3-(3,4-Difluorophenyl)-2-methylprop-2-enoic acid → 3-(3,4-Difluorophenyl)-2-methylpropanoic acid

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Reaction Steps

A mixture of 28 g (0.141 mol) of 3,4-difluoro-α-methylcinnamic acid, 1 g of PtO2, and 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, is poured into water, and is extracted with ether (2×100 ml). The aqueous layer is acidified with concentrated HCI and ice. The oil which separates is extracted into ether, the ether solution dried over MgSO4 and evaporated to leave a clear oil which crystallizes. 3,4-difluoro-α-methylhydrocinnamic acid, M.P. 55-56° C., is isolated.

Provenance & Evidence