反应详情

To a solutuion of 5-chloro-thiophene-2-sulfonic acid tert-butylamide (310 mg, 1.22 mmol) in THF (10 mL) at −78° C. was added n-Buli (1.6 M in hexane, 1.7 mL, 2.7 mmol) dropwise. The resultant solution was warmed up to −30° C. and maintained at −20° C.–−30° C. for 10 min. It was rmixed with a solution of 4-methylbenzenesulfonyl azide (361 mg, 1.83 mmol) in THF (2 mL). The mixture was stirred at ambient temperature for 1 h before diluted with brine solution (30 mL) and washed with toluene (20 mL). The organic phase was separated and mixed with NaBH4 (500 mg, 13.2 mmol) and H2O (5 mL). The mixture was stirred for 2 h. at room temperature, then diluted with brine solution (50 mL) and washed with ethyl acetate (50 mL, 3×). The combined organic phases were dried over MgSO4, filtered, and concentrated. Flash chromatography (hexanes/ethyl acetate, 4:1) then provided 3a (250 mg) as a yellow oil.

1. temperaturemaintained at −20° C.–−30° C. for 10 min
2. washwashed with toluene (20 mL)
3. customThe organic phase was separated
4. stirringThe mixture was stirred for 2 h. at room temperature
5. washwashed with ethyl acetate (50 mL, 3×)
6. dry with materialThe combined organic phases were dried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated