Bromine → HCID 87844273, compound

HRID 1856641Notes

Reaction equation

HRID 1856641 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 10736101HCID 10736101, compound

Product 1

HCID 87844273HCID 87844273, compoundYield 74.2%

Reagents, catalysts & solvents 3

HCID 260Hydrogen BromideCatalystHCID 887MethanolSolventHCID 6344DichloromethaneSolvent

Procedure

A solution of 3β-ethynyl-3α-hydroxy-5α-pregnan-20-one (2.3 g, 6.72 mmol) in MeOH (80 mL) was treated with two drops of HBr (48%), followed by bromine (0.4 mL, 7.73 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 (2.5 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 (85:15) gave 21-Bromo-3β-ethynyl-3α-hydroxy-5α-pregnan-20-one (2.1 g).

Workup

  1. filtrationThe separated solid was collected by filtration
  2. washwashed with water
  3. customdried (2.5 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-e57b93e907c549b097673ad4bcc25a9a
Source dataset
uspto-grants-2000_11
Patent number
US06143736

Reaction notes

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