Acetic Anhydride → Methylprednisolone Impurity 79

HRID 279826Notes

Reaction equation

HRID 279826 reaction equation
[C:1]([O:4][C@:5]1([C@:26]2([CH3:27])[C@H:12]([C@H:13]3[C@H:23]([C@@H:24]([OH:28])[CH2:25]2)[C@:21]2([CH3:22])[C:16](=[CH:17][C:18](=[O:29])[CH:19]=[CH:20]2)[C@@H:15]([CH3:30])[CH2:14]3)[CH2:11][CH2:10]1)[C:6](=[O:9])[CH2:7][OH:8])(=[O:3])[CH3:2].[C:31](OC(=O)C)(=[O:33])[CH3:32]>N1C=CC=CC=1>[C:1]([O:4][C@:5]1([C@:26]2([CH3:27])[C@H:12]([C@H:13]3[C@H:23]([C@@H:24]([OH:28])[CH2:25]2)[C@:21]2([CH3:22])[C:16](=[CH:17][C:18](=[O:29])[CH:19]=[CH:20]2)[C@@H:15]([CH3:30])[CH2:14]3)[CH2:11][CH2:10]1)[C:6](=[O:9])[CH2:7][O:8][C:31](=[O:33])[CH3:32])(=[O:3])[CH3:2]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 1313172717-O-Acetyl-6-methylprednisolone

Product 1

HCID 13131729Methylprednisolone Impurity 79

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

A solution of 1.0 g of 17-acetoxy-11β,21-dihydroxy-6α-methyl-1,4-pregnadiene-3,20-dione in 10 ml of pyridine is stirred with 5 ml of acetic anhydride for one hour at 0° C. Then the mixture is poured on an ice water-sodium chloride solution; the precipitate is filtered off and purified by crystallization from acetone/hexane, thus isolating 810 mg of 17,21-diacetoxy-11β-hydroxy-6α-methyl-1,4-pregnadiene-3,20-dione, mp 216° C.

Workup

  1. filtrationthe precipitate is filtered off
  2. custompurified by crystallization from acetone/hexane

Sources & evidence

ORD record
ord-62c2bd3ff849432298bc6d09f56b6696
Source dataset
uspto-grants-1986_05
Patent number
US04587236

Reaction notes

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