. dissolutiondissolved
2. stirringStirring
3. waitwas continued for one hour
4. concentrationlonger then the solution was concentrated in vacuo
5. additionWater was added to the residue
6. customa precipitate formed
7. filtrationThe precipitate was collected by filtration
8. dissolutionwas dissolved in dichloromethane
9. washThe organic solution was washed with a saturated solution of sodium bicarbonate
10. dry with materialdried over anhydrous sodium sulfate
11. filtrationfiltered
12. customThe filtrate was evaporated in vacuo
13. customto give a solid
14. customThe solid was recrystallized from isopropyl alcohol