Hydrogen Bromide → Methyl 3alpha-acetoxy-6-bromo-7-keto-5beta-cholanoate

HRID 346117Notes

Reaction equation

HRID 346117 reaction equation
[C:1]([O:4][C@@H:5]1[CH2:29][CH2:28][C@@:27]2([CH3:30])[C@H:7]([CH2:8][C:9](=[O:32])[C@@H:10]3[C@@H:26]2[CH2:25][CH2:24][C@@:23]2([CH3:31])[C@H:11]3[CH2:12][CH2:13][C@@H:14]2[C@H:15]([CH3:22])[CH2:16][CH2:17][C:18]([O:20][CH3:21])=[O:19])[CH2:6]1)(=[O:3])[CH3:2].[Br:33]Br.Br.O>C(O)(=O)C>[C:1]([O:4][C@@H:5]1[CH2:29][CH2:28][C@@:27]2([CH3:30])[C@H:7]([CH:8]([Br:33])[C:9](=[O:32])[C@@H:10]3[C@@H:26]2[CH2:25][CH2:24][C@@:23]2([CH3:31])[C@H:11]3[CH2:12][CH2:13][C@@H:14]2[C@H:15]([CH3:22])[CH2:16][CH2:17][C:18]([O:20][CH3:21])=[O:19])[CH2:6]1)(=[O:3])[CH3:2]

Participants

6

Reactant 4

HCID 260Hydrogen BromideHCID 962WaterHCID 24408BromineHCID 18647600Cholan-24-oic acid, 3-(acetyloxy)-7-oxo-, methyl ester, (3alpha,5beta)-

Product 1

HCID 18647599Methyl 3alpha-acetoxy-6-bromo-7-keto-5beta-cholanoateYield 121.9%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent2×

Procedure

A solution of methyl 3α-acetoxy-7-keto-5β-cholanoate (5.6 g, 12.54 mmoles) in acetic acid (100 ml) was added with a bromine solution (2.8 g) in acetic acid (10 ml) and immediately after with 48% hydrobromic acid (0.74 ml). The resulting reaction mixture was left to react overnight under strong magnetic stirring, then it was poured into water (300 ml) and filtered under vacuum to obtain a solid (8,03 g) which was subjected to flash chromatography on silica, eluting with methylene chloride/methanol 99.5:0.5, to yield 6.0 g of a pure product (91%).

Workup

  1. customThe resulting reaction mixture
  2. waitwas left
  3. customto react overnight under strong magnetic stirring
  4. filtrationfiltered under vacuum

Sources & evidence

ORD record
ord-e8eac05165e34a028344bf7578c8875b
Source dataset
uspto-grants-1991_10
Patent number
US05061701

Reaction notes

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