Methyl chloroformate → 4H-Pyrido(1,2-a)pyrimidine-3-carboxamide, N-(2,2-dimethylpropyl)-6-methyl-4-oxo-

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Reaction Steps

A mixture containing 8.16 g (0.04 mole) of 6-methyl-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxylic acid and 6.2 ml (0.044 mol) of triethylamine in 240 ml of chloroform is cooled below -10° C. by ice-salt. A solution of 3.25 ml (0.04 mol) of methyl chloroformate in 20 ml of chloroform is dropped to the above solution at -16° C. during 10 minutes. After stirring for 5 minutes, 3.83 g (0.044 mol) of neopentylamine dissolved in 10 ml of chloroform are dropped to the above solution at -10° C. during 5 minutes. After stirring at -10° C. for 1 hour, the reaction mixture is washed 3 times with 80 ml of 5% sodium hydrogen carbonate solution each and then 3 times with 80 ml of water each. The organic phase is dried over anhydrous sodium sulfate and then evaporated to give 6.8 g (62.2%) of the named product as yellow crystals after recrystallization from ethanol, m.p.: 191°-194° C.

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