反应详情

0.01 moles of 2,6-dimethyl-3-ethyl-4-oxo-4H-pyrido[1,2-a]pyrimidine are dissolved in 20 ml. of acetone, 0.03 moles of methyl iodide are added and the mixture is kept in a bomb tube at 150° C. for 24 hours. The solution is evaporated to dryness, the residue is dissolved in 15 ml. of methanol and a solution of 0.05 moles of sodium tetrahydroborate (III) in 10 ml. of water is added. After 4 hours the methanol is distilled off and the aqueous phase is extracted with three 20-ml. portions of chloroform. The organic phase is dried, evaporated and added to the oily substance obtained are 10 ml. of ethanol saturated with hydrochloric acid. 1,2,6-trimethyl-3-ethyl-1,2,3,6,7,8,9,9a-octahydro-4-oxo-4H-pyrido[1,2-a]pyrimidine hydrochloride is obtained, which crystallizes when triturated with ether. The product obtained after recrystallization from a mixture of acetone and ether sublimates over 206° C. Yield: 41%.

1. customThe solution is evaporated to dryness
2. dissolutionthe residue is dissolved in 15 ml
3. distillationAfter 4 hours the methanol is distilled off
4. extractionthe aqueous phase is extracted with three 20-ml
5. customThe organic phase is dried
6. customevaporated
7. additionadded to the oily substance
8. customobtained