反应详情

温度

40 °C

Potassium hydroxide (0.527 Kg, 9.4 mol) was added to a stirred suspension of methyl 2,4-bis-benzyloxy-5-isopropenyl-benzoate (3.1 Kg, 8 mol, step 4) in methanol (18.6 L) and water (12.4 L) and the mixture was stirred and held at reflux for 3 hours. The methanol was removed under partial vacuum from the vessel, and to the remaining solution was added toluene (62 L). The solution was heated to 40° C. and to the mixture was added conc HCl (1.36 L). The biphasic mixture is heated to 50° C. and the phases separated. The organic phase was washed with water (31 L) at 50° C. and the organic phase was evaporated under reduced pressure to give 2,4-bis-benzyloxy-5-isopropenyl-benzoic acid 2.851 Kg (95% yield) as a colourless solid.

1. temperatureat reflux for 3 hours
2. customThe methanol was removed under partial vacuum from the vessel
3. additionto the remaining solution was added toluene (62 L)
4. additionwas added conc HCl (1.36 L)
5. temperatureThe biphasic mixture is heated to 50° C.
6. customthe phases separated
7. washThe organic phase was washed with water (31 L) at 50° C.
8. customthe organic phase was evaporated under reduced pressure