Bromine → HCID 86754250, compound

HRID 1856640Notes

Reaction equation

HRID 1856640 reaction equation
[C:1]([C@@:3]1([OH:25])[CH2:22][CH2:21][C@@:20]2([CH3:23])[C@H:5]([CH2:6][CH2:7][C@@H:8]3[C@@H:19]2[CH2:18][CH2:17][C@@:16]2([CH3:24])[C@H:9]3[CH2:10][CH2:11][C@@H:12]2[C:13](=[O:15])[CH3:14])[CH2:4]1)#[CH:2].[Br:26]Br>CO.Br.C(Cl)Cl>[Br:26][CH2:14][C:13](=[O:15])[C@@H:12]1[C@:16]2([CH3:24])[C@H:9]([C@H:8]3[C@H:19]([CH2:18][CH2:17]2)[C@:20]2([CH3:23])[C@@H:5]([CH2:4][C@:3]([C:1]#[CH:2])([OH:25])[CH2:22][CH2:21]2)[CH2:6][CH2:7]3)[CH2:10][CH2:11]1

Participants

6

Reactant 2

HCID 24408BromineHCID 9906066HCID 9906066, compound

Product 1

HCID 86754250HCID 86754250, compoundYield 86.6%

Reagents, catalysts & solvents 3

HCID 260Hydrogen BromideCatalystHCID 887MethanolSolventHCID 6344DichloromethaneSolvent

Procedure

A solution of 3β-ethynyl-3α-hydroxy-5β-pregnan-20-one (3 g, 8.77 mmol) in MeOH (110 mL) was treated with two drops of HBr (48%), followed by bromine (0.5 mL, 10.8 mmol). The mixture was stirred at room temperature for 1 hr and was poured into ice-water. The separated solid was collected by filtration, washed with water, and dried (3.2 g). This semi-dried solid was then dissolved in EtOAc and dried over anhyd. MgSO4. Filtration and removal of the solvent gave the crude bromo derivative. This crude product was then dissolved in a small amount of CH2Cl2 and poured on a column of silica gel. Elution with hexane:EtOAc mixture (4:1) gave 21-bromo-3β-ethynyl-3α-hydroxy-5β-pregnan-20-one (3.2 g).

Workup

  1. filtrationThe separated solid was collected by filtration
  2. washwashed with water
  3. customdried (3.2 g)
  4. dissolutionThis semi-dried solid was then dissolved in EtOAc
  5. customdried over anhyd
  6. filtrationFiltration and removal of the solvent
  7. customgave the crude bromo derivative
  8. additionpoured on a column of silica gel
  9. washElution with hexane

Sources & evidence

ORD record
ord-3db6fde4f6294b21a64e850b59c8cb76
Source dataset
uspto-grants-2000_11
Patent number
US06143736

Reaction notes

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