反应详情

A solution of acid 147 (32.0 g, 180 mmol) in dry EtOH (250 mL) and CH2SO4 (2.0 mL) was stirred at reflux temperature under N2 for 16 h. The solvent was evaporated, the residue partitioned between ice/water (200 mL) and DCM (50 mL) and the aqueous layer extracted with DCM (2×40 mL). The combined organic layer was washed with saturated aqueous NaHCO3 solution and water, dried and the solvent evaporated to yield ester 148 (33.3 g, 90%) (lit. Tanaka, et. al., J. Med. Chem. 1994, 37, 2071-2078) as a brown oil: 1H NMR δ 7.10-7.21 (m, 4H, H-4, H-5, H-6, H-7), 4.15 (q, J=7.1 Hz, 2H, CH2), 3.10-3.45 (m, 2H, H-1, H-3), 2.82-2.94 (m, 1H, H-2), 2.62-2.68 (m, 2H, H-1, H-3), 4.48 (d, J=7.4 Hz, 2H, CH2CO2), 1.27 (t, J=7.1 Hz, 2H, CH3).

1. temperatureat reflux temperature under N2 for 16 h
2. customThe solvent was evaporated
3. customthe residue partitioned between ice/water (200 mL) and DCM (50 mL)
4. extractionthe aqueous layer extracted with DCM (2×40 mL)
5. washThe combined organic layer was washed with saturated aqueous NaHCO3 solution and water
6. customdried
7. customthe solvent evaporated