Isobutyric Acid → 2,2-Dimethyl-3-phenylpropanoic acid

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of diisopropylamine (12.6 g, 125 mmol) in tetrahydrofuran (100 ml) under anhydrous conditions at 0° C. was aged n-butyllithium (80.6 ml, 1.55 M in hexane, 125 mmol). The reaction mixture was stirred for 30 minutes at 5° C. and then isobutyric acid (4.4 q, 50 mmol) was added. The reaction mixture was stirred at 0° C. for 30 minutes and then benzyl bromide (17.1 g, 100 mmol) was added dropwise. The reaction mixture was stirred for 2 hours at ambient temperature, quenched with saturated aqueous ammonium chloride (60 ml) and then acidified with 6N hydrochloric acid with cooling. The aqueous phase was saturated with sodium chloride and extracted with diethyl ether (2×100 ml). The combined organic phase was washed with saturated aqueous sodium chloride (2×25 ml) and then dried over magnesium sulfate and concentrated in vacuo to give a viscous oil. The oil was distilled at 0.2 mmHg and the product was collected at 160°-170° C. The product was purified by chromatography on a 5×15 cm column of silica gel eluted with 10 percent diethyl ether/hexane (1 L) and 50 percent diethyl ether/hexane (1 L) to afford the desired product as a colorless solid. m.p. 58°-9° C.

Provenance & Evidence