反应详情

2,4-Diamino-5-methyl-6-(2,5-dimethoxybenzyl)-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidine (8 g) was chlorinated by treatment with Vilsmeier reagent prepared by slowly adding thionyl chloride (28.6) in dry chloroform (25 ml) to a solution of dimethylformamide (17.5) in chloroform (100 ml) at 0°-5° C. The cold mixture of the pyridopyrimidine and Vilsmeier reagent was stirred, gradually allowed to reach ambient temperatures and then heated at reflux for 3 hours. It was then treated with ethanolic base (80 ml) maintaining the temperature at 25°-30° C. with cooling. The brown product formed was isolated, treated further with aqueous ammonia and then recrystallized from ethanol to give 2,4-diamino-5-methyl-6-(2,5-dimethoxybenzyl)-7-chloropyrido[2,3-d]pyrimidine, m.p. 193°-196° (dec.).

1. temperatureheated
2. temperatureat reflux for 3 hours
3. temperaturemaintaining the temperature at 25°-30° C.
4. temperaturewith cooling
5. customThe brown product formed
6. customwas isolated
7. customrecrystallized from ethanol