反应详情

To tert-Butyl 2-(4-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)butanoyl)-hydrazinecarboxylate (245) (200 mg, 0.673 mmol) in 8 ml of DCM was added 2 ml of TFA. The mixture was stirred for 45 min, diluted with ethanol/toluene (8 ml, 1:1), evaporated and co-evaporated with ethanol/toluene (3×10 ml), crystallized with ethanol/EtAc/Hexane, filtered, and dried under vacuum to afford 188 mg (90%) of the title compound. 1H NMR (CD3OD) 6.72 (s, 2H), 5.39 (s, 0.6H), 3.47 (t, 2H, J=6.6 Hz), 2.20 (m, 2H), 1.85 (m, 2H); 13C NMR 172.72, 135.56, 54.93, 39.20, 37.99, 25.20; MS m/z+197.9 (M+H).

1. customevaporated
2. customcrystallized with ethanol/EtAc/Hexane
3. filtrationfiltered
4. customdried under vacuum