反应详情

28 g. (0.141 mole) of 3,4-difluoro-α-methylcinnamic acid, 1 g. of PtO2 in 250 ml. of MeOH is hydrogenated at 45 p.s.i. until the theoretical uptake is completed. The catalyst is filtered off, and the material evaporated to one-third its volume. A 15% potassium hydroxide solution (10 ml.) is added, and the mixture refluxed for 30 minutes when it is poured into water and extracted with ether (2×100 ml.). The aqueous layer is acidified with concentrated HCl and ice. The oil which comes out is extracted into ether, the ether solution dried over MgSO4 and evaporated to leave a Mwear oil which crystallizes. 3,4-difluoro-α-methylhydrocinnamic acid, M.P. 55°-56°, is isolated.

1. filtrationThe catalyst is filtered off
2. customthe material evaporated to one-third its volume
3. additionA 15% potassium hydroxide solution (10 ml.) is added
4. temperaturethe mixture refluxed for 30 minutes when it
5. additionis poured into water
6. extractionextracted with ether (2×100 ml.)
7. extractionThe oil which comes out is extracted into ether
8. dry with materialthe ether solution dried over MgSO4
9. customevaporated
10. customto leave a Mwear oil which
11. customcrystallizes