反应详情

To a mixture of tert-butyl (S)-3-cyclopentyl-1-(methylamino)propan-2-ylcarbamate (900 mg, 3.52 mmol) and Et3N (1.5 mL, 10.6 mmol) in CH2Cl2 (10 mL) was added dropwise a solution of CbzCl (720 mg, 4.22 mmol) in CH2Cl2 (5 mL) at 0° C. After stirring for an additional 2 h, water (30 mL) was added and the mixture was extracted with CH2Cl2 (2×10 mL). The combined organic layers were washed with brine, dried over MgSO4 and concentrated. The residue was purified by silica chromatography to obtain benzyl (S)-2-(t-butoxycarbonylamino)-3-cyclopentylpropylmethylcarbamate (550 mg, 40%) as an oil. 1H NMR (CDCl3, 400 MHz) δ 1.10 (m, 2H), 1.43 (s, 9H), 1.49 (m, 3H), 1.60 (m, 3H), 1.81 (m, 3H), 2.96 (s, 3H), 3.15 (m, 1H), 3.40 (m, 1H), 3.83 (brs, 1H), 4.57 (brs, 1H), 5.16 (s, 2H), 7.33 (m, 5H).

1. extractionthe mixture was extracted with CH2Cl2 (2×10 mL)
2. washThe combined organic layers were washed with brine
3. dry with materialdried over MgSO4
4. concentrationconcentrated
5. customThe residue was purified by silica chromatography