反应详情

A mixture of 500 mg 5-chloro-8,9-dimethoxy-1,2,4-triazolo[4,3-c]quinazoline and 25 ml triethylamine in 25 ml. methanol is stirred at 40° C. for 24 hrs. The solution is then evaporated in vacuo to dryness, treated with water, and the aqueous layer extracted several times with chloroform. The combined chloroform extracts, after washing with H2O, is dried over sodium sulfate and evaporated in vacuo to dryness. The residue is dissolved in minimum chloroform and chromotrographed on silica gel, elution being carried out with chloroform and then with chloroform containing increasing concentrations of methanol. The desired fractions are collected, evaporated to dryness in vacuo and the residue crystallized from methylene chloride/diethyl ether to obtain 5,8,9-Trimethoxy-1,2,4-triazolo-[4,3-c]quinazoline, m.p. 245°-250° C.

1. customThe solution is then evaporated in vacuo to dryness
2. additiontreated with water
3. extractionthe aqueous layer extracted several times with chloroform
4. washafter washing with H2O
5. dry with materialis dried over sodium sulfate
6. customevaporated in vacuo to dryness
7. dissolutionThe residue is dissolved in minimum chloroform
8. washchromotrographed on silica gel, elution
9. temperaturewith chloroform containing increasing concentrations of methanol
10. customThe desired fractions are collected
11. customevaporated to dryness in vacuo
12. customthe residue crystallized from methylene chloride/diethyl ether