Lithium hydroxide, monohydrate → HCID 21950315, compound

Participants

Reaction Steps

The 4-tert-butoxycarbonylamino-2-(4-chlorophenyl)-butyric acid ethyl ester (5.61 g, 16.4 mmol) was dissolved in 40 mL of THF and 10 mL of water, then cooled to 0° C. The mixture was treated with lithium hydroxide mono-hydrate (1.38 g, 32.8 mmol) to afford a yellow solution. The ice-bath was removed, and the mixture was allowed to stir overnight to room temperature. The reaction mixture was concentrated to approximately 15 mL and diluted with water. The aqueous was washed with ethyl acetate (discarded) then treated with 3M HCl solution until acidic (pH=2-3). The resulting white precipitate was extracted with ethyl acetate, and the organics were combined. The organic was washed with brine, separated, dried over MgSO4, filtered, and concentrated in vacuo to afford the 4-tert-butoxycarbonylamino-2-(4-chlorophenyl)-butyric acid as a colorless oil. The material was re-dissolved in a minimal amount of warm (60° C.) hexanes and re-concentrated to afford the pure desired product as a white foam. 1H NMR (CDCl3, 400 MHz) δ 12.05-9.51 (brs, 1H), 7.31-7.25 (m, 4H), 4.59 (brs, 1H), 3.61 (d, J=7.6 Hz, 1H), 3.14 (brs, 2H), 2.28 (m, 1H), 1.92 (m, 1H), 1.43 (s, 9H).

Provenance & Evidence