反应详情

A mixture of 3-(2'-hydroxy-3',4'-dimethoxy-6'-methylbenzoyl)propionic acid (formula II-1 wherein R=H3CO, X=H, Y=OH, n=2 in the free form) (0.536 part), zinc amalgam (1 part), concentrated hydrochloric acid (1 volume part), water (2 volume parts) and toluene (2 volume parts) was refluxed for 5 hours and, after cooling, the reaction mixture was extracted with diethyl ether. The extract was washed with water and dried. The solvents were distilled off under reduced pressure and the residue was recrystallized from diethyl ether-hexane. The procedure provided 4-(2'-hydroxy-3',4'-dimethoxy-6'-methylphenyl)butyric acid (formula II-2 wherein R=H3CO, X=H, Y=OH, n=2, in the free form) (0.34 part) as colorless needles melting at 98°-100° C.

1. temperaturewas refluxed for 5 hours
2. temperatureafter cooling
3. extractionthe reaction mixture was extracted with diethyl ether
4. washThe extract was washed with water
5. customdried
6. distillationThe solvents were distilled off under reduced pressure
7. customthe residue was recrystallized from diethyl ether-hexane