反应详情

To a stirred and cooled (ice-bath) solution of 24.8 grams methyl 3,4,5-trimethoxyphenyl-acetate (0.103 mol) in 51.8 grams acetic anhydride (0.508 mol) was slowly added 70% perchloric acid (14 ml, 0.163 mol) over a 20 minute period. The cooling bath was removed, and the mixture was stirred at room temperature for 2 hours. The reaction mixture was cooled again in an ice-bath and 600 ml diethyl ether was added with stirring. The orange crystalline perchlorate salt that precipitated was isolated by filtration, washed with diethyl ether and dried to provide 25.3 grams of Compound 8c (67.2% yield) having a melting point of 160°-162° C. (with decomposition).

1. customover a 20 minute
2. customThe cooling bath was removed
3. stirringthe mixture was stirred at room temperature for 2 hours
4. temperatureThe reaction mixture was cooled again in an ice-bath
5. addition600 ml diethyl ether was added
6. stirringwith stirring
7. customThe orange crystalline perchlorate salt that precipitated
8. customwas isolated by filtration
9. washwashed with diethyl ether
10. customdried