反应详情

Aqueous potassium hydroxide (50% w/v, 0.2 ml) was added to a suspension of methyl 5-isopropyl-2,4-dimethoxybenzoate (330 mg, 1.39 mmol) in methanol (5 ml) and water (2 ml) and the mixture was stirred and held at reflux for 3 hours. Upon cooling to room temperature the organic solvent was removed in vacuo and the residue acidified by the addition of 2M hydrochloric acid (10 ml). The organic material was extracted with ethyl acetate (2×30 ml) and the combined organic extracts were evaporated in vacuo to afford 5-isopropyl-2,4-dimethoxybenzoic acid (305 mg, 98%) as an off-white solid. 1H NMR (DMSO-d6) 12.07 (1H, br s), 7.57 (1H, s), 6.64 (1H, s), 3.90 (3H, s), 3.85 (3H, s), 3.13 (1H, m), 1.14 (6H, d). MS: [M+H]+ 225.

1. temperatureat reflux for 3 hours
2. customwas removed in vacuo
3. additionthe residue acidified by the addition of 2M hydrochloric acid (10 ml)
4. extractionThe organic material was extracted with ethyl acetate (2×30 ml)
5. customthe combined organic extracts were evaporated in vacuo