反应详情

Acetylchloride (6.7 mL, 91 mmol) was added dropwise to 750 mL dry methanol cooled on an ice-bath under N2 atmosphere. After completion of the addition, the solution was stirred at RT for 30 min. Subsequently, 16.0 g (90 mmol) 3-methyl benzo[b]furan-2-carboxylic acid was added and the solution was refluxed for 17 h under N2 atmosphere. The solution was cooled on an ice-bath to 0° C. and 500 mL ice-cold water was added. The resulting white precipitate was collected by filtration and washed with cold methanol. Yield: 16.1 g (94%) of a white solid. 1H-NMR (200 MHz, CDCl3): δ 7.72 (d, J=8 Hz, 1H), 7.60 (t, J=8 Hz, 1H), 7.53 (t, J=8 Hz, 1H), 7.41 (d, J=8 Hz, 1H), 4.08 (s, 3H), 2.73 (s, 3H) ppm.

1. temperaturecooled on an ice-bath under N2 atmosphere
2. additionAfter completion of the addition
3. temperaturethe solution was refluxed for 17 h under N2 atmosphere
4. temperatureThe solution was cooled on an ice-bath to 0° C.
5. filtrationThe resulting white precipitate was collected by filtration
6. washwashed with cold methanol