反应详情

3-(tert-butoxycarbonylamino)propanoic acid (4 g, 21.2 mmol, 1.0 equiv) was dissolved in DCM (100 mL). Then methanesulfonamide (1.43 g, 15.1 mmol, 0.7 equiv), EDCI (3.45 g, 18.2 mmol, 0.85 equiv) and DMAP (0.37 g, 3 mmol, 0.15 equiv) were added to the mixture and stirred for 2 h at r.t. The reaction mixture was cooled down to 0° C., ice water (100 mL) was added. The mixture was stirred for 15 min, separated and the water layer was extracted twice with DCM. The combined organic layer was washed by 5% HCl, brine, dried over Na2SO4, concentrated to give tert-butyl 3-(methylsulfonamido)-3-oxopropylcarbamate as a gray oil (3.6 g, 90%). ESI-MS (M+H)+: 267.1. 1H NMR (400 MHz, DMSO-d6) δ: 6.91˜6.83 (brs, 1H), 3.36 (s, 3H), 3.19˜3.12 (m, 2H), 2.41 (t, 2H), 1.37 (s, 9H).

1. temperatureThe reaction mixture was cooled down to 0° C.
2. stirringThe mixture was stirred for 15 min
3. customseparated
4. extractionthe water layer was extracted twice with DCM
5. washThe combined organic layer was washed by 5% HCl, brine
6. dry with materialdried over Na2SO4
7. concentrationconcentrated