反应详情

3-[(Dipropylamino)carbonyl]benzoic acid, (1.24 g, 5 mmol) is combined with EDC (0.95 g, 5 mmol) and HOBT (0.69, 5.1 mmol) in 10 mL of DMF and stirred under nitrogen for 1 h. This solution is then added to a solution of L-leucine methyl ester hydrochloride (0.9 g, 5 mmol) and 0.55 mL (5 mmol) of 4-methylmorpholine in 5 mL of DMF. The reaction is continued for 3 days at ambient temperature. It is then quenched with 1 N KH2PO4 and diluted with ethyl acetate. The organic phase is washed with water, 1 N NaHCO3, and brine, and dried over Na2SO4. Concentration and chromatography over silica gel, eluting with 50% ethyl acetate in heptane, affords 1.65 g (4.4 mmol, 88%) of the title compound as a colorless oil which crystallizes on standing. 1H NMR (CDCl3) δ 7.82 (m, 1H), 7.77 (s, 1H), 7.51-7.44 (m, 2H), 6.65 (d, J=8 Hz, 1H), 4.84 (m, 1H), 3.77 (s, 3H), 3.46 (br t, 2H), 3.14 (br t, 2H), 1.78-1.65 (m, 5H), 1.53 (m, 2H), 0.99 (m, 9H), 0.75 (br t, 3H).

1. waitThe reaction is continued for 3 days at ambient temperature
2. customIt is then quenched with 1 N KH2PO4
3. additiondiluted with ethyl acetate
4. washThe organic phase is washed with water, 1 N NaHCO3, and brine
5. dry with materialdried over Na2SO4
6. concentrationConcentration and chromatography over silica gel
7. washeluting with 50% ethyl acetate in heptane