Benzoyl chloride → (20S)-21-hydroxy-20-methylpregn-4-en-3-one benzoate

HRID 1109010Notes

Reaction equation

HRID 1109010 reaction equation
[OH:1][CH2:2][C@@H:3]([CH3:24])[C@@H:4]1[C@:21]2([CH3:22])[C@H:7]([C@H:8]3[C@H:18]([CH2:19][CH2:20]2)[C@:16]2([CH3:17])[C:11](=[CH:12][C:13](=[O:23])[CH2:14][CH2:15]2)[CH2:10][CH2:9]3)[CH2:6][CH2:5]1.C(N(CC)CC)C.[C:32](Cl)(=[O:39])[C:33]1[CH:38]=[CH:37][CH:36]=[CH:35][CH:34]=1>ClCCl>[C:32]([OH:39])(=[O:1])[C:33]1[CH:38]=[CH:37][CH:36]=[CH:35][CH:34]=1.[OH:1][CH2:2][C@@H:3]([CH3:24])[C@@H:4]1[C@:21]2([CH3:22])[C@H:7]([C@H:8]3[C@H:18]([CH2:19][CH2:20]2)[C@:16]2([CH3:17])[C:11](=[CH:12][C:13](=[O:23])[CH2:14][CH2:15]2)[CH2:10][CH2:9]3)[CH2:6][CH2:5]1

Participants

5

Procedure

A solution of (20S)-21-hydroxy-20-methylpregn-4-en-3-one (8.0 g, 24.2 mmole) in dichloromethane (200 mL) was cooled in an ice-water bath and treated sequentially with triethylamine (3.69 mL, 26.6 mmole) and benzoyl chloride (3.09 mL, 26.6 mmole) and stirred for 16 hours at room temperature. After the reaction mixture was diluted with dichloromethane (200 mL), it was extracted with ether, dried over magnesium sulfate and filtered and the filtrate was concentrated to a solid which was purified by flash chromatography to give (20S)-21-hydroxy-20-methylpregn-4-en-3-one benzoate (9.4 g, 89.5%) melting at 193°-195° C. after recrystallization from acetone. IR 1716, 1676, 1614 (m), 1284 cm-1 ; MS (CI) 435 (100%, M+1), 313 (70%, M+1--PhCOOH); 1H NMR (CDCl3) δ 0.77 (3H, s, C18 --Me), 1.04 (d, C22 --Me), 1.19 (s, C19 --Me), 4.05 (1H, dd, 1/2 C21 --CH2), 4.34 (1H, dd, 1/2 C21 --CH2), 5.72 (1H, s, C4 --H), 7.45 (2H, t), 7.56 (1H, t), 8.04 (2H, dd).

Workup

  1. extractionwas extracted with ether
  2. dry with materialdried over magnesium sulfate
  3. filtrationfiltered
  4. concentrationthe filtrate was concentrated to a solid which
  5. customwas purified by flash chromatography

Sources & evidence

ORD record
ord-24f281f282834b82b37b8887c3fa30d2
Source dataset
uspto-grants-1994_06
Patent number
US05318961

Reaction notes

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