Dimethylformamide → 4-Formyl-2-methylbenzoic acid

Participants

Reaction Conditions

Reaction Steps

To 4-bromo-2-methyl benzoic acid (2.50 g, 11.6 mmol) suspended in anhydrous THF (90 ml) at −78° C. was added n-butyl lithium (9.8 ml, 2.5 M in hexane) and dimethylformamide (2.0 ml). The reaction was stirred at −78° C. for 1 h and then warmed to 25° C. and allowed to react for an additional hour. The reaction was quenched with 1 N aqueous hydrochloric acid and extracted with ethyl acetate. The organic layer was extracted with 1 N aqueous sodium hydroxide and the aqueous layer was separated and the pH adjusted with 1 N aqueous hydrochloric acid. The aqueous phase was extracted with ethyl acetate, then washed with brine, dried over sodium sulfate, filtered and concentrated. The resulting crude 4-formyl-2-methylbenzoic acid (900 mg, 47%) was obtained and was used without further purification. 1H NMR (400 MHz, CD3OD): 10.02-10.00 (s, 1H), 8.04-8.01 (d, 1H), 7.81-7.76 (m, 2H), 2.66-2.63 (s, 3H). MS (EI) for C9H8O3: 163 (M−).

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