反应详情

温度

-78 °C

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−).

1. temperaturewarmed to 25° C.
2. customto react for an additional hour
3. customThe reaction was quenched with 1 N aqueous hydrochloric acid
4. extractionextracted with ethyl acetate
5. extractionThe organic layer was extracted with 1 N aqueous sodium hydroxide
6. customthe aqueous layer was separated
7. extractionThe aqueous phase was extracted with ethyl acetate
8. washwashed with brine
9. dry with materialdried over sodium sulfate
10. filtrationfiltered
11. concentrationconcentrated