反应详情

To the crude 2-acetylamino-4,5-dimethoxy-benzoic acid methyl ester obtained above was added ammonium acetate (7.98 g, 0.104 mol) and acetic acid (10 mL). The mixture was heated at reflux in a pressure tube until the formation of the desired cyclization product, as indicated by LC/MS: m/z 221 (M+H). After cooling to RT, the reaction mixture was diluted with water, and extracted with EtOAc 3 times. The combined organic phase was basified with aq. NaOH solution, and washed 3 times with EtOAc. The aqueous layer was then acidified with aq. HCl and extracted three times with EtOAc. The combined organic extract was dried over Na2SO4 and concentrated in vacuo, affording 6,7-dimethoxy-2-methyl-quinazolin-4-ol (0.15 g), which was used without further purification. LC/MS: m/z 221 (M+H).

1. temperatureThe mixture was heated
2. temperatureat reflux in a pressure tube until the formation of the desired cyclization product
3. extractionextracted with EtOAc 3 times
4. washwashed 3 times with EtOAc
5. extractionextracted three times with EtOAc
6. extractionThe combined organic extract
7. dry with materialwas dried over Na2SO4
8. concentrationconcentrated in vacuo