Potassium Hydroxide → Methyl 4-tert-butylphenylisobutyric acid

Participants

Reaction Steps

A solution of methyl 4-tert-butylphenylacetate (30.00 g, 0.145 mol) and iodomethane (45.41 g, 0.320 mol) in 125 mL of dry THF was added to a slurry of NaH (8.72 g, 0.363 mol) in 200 mL of THF dropwise over 30 minutes. After completion of the addition, the reaction mixture was heated at reflux for 1.5 hr. The reaction was allowed to cool to room temperature, filtered through Celite and concentrated. The residue was diluted in ether, washed with H2O, and dried over MgSO4. Evaporation of the solvent afforded the desired product as an oil. A mixture of the crude methyl 4-tert-butylphenylisobutyrate and 4:1 EtOH/H2O containing KOH (10.07 g, 0.179 mol) were heated to reflux for 4 hr. The EtOH was evaporated in vacuo, the residual solution was acidified to pH 2 with 2N HCl, and the precipitated solid filtered. The white solid was the dried (60° C., 1 mm Hg, 24 hr) to give the desired product (23.45 g, 73.2% from methyl 4-tert-butylphenylacetate). 1H NMR (CDCl3) 1.34 (s, 9H), 1.62 (s, 6H), 7.37 (s, 4H), 11.4-12.4 (brs, 1H). 13C NMR (CDCl3) 26.16, 31.30, 34.35, 45.81, 125.31, 125.48, 140.64, 149.66, 183.57.

Provenance & Evidence