反应详情

A solution of 2-{[(9H-fluoren-9-ylmethoxy)carbonyl]amino}ethyl 4-nitrobenzoate (7.47 g, 17 mmoles) in 1 liter of ethyl acetate, containing 1.5 g of 10% Pd on carbon (wet) is evacuated and filled with H2 twice. The mixture is subjected to hydrogen at 1 atmosphere of pressure for two hours. The catalyst is filtered off on a Celite pad and the solution is concentrated in vacuo, yielding a yellow oil. Purification on silica gel using a gradient of 30-45% ethyl acetate in hexanes provided 5.436 g (80%) of the title compound as a white solid. 400 MHz 1H NMR (CDCl3) δ: 7.86 (d, J=8.4 Hz, 2H), 7.75 (d, J=7.3 Hz, 2H), 7.58 (d, J=7.3 Hz, 2H), 7.39 (t, J=7.3 Hz, 2H), 7.30 (t, J=7.5 Hz, 1H), 6.64 (d, J=8.4 Hz, 2H), 5.13 (br. t, 1H), 4.40 (d, J=7.0 Hz, 2H), 4.36 (t, J=5.1 Hz, 2H), 4.22 (t, J=7.0 Hz, 1H), 4.1-4.0 (br. s, 2H), 3.65-3.55 (m, 2H). LCMS: 403 [M+H].

1. customis evacuated
2. additionfilled with H2 twice
3. filtrationThe catalyst is filtered off on a Celite pad
4. concentrationthe solution is concentrated in vacuo
5. customyielding a yellow oil
6. customPurification on silica gel using a gradient of 30-45% ethyl acetate in hexanes