反应详情

A mixture of 10.0 g. of 6,7-dimethoxy-2-chloro-4-hydrazinoquinazoline, 1.0 g. of p-toluenesulfonic acid and 150 ml. of trimethoxy methane is refluxed with stirring for 19 hours and then stirred for 24 hours at room temperature. The resulting mixture is evaporated in vacuo to dryness and the residue dissolved in 1500 ml. of methylene chloride. This solution is extracted twice with sodium carbonate solution, washed neutral with water, dried and evaporated in vacuo to dryness. The residue is twice crystallized from methylene chloride/ diethyl ether and then from ethanol to obtain 5-chloro-8,9-dimethoxy-1,2,4-triazolo[4,3-c]quinazoline, m.p. 269°-271° C.

1. additionA mixture of 10.0 g
2. stirringstirred for 24 hours at room temperature
3. customThe resulting mixture is evaporated in vacuo to dryness
4. dissolutionthe residue dissolved in 1500 ml
5. extractionThis solution is extracted twice with sodium carbonate solution
6. washwashed neutral with water
7. customdried
8. customevaporated in vacuo to dryness
9. customThe residue is twice crystallized from methylene chloride/ diethyl ether