反应详情

4-Ethoxycarbonyl-2-(4-nitrophenyl)-3-pyrazolin-5-one (5.66 g, 20.43 mmol) in distilled tetrahydrofuran (250 ml) containing 10% Palladium|charcoal catalyst (1.13 g) was hydrogenated at atmospheric pressure for 11/2 hours at 0° C. followed by 2 hours at room temperature. The catalyst was then removed by filtration through celite and the celite washed with tetrahydrofuran. The filtrate was then evaporated to dryness to yield the title compound (5.0 g) after trituration (Ether; hexane), νmax (Nujol) 1693, 1675, 1630, 1599, 1585, 1290, 835, 775 cm-1 δ(D6 -Acetone) 1.37 (3H, t, J7 Hz, --OCH2CH3), 3.10 (2H, bs, --NH2), 4.36 (2H, q,J7Hz, --OCH2CH3), 6.80 (2H, d, J9Hz, protons o--NH2), 7.53 (2H, d, J9 Hz, protons m--NH2), 8.35 (1H, s, C3 pyrazole proton). Found: M+, 247.0954; C12H13N3O3 requires M, 247.0956.

1. custom2 hours
2. customat 0° C.
3. customThe catalyst was then removed by filtration through celite
4. washthe celite washed with tetrahydrofuran
5. customThe filtrate was then evaporated to dryness