反应详情

A mixture containing 16.32 g (0.08 mol) of 6-methyl-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxylic acid and 12.4 ml (0.088 mol) of triethylamine in 480 ml of chloroform is cooled below -10° C. by ice-salt. A solution of 6.5 ml (0.08 mol) of methyl chloroformate in 40 ml of chloroform is dropped to the above mixture at -20° C. during 20 minutes. After stirring for 5 minutes, 6.47 g (0.088 mol) of tert.-butylamine dissolved in 80 ml of chloroform are dropped to the above solution at a temperature between -18° C. and -20° C. during 50 minutes. The reaction mixture is stirred for 1 hour at the same temperature and then let to stand in the refrigerator overnight. For working up, the mixture is washed 3 times with 150 ml of 5% sodium hydrogen carbonate each and then 3 times with 150 ml of water each. The organic phase is dried over anhydrous sodium sulfate and evaporated to give 15.5 g (74.7%) of the named product as light beige crystals after recrystallization from ethanol, m.p.: 164°-166° C.

1. additionare dropped to the above solution at a temperature between -18° C. and -20° C. during 50 minutes
2. stirringThe reaction mixture is stirred for 1 hour at the same temperature
3. customto stand in the refrigerator overnight
4. washthe mixture is washed 3 times with 150 ml of 5% sodium hydrogen carbonate each and then 3 times with 150 ml of water each
5. dry with materialThe organic phase is dried over anhydrous sodium sulfate
6. customevaporated