反应详情

According to J. Org. Chem. 33:494 (1968), a mixture of 4-methoxy-2-methylbenzoic acid (20 g, 120 mmol) and MeOH (97 mL) containing sulfuric acid (conc., 0.6 mL) was heated under reflux 48 h. After cooling the mixture was evaporated and the residue diluted with diethyl ether and washed with a saturated sodium hydrogen carbonate solution and brine. The organic phase was then separated and dried over sodium sulphate. After evaporation the residue was distilled through a 8 cm Vigreux column to afford the title compound (21.2 g, 98%) as a colourless liquid. Bp 60° C./1 mbar. MS: m/e=180.3 (M+).

1. temperaturewas heated
2. temperatureunder reflux 48 h
3. temperatureAfter cooling the mixture
4. customwas evaporated
5. additionthe residue diluted with diethyl ether
6. washwashed with a saturated sodium hydrogen carbonate solution and brine
7. customThe organic phase was then separated
8. dry with materialdried over sodium sulphate
9. customAfter evaporation the residue
10. distillationwas distilled through a 8 cm Vigreux column