反应详情

To a solution of proline-tert-butyl ester (47) (2.00 g, 12 mmol, in CH2Cl2 (15 ml) was added N-carbobenzyloxy-2-methylalanine (3.05 g, 13 mmol), HOBT (2.36 g, 17 mmol) and EDC: (3.43 g, 18 mmol) and the solution was stirred at room temperature under N2 for 48 hours. The solvent was evaporated, the crude material dissolved in EtOAc and washed with 0.5N NaHSO4 (2×), saturated NaHCO3 (2×) and brine and was dried over anhydrous Na2SO4, filtered and evaporated to give a white solid (4.68 g, 100%). 1H-NMR (500 MHz, CDCl3) δ 1.20-2.15 (m, 4H), 1.43 (s, 9H), 1.59 (d, 6H), 3.21-3.79 (m, 2H), 4.35 (br s, 1H), 4.82-5.19 (m, 3H), 5.74 (br s, 1H), 7.17-7.49 (m, 5H). Analytical HPLC (C18 column) 10.66 min. LC-MS (ES+) m/e=391.3 (M+H).

1. customThe solvent was evaporated
2. dissolutionthe crude material dissolved in EtOAc
3. washwashed with 0.5N NaHSO4 (2×), saturated NaHCO3 (2×) and brine
4. dry with materialwas dried over anhydrous Na2SO4
5. filtrationfiltered
6. customevaporated