反应详情

A solution of 103.5 mg (0.466 mmol) of 4,4-dimethyl-7-carboxythiochroman and 77.8 mg (0.468 mmol) of ethyl 4-hydroxybenzoate in 10 ml of methylene chloride was treated sequentially with 14.2 mg (0.116 mmol) of 4-dimethylaminopyridine and 96.9 mg (0.47 mmol) of 1,3-dicyclohexylcarbodiimide. The reaction mixture was stirred at room temperature for 120 hours and then filtered and the residue washed with 10 ml of methylene chloride. The filtrate was concentrated in-vacuo and the residue purified by flash chromatography (silica; 5% ethyl acetate in hexanes) to give the title compound as a colorless oil. PMR (CDCl3): 1.38 (6H, s), 1.42 (3H, t, J~7.1 Hz), 2.02 (2H, m), 3.08 (2H, m), 4.41 (2H, q, J~7.1 Hz), 7.29 (2H, d, J~8.7 Hz), 7.51 (1H, d, J~8.3 Hz), 7.81 1H, dd, J~8.3 Hz, 1.9 Hz), 7.95 (1H, d, J~1.9 Hz), 8.14 (2H, d, J~8.7 Hz)

1. filtrationfiltered
2. washthe residue washed with 10 ml of methylene chloride
3. concentrationThe filtrate was concentrated in-vacuo
4. customthe residue purified by flash chromatography (silica; 5% ethyl acetate in hexanes)