反应详情

A mixture containing 1.22 g (0.006 mol) of 7-methyl-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxylic acid and 0.84 ml (0.006 mol) of triethylamine in 40 ml of chloroform is cooled below -10° C. by ice-salt. A solution of 0.46 ml (0.006 mol) of methyl chloroformate in 3 ml of chloroform is dropped to the above mixture at -18° C. during 10 minutes. After stirring for 5 minutes, 0.56 g (0.0066 mol) of cyclopentylamine dissolved in 6 ml of chloroform is dropped to the above solution which is then stirred at -10° C. for 1 hour and allowed to stand overnight under cooling by ice. For working up, the reaction mixture is washed 3 times with 15 ml of 5% sodium hydrogen carbonate solution each, then 3 times with 15 ml of water each. The organic phase is dried over anhydrous sodium sulfate, filtered and evaporated to give 0.8 g (49.2%) of the named compound as white crystals after recrystallization from ethanol, m.p.: 162°-164° C.

1. additionis dropped to the above solution which
2. stirringis then stirred at -10° C. for 1 hour
3. waitto stand overnight
4. temperatureunder cooling by ice
5. washthe reaction mixture is washed 3 times with 15 ml of 5% sodium hydrogen carbonate solution each, then 3 times with 15 ml of water each
6. dry with materialThe organic phase is dried over anhydrous sodium sulfate
7. filtrationfiltered
8. customevaporated