反应详情

A solution of benzothiazole-6-carboxylic acid (4.48 g, 25.0 mmol), tert-butyl carbazate (3.63 g, 27.5 mmol), 3-(3-dimethylaminopropyl)-1-ethylcarbodiimide hydrochloride (5.75 g, 30.0 mmol) and 1-hydroxybenzotriazole (4.05 g, 30.0 mmol) in N,N-dimethylformamide (50 mL) was stirred overnight at room temperature. The reaction mixture was diluted with ethyl acetate, washed twice with water and once with saturated brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by basic silica gel column chromatography (ethyl acetate/tetrahydrofuran=2/1), and crystallized from hexane/acetone to give the title compound (5.51 g, yield 75%) as colorless crystals.

1. washwashed twice with water and once with saturated brine
2. dry with materialdried over anhydrous magnesium sulfate
3. concentrationconcentrated under reduced pressure
4. customThe residue was purified by basic silica gel column chromatography (ethyl acetate/tetrahydrofuran=2/1)
5. customcrystallized from hexane/acetone