反应详情

p-Methoxy-α-toluene thiol (15.4 g., 0.1 mol.) is added to a solution of methacrylic acid (8.6 g., 0.1 mol.) in 50 ml. 2 N sodium hydroxide. The mixture is heated on the steam bath for three hours, then refluxed for two hours and cooled. The mixture is extracted with ether, then the aqueous layer is acidified with concentrated HCl and extracted with dichloromethane. The acidic extracts are washed with brine, dried (MgSO4) and evaporated in vacuo. The resulting semi-solid is taken up in 50 ml. of dichloromethane, diluted with 50 ml. hexane, and chilled. 3-[(4-methoxyphenyl)methylthio]-2-methylpropanoic acid is collected as a white crystalline solid, m.p. 74°-82° (5.5 g.).

1. temperatureThe mixture is heated on the steam bath for three hours
2. temperaturerefluxed for two hours
3. temperaturecooled
4. extractionThe mixture is extracted with ether
5. extractionextracted with dichloromethane
6. washThe acidic extracts are washed with brine
7. dry with materialdried (MgSO4)
8. customevaporated in vacuo
9. additionof dichloromethane, diluted with 50 ml
10. temperaturehexane, and chilled
11. custom3-[(4-methoxyphenyl)methylthio]-2-methylpropanoic acid is collected as a white crystalline solid, m.p. 74°-82° (5.5 g.)