反应详情

To a stirred suspension of 450 mg (1.69 mmol) (+)-7-[1,4]dioxan-2-yl-4-methoxy-benzothiazol-2-ylamine and 0.41 ml (5.07 mmol) pyridine in 10 ml dichloromethane at 0° C. was added 0.28 ml (2.20 mmol) phenyl chloroformate and stirring continued at room temperature for 16 h. The reaction mixture was then poured into saturated aqueous sodium bicarbonate solution and extracted three times with ethyl acetate. The combined organic phases were dried over sodium sulfate and concentrated in vacuo. Flash chromatography (1/1 acetone/heptane) followed by trituration in ether and hexane afforded 630 mg (96%) (+)-(7-[1,4]dioxan-2-yl-4-methoxy-benzothiazol-2-yl)-carbamic acid phenyl ester as a white solid. [α]D20=+13.6° (c=0.32, CHCl3), ES-MS m/e (%):387 (M+H+, 100).

1. extractionextracted three times with ethyl acetate
2. dry with materialThe combined organic phases were dried over sodium sulfate
3. concentrationconcentrated in vacuo