反应详情

To a solution of 20.8 g. of 2,4-dichloro-6,7-dimethoxyquinazoline in 400 ml. of methylene chloride is added dropwise 20 g. of hydrazine while maintaining the temperature below 30° C. with cooling. The resulting mixture was stirred for 45 minutes and then allowed to stand overnight at a temperature of 0° C. The mixture is then filtered and the solids washed first with water and then with methanol. The resulting solid material is then taken up in ice-water and stirred for 20 minutes. The mixture is then filtered and the resulting solid is recrystallized from methanol/methylene chloride to obtain 6,7-dimethoxy-2-chloro-4-hydrazino-quinazoline, m.p. 312°-315° C. (decomp.).

1. temperaturewith cooling
2. waitto stand overnight at a temperature of 0° C
3. filtrationThe mixture is then filtered
4. washthe solids washed first with water
5. stirringstirred for 20 minutes
6. filtrationThe mixture is then filtered
7. customthe resulting solid is recrystallized from methanol/methylene chloride