反应详情

N,O-dimethyl-hydroxylamine hydrochloride (10 mg, 0.10 mmol, 1.2 equivalent) is added at room temperature to a stirred solution of trans-4-benzyloxycarbonylamino-cyclohexanecarboxylic acid (23 mg, 0.08 mmol, 1.0 eq) in N,N-dimethylformamide (5 mL), followed by O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (63 mg, 0.16 mmol, 2.0 eq) and sodium hydrogen carbonate (15 mg, 0.18 mmol, 2.2 eq). After 12 hours stirring at room temperature, solvent is evaporated and the residue is extracted with ethyl acetate (3×10 mL) and a saturated ammonium chloride aqueous solution (10 mL). The combined organic layers are dried over sodium sulfate, filtered and concentrated to give a residue that is purified by column chromatography (silica gel, eluent: petroleum ether:ethyl acetate, 2:1, v/v) to afford [trans-4-(methoxy-methyl-carbamoyl)-cyclohexyl]-carbamic acid benzyl ester as a colorless solid (8 mg, 30% yield).

1. customsolvent is evaporated
2. extractionthe residue is extracted with ethyl acetate (3×10 mL)
3. dry with materialThe combined organic layers are dried over sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated
6. customto give a residue that
7. customis purified by column chromatography (silica gel, eluent