反应详情

1-Chloroethyl chloroformate (4.4 ml, 40.3 mmol) was added to a cooled (5° C.) solution of Example 14 (5.1 g, 10.1 mmol) in DCM (250 ml). After 1 h at 5° C., the reaction mixture was stirred at RT for 20 h. The solution was concentrated to dryness and then refluxed in MeOH (350 ml) for 3 h. After concentration in vacuo, the oily residue was triturated in Et2O to give the hydrochloride of the desired compound (4.9 g). After basification, the product was chromatographed over silica gel (DCM/MeOH 90/10) to yield the above-titled compound (3.35 g) as an amorphous solid. 1H NMR (CDCl3): 7.64 (2H, d, J=8.4 Hz), 7.25-7.32 (3H, m), 6.72 (2H, d, J=2 Hz), 3.6-3.75 (2H, m), 3.35-3.55 (3H, m), 3.20 (3H, s), 2.16 (1H, br s).

1. concentrationThe solution was concentrated to dryness
2. temperaturerefluxed in MeOH (350 ml) for 3 h
3. concentrationAfter concentration in vacuo
4. customthe oily residue was triturated in Et2O