反应详情

温度

100 °C

1.4 g of sodium are added in a fractionated way to 15 mL of MeOH. After total dissolution, 2.7 g of 5,5-dimethyl-1,4,5,6-tetrahydropyrimidin-2-amine solubilized beforehand in 5 mL of MeOH, and then 16.5 mL of ethyl malonate are added. The mixture is heated to 100° C., after 4 h of heating, the medium is dry concentrated. The obtained oil is taken up in ether. The precipitate is filtered and then the residue is taken up in 7 mL of H2O and acidified with conc. HCl up to pH 3-4. The precipitate formed is filtered, washed with ether and dried in the oven in vacuo. 2 g (yield=72%) of 2-hydroxy-7,7-dimethyl-6,7,8,9-tetrahydro-4H-pyrimido[1,2-a]pyrimidin-4-one are obtained as a beige solid used as such.

1. temperatureof heating
2. customthe medium is dry
3. concentrationconcentrated
4. filtrationThe precipitate is filtered
5. customThe precipitate formed
6. filtrationis filtered
7. washwashed with ether
8. customdried in the oven in vacuo