反应详情

A mixture of 2-(4-nitro-1,3-dioxoisoindolin-2-yl)-4-carbamoylbutanoic acid (1.75 g, 5.45 mmol) and 10% Pd/C (0.2 g) in methanol (52 mL) is hydrogenated at 50 psi of hydrogen for 2 hours. The mixture is filtered through celite and the celite pad is washed with methanol (30 mL). The filtrate is concentrated in vacuo and the residue is slurried with ethyl acetate (20 mL) for 30 min. The resulting slurry is filtered and the solid is washed with ethyl acetate (10 mL) and dried (60° C., <1 mmHg) to give 2-(4-amino-1,3-dioxoisoindolin-2-yl)-4-carbamoylbutanoic acid (1.39 g, 88%) as a yellow solid; mp 165-167° C.; 1H NMR (DMSO-d6) δ13.08 (b, 1H), 7.46 (t, J=7.8 Hz, 1H), 7.22 (s, 1H), 7.02-6.97 (dd, J=4.1 and 5.5 Hz, 1H), 6.73 (s, 1H), 6.51 (s, 2H), 4.68-4.62 (dd, J=4.5 and 10.5 Hz, 1H), 2.50-1.99 (m, 4H); 13C NMR (DMSO-d6) δ173.07, 170.75, 168.88, 167.63, 146.66, 135.36, 132.03, 121.58. 110.87, 108.63, 50.74, 31.34, 24.03; Anal. Calcd. For C13H13N3O5: C, 53.60; H, 4.50; N, 14.43. Found: C, 53.71; H, 4.40; N, 14.31.

1. filtrationThe mixture is filtered through celite
2. washthe celite pad is washed with methanol (30 mL)
3. concentrationThe filtrate is concentrated in vacuo
4. filtrationThe resulting slurry is filtered
5. washthe solid is washed with ethyl acetate (10 mL)
6. customdried (60° C., <1 mmHg)