Imidazole → 3alpha-(t-Butyldimethylsilyloxy)-7alpha,12alpha-dihydroxy-5beta-cholan-24-oic acid

HRID 465138Notes

Reaction equation

HRID 465138 reaction equation
[CH3:1][C@@H:2]([C@@H:8]1[C@@:12]2([CH3:29])[C@@H:13]([OH:28])[CH2:14][C@@H:15]3[C@@:20]4([CH3:26])[CH2:21][CH2:22][C@@H:23]([OH:25])[CH2:24][C@H:19]4[CH2:18][C@@H:17]([OH:27])[C@H:16]3[C@@H:11]2[CH2:10][CH2:9]1)[CH2:3][CH2:4][C:5]([OH:7])=[O:6].N1C=CN=C1.[Si:35](Cl)([C:38]([CH3:41])([CH3:40])[CH3:39])([CH3:37])[CH3:36].O>CN(C)C=O>[Si:35]([O:25][C@@H:23]1[CH2:22][CH2:21][C@@:20]2([CH3:26])[C@H:19]([CH2:18][C@@H:17]([OH:27])[C@@H:16]3[C@@H:15]2[CH2:14][C@H:13]([OH:28])[C@@:12]2([CH3:29])[C@H:11]3[CH2:10][CH2:9][C@@H:8]2[C@H:2]([CH3:1])[CH2:3][CH2:4][C:5]([OH:7])=[O:6])[CH2:24]1)([C:38]([CH3:41])([CH3:40])[CH3:39])([CH3:37])[CH3:36]

Participants

6

Reactant 4

HCID 795ImidazoleHCID 962WaterHCID 28928tert-Butyldimethylsilyl chlorideHCID 221493Cholic Acid

Product 1

HCID 704792183alpha-(t-Butyldimethylsilyloxy)-7alpha,12alpha-dihydroxy-5beta-cholan-24-oic acid

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

Cholic acid, 4.08 g, is dissolved in 10 ml of dry dimethylformamide and 3.40 g of imidazole is added, followed by 3.60 g of t-butyldimethylsilyl chloride. The reaction mixture is allowed to stand overnight at room temperature. The reaction mixture is poured into water, filtered and the precipitate is washed with water. This precipitate is dissolved in 30 ml of tetrahydrofuran and 3 ml of water and 2 ml of acetic acid is added. After 6.5 hours, the solvent is evaporated and the residue chromatographed on 200 g of silica gel with 5% methanol in methylene chloride as eluent, to provide 3α-(t-butyldimethylsilyloxy)-7α,12α-dihydroxy-5β-cholan-24-oic acid, mp 145.5°-148, having the following structural formula: ##STR15##

Workup

  1. filtrationfiltered
  2. washthe precipitate is washed with water
  3. dissolutionThis precipitate is dissolved in 30 ml of tetrahydrofuran
  4. addition3 ml of water and 2 ml of acetic acid is added
  5. waitAfter 6.5 hours
  6. customthe solvent is evaporated
  7. customthe residue chromatographed on 200 g of silica gel with 5% methanol in methylene chloride as eluent

Sources & evidence

ORD record
ord-f6006852e2ce436f95dca7212a259a8a
Source dataset
uspto-grants-1985_10
Patent number
US04550163

Reaction notes

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