反应详情

K2CO3 (3.0 g, 21 mmol) followed by iodomethane (1.2 mL, 20 mmol) were added to a solution of 4-benzyloxy-3,5-dimethyl-benzoic acid (5.0 g, 20 mmol) in DMF (100 mL) and the mixture was stirred at room temperature for 6 h. The solution was diluted with water and was acidified with 1% aq. HCl. The mixture was extracted with EtOAc (3×200 mL). The combined organics were washed with water (200 mL), dried over sodium sulfate, filtered, and concentrated. The residue was taken up in degassed 2-propanol (100 mL). Pd/C (10%, 500 mg) was added and the mixture was again degassed and was backfilled with Ar. The mixture was introduced to an atmosphere of H2 (balloon) and was stirred overnight. The solids were removed by filtration through Celite and the filtrate was concentrated in vacuo to provide methyl 4-hydroxy-3,5-dimethyl-benzoate (91%) as a white solid. 1H NMR (400 MHz, DMSO) δ 7.56 (s, 2H), 3.76 (s, 3H), 3.38 (s, 9H), 2.19 (s, 6H).

1. extractionThe mixture was extracted with EtOAc (3×200 mL)
2. washThe combined organics were washed with water (200 mL)
3. dry with materialdried over sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated
6. additionPd/C (10%, 500 mg) was added
7. customthe mixture was again degassed
8. additionThe mixture was introduced to an atmosphere of H2 (balloon)
9. stirringwas stirred overnight
10. customThe solids were removed by filtration through Celite
11. concentrationthe filtrate was concentrated in vacuo