反应详情

A solution of 3β-Acetoxy-17-(1H-benzimidazol-1-yl)-16-formylandrosta-5,16-diene (3, 2.04 g, 4.45 mmol) in dry benzonitrile (10 mL) was refluxed in the presence of 10% palladium on activated charcoal (1.02 g, i.e., 50% weight of 3) for 5 h. After cooling to room temperature, the catalyst was removed by filtration through a Celite pad. The filtrate was evaporated, and the residue was purified by FCC [petroleum ether/EtOAc/Et3N (7.5:3:0.5)] gave 1.41 g (73.8%) of pure compound 4: mp 159-160° C.; IR(CHCl3) 3687, 2947, 2854, 2358, 2340, 1725, 1633, 1609, 1557, 1489, 1454, 1373, 1291, 1253, 1195, 1136, 1031, 985, 910, 839, 735, 665, 590, 544, 533, 513, 502, 488 cm−1; 1H NMR (300 MHz, CDCl3) δ 1.02 (s, 3H, 18-CH3), 1.07 (s, 3H, 19-CH3), 2.04 (s, 3H, 3β-OCH3), 4.62 (m, 1H, 3α-H), 5.43 (br s, 1H, 6-H), 5.98 (s, 1H, 16-H), 7.30 (m, 2H, aromatic-Hs), 7.49 (s, 1H, aromatic-H), 7.81 (s, 1H, aromatic-H), and 7.95 (s, 1H, 21-H). HRMS calcd 453.2512 (C28H34O2N2.Na+). found 453.2511.

1. customthe catalyst was removed by filtration through a Celite pad
2. customThe filtrate was evaporated
3. customthe residue was purified by FCC [petroleum ether/EtOAc/Et3N (7.5:3:0.5)]