Hydrazine → Cholestanol benzoate

HRID 2293936Notes

Reaction equation

[C:1]([O:9][C@H:10]1[CH2:34][CH2:33][C@@:32]2([CH3:35])[C@@H:12]([CH2:13][C:14](=O)[C:15]3[C@@H:31]2[CH2:30][CH2:29][C@@:28]2([CH3:36])[C:16]=3[C:17](=O)[CH2:18][C@@H:19]2[C@H:20]([CH3:27])[CH2:21][CH2:22][CH2:23][CH:24]([CH3:26])[CH3:25])[CH2:11]1)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.NN>C(O)C>[C:1]([O:9][C@H:10]1[CH2:34][CH2:33][C@@:32]2([CH3:35])[C@@H:12]([CH2:13][CH2:14][C@@H:15]3[C@@H:31]2[CH2:30][CH2:29][C@@:28]2([CH3:36])[C@H:16]3[CH2:17][CH2:18][C@@H:19]2[C@H:20]([CH3:27])[CH2:21][CH2:22][CH2:23][CH:24]([CH3:26])[CH3:25])[CH2:11]1)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

Conditions

Temperature: 90 °C

Procedure

To 3β-benzoyloxy-5α-cholest-8(14)-ene-7,15-dione 10 (180 mg, 0.35 mmol) dissolved in ethanol (14 mL) was added anhydrous hydrazine (12 μl, 0.38 mmol) and the mixture was heated to 90° C. for 0.75 h. The solvent was evaporated under reduced pressure and the residue was purified by flash column chromatography on 4 g of silica gel 60 using EtOAc/CHCl3 (4:6) yielding 127 mg (71%) of pyridazine 12, which crystallized from CH2Cl2 /EtOAc, mp 215°-216° C. 1H NMR: δ8.06 (d, 2H, J=8.2 Hz), 7.57 (dd, 1H, J=7.4, 7.4 Hz), 7.45 (dd, 2H, J=7.5, 7.8 Hz), 5.09 (m, 1H), 3.18 (dd, 1H, J=5.5, 17.9 Hz), 3.11 (dd, 1H, J=6.9, 16.3 Hz), 2.96 (dd, 1H, J=10.8, 16.3 Hz), 2.64 (dd, 1H, J=12.6, 17.9 Hz), 2.34 (dd, 1H, J=5.7, 10.9 Hz), 2.25 (ddd, 1H, J=2.9, 3.5, 13.1 Hz), 2.05-2.14 (m, 2H), 1.07 (s, 3H), 1.00 (d, 3H, J=6.3 Hz), 0.89 (d, 6H, J=6.6 Hz), 0.87 (s, 3H). IR (Nujol): 1715, 1602, 1318, 1276, 1116 cm-1. Anal. (C34H46N2O2): C, H.

Workup

customThe solvent was evaporated under reduced pressure
customthe residue was purified by flash column chromatography on 4 g of silica gel 60 using EtOAc/CHCl3 (4:6)

Sources & evidence

ORD record: ord-bd647f5df8124f1c8fe1c4a24f85a1c7
Source dataset: uspto-grants-1997_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05688780

Reaction notes

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