Diethyl Ether → 3alpha-Nicotinoyloxy-5alpha-pregnan-20-one

HRID 2253817Notes

Reaction equation

[OH:1][C@@H:2]1[CH2:21][CH2:20][C@@:19]2([CH3:22])[C@@H:4]([CH2:5][CH2:6][C@@H:7]3[C@@H:18]2[CH2:17][CH2:16][C@@:15]2([CH3:23])[C@H:8]3[CH2:9][CH2:10][C@@H:11]2[C:12](=[O:14])[CH3:13])[CH2:3]1.Cl.[C:25](Cl)(=[O:32])[C:26]1[CH:31]=[CH:30][CH:29]=[N:28][CH:27]=1.CCOCC>CN(C)C1C=CN=CC=1.N1C=CC=CC=1>[C:25]([O:1][C@@H:2]1[CH2:21][CH2:20][C@@:19]2([CH3:22])[C@@H:4]([CH2:5][CH2:6][C@@H:7]3[C@@H:18]2[CH2:17][CH2:16][C@@:15]2([CH3:23])[C@H:8]3[CH2:9][CH2:10][C@@H:11]2[C:12](=[O:14])[CH3:13])[CH2:3]1)(=[O:32])[C:26]1[CH:31]=[CH:30][CH:29]=[N:28][CH:27]=1

Participants

Conditions

Temperature: 90 °C

Procedure

To 3α-hydroxy-5α-pregnan-20-one (464 mg, 318.5 g/m, 1.5 mmol) and 4-dimethylaminopyridine (DMAP, 195 mg, 122.17 g/m, 1.6 mmol) dissolved in 10 mL of dry pyridine was added nicotinoyl chloride hydrochloride (285 mg, 178.02 g/m, 1.6 mmol). The reaction mixture was heated at 90° C. for 5 hours and poured into 300 mL of ether. The organic layer was washed twice with saturated sodium bicarbonate, twice with water, dried over magnesium sulfate, and concentrated in vacuo to give the crude product. The crude material was filtered through a bed of silica gel using hexane/ethyl acetate (50:50) elution. The first two fractions gave the titled compound (604 mg, 421 6/m, 1.43 mmol, 96%).

Workup

washThe organic layer was washed twice with saturated sodium bicarbonate, twice with water
dry with materialdried over magnesium sulfate
concentrationconcentrated in vacuo
customto give the crude product
filtrationThe crude material was filtered through a bed of silica gel
washhexane/ethyl acetate (50:50) elution

Sources & evidence

ORD record: ord-c9a77b00c4f84dec96c98f59d5a657bc
Source dataset: uspto-grants-1993_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05232917

Reaction notes

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