Butyl vinyl ether → Methyl 2-acetyl-4-methoxybenzoate

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl 2-bromo-4-methoxybenzoate (4) (5.9 g, 23.9 mmol), butyl vinyl ether (15.4 mL, 119.4 mmol), Ph3P (939.0 mg, 3.6 mmol), Et3N (4.3 mL, 31.0 mmol), and Pd(OAc)2 (343.0 mg, 1.8 mmol) in MeCN (45 mL) is stirred under argon at 97° C. for 18 h, cooled to room temperature, diluted with H2O (50 mL), and filtered through Celite® (H2O rinse). The filtrate is concentrated to dryness at reduced pressure. The residue plus tetrahydrofuran (140 mL) and 10% HCl (140 mL) were stirred for 2 h. After tetrahydrofuran removal at reduced pressure, the residue is extracted with dichloromethane (3×70 mL). The extract is washed (brine) and dried. After solvent removal at reduced pressure, the residue is purified on silica gel (16.7% to 33.3% ethyl acetate/hexane) to give 4.8 g (96%) of 5 as a yellow solid, mp 48-50° C. IR 2962, 1733, 1688, 1258 cm−1; 1H NMR (CDCl3) δ 2.50 (s, 3H, CH3CO), 3.86 (s, 6H, CH3O, CO2CH3), 6.76 (d, J=2.0 Hz, 1H, 3-PhH), 6.93 (dd, J=7.2, 2.0 Hz, 1H, 5-PhH), 7.90 ppm (d, J=7.2 Hz, 1H, 6-PhH).

Provenance & Evidence