反应详情

A mixture of 9,10-dimethoxy-3,4,6,7-tetrahydro-2H-pyrimido(6,1-a)isoquinolin-2,4-dione (4.11 g), oil-free sodium hydride (0.75 g) and dimethylformamide (100 ml) is heated for 15 minutes to 100° C. and then cooled to room temperature. Methyl iodide (10 ml) is added and the reaction mixture is heated for 12 hours to 100° C. The solvent is removed under reduced pressure and the residue treated with cold water. The solid matter is filtered off and recrystallized from ethyl acetate/methylene chloride. Yield 4.0 g, melting point 260°-262° C.

1. temperatureis heated for 15 minutes to 100° C.
2. temperaturethe reaction mixture is heated for 12 hours to 100° C
3. customThe solvent is removed under reduced pressure
4. additionthe residue treated with cold water
5. filtrationThe solid matter is filtered off
6. customrecrystallized from ethyl acetate/methylene chloride