Lithium hydroxide, monohydrate → 4,4,4-Trifluorobutanoic acid

A solution of lithium hydroxide monohydrate (324 g) in water (1.8 l) was added to a stirred solution of ethyl 4,4,4-trifluorobutyrate (436 g) in methanol (2.0 l) and dry tetrahydrofuran (2.0 l) and the suspension was stirred overnight. After the suspension was partially evaporated, the residue was diluted with water and washed with diethyl ether. The aqueous layer was acidified with 6M hydrochloric acid and extracted with diethyl ether. The combined extracts were washed (brine), dried (MgSO4), and filtered. The filtrate was evaporated and the residue distilled (b.p. 165°-168° C.) to give 4,4,4-trifluorobutyric acid (347 g, 95%); m.p. 27°-30° C.; partial NMR; (300 MHz, CDCl3): 2.33-2.57 (m, 2H, CF3CH2), 2.66 (t, CH2CO2H).