反应详情

To a solution of Fmoc-Lys(Boc)-OH (500 mg, 1.07 mmol) in solution of 5% DMF in THF (21 mL) were added EDC (245 mg, 1.28 mmol), HOBt (173 mg, 1.28 mmol) and tert-butyl-4-amino benzoate (247 mg, 1.28 mmol) at room temperature. The mixture thus obtained was stirred for 10 minutes and then copper chloride (172 mg, 1.28 mmol) was added to the mixture. The mixture was stirred overnight. The mixture was concentrated to dryness and then the residue was purified by flash chromatography on silica and eluted with 5% methanol in dichloromethane to give compound 1 as a colorless oil (286 mg, 42%). 1H NMR (CD3OD) δ 1.38 (s, 9H), 1.45-1.54 (m, 4H), 1.58 (s, 9H), 1.80 (m, 2H), 3.05 (t, 2H), 4.22 (m, 2H), 4.38 (d, 2H), 7.30 (m, 2H), 7.38 (m, 2H), 7.68 (m , 4H), 7.78 (d, 2H), 7.90 (d, 2H); LC-MS (ES+), 544 (M+H-Boc)+, 667 (M+Na)+.

1. customThe mixture thus obtained
2. stirringThe mixture was stirred overnight
3. concentrationThe mixture was concentrated to dryness
4. customthe residue was purified by flash chromatography on silica
5. washeluted with 5% methanol in dichloromethane