N-bromobutanimide → 81968-78-7

HRID 329532Notes

Reaction equation

HRID 329532 reaction equation
[CH3:1][C:2]([C@@H:4]1[C@@:8]2([CH3:26])[CH2:9][CH2:10][C@@H:11]3[C@@:16]4([CH3:25])[CH2:17][CH2:18][C@H:19]([O:21]C(C)=O)[CH2:20][C:15]4=[CH:14][CH2:13][C@H:12]3[C@@H:7]2[CH2:6][CH2:5]1)=[O:3].BrN1C(=O)CCC1=O.C(=O)(O)[O-].[Na+]>C(Cl)(Cl)(Cl)Cl>[OH:21][C@H:19]1[CH2:18][CH2:17][C@@:16]2([CH3:25])[C:15](=[CH:14][CH:13]=[C:12]3[C@@H:11]2[CH2:10][CH2:9][C@@:8]2([CH3:26])[C@H:7]3[CH2:6][CH2:5][C@@H:4]2[C:2](=[O:3])[CH3:1])[CH2:20]1

Participants

5

Reactant 3

HCID 67184N-bromobutanimideHCID 516892Sodium BicarbonateHCID 27237223beta-Acetoxy-5-pregnene-20-one

Product 1

HCID 9947581968-78-7

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Procedure

Pregnenolone acetate (15.0 g) was dissolved in 100 ml of carbon tetrachloride, and after addition of 8.95 g of N-bromosuccinimide and 8 g of a finely powdered sodium bicarbonate, the mixture was refluxed for 30 minutes. After cooling, the reaction mixture was washed with water and dried, followed by the distilling off of the solvent under vacuum. The yellow solid residue was dissolved in 100 ml of xylene and after addition of 4.5 ml of collidine, the solution was refluxed on an oil bath for 1 hour. After cooling, ethyl acetate was added to the solution and the mixture was successively washed with water, dilute hydrochloric acid, water and an aqueous solution of sodium bicarbonate. The washed solution was dried and the solvent was distilled off under vacuum. The residue was dissolved in 100 ml of methanol under heating. After cooling, 4 g of potassium hydroxide was added to the solution, which was then stirred for 4 hours at room temperature. The resulting white precipitate was filtered off. After washing with methanol, the filtrate was freed of the solvent by vacuum distillation, whereby 6.46 g of a crude product of the desired 5,7-diene compound was obtained.

Workup

  1. temperaturethe mixture was refluxed for 30 minutes
  2. temperatureAfter cooling
  3. washthe reaction mixture was washed with water
  4. customdried
  5. dissolutionThe yellow solid residue was dissolved in 100 ml of xylene
  6. additionafter addition of 4.5 ml of collidine
  7. temperaturethe solution was refluxed on an oil bath for 1 hour
  8. temperatureAfter cooling
  9. additionethyl acetate was added to the solution
  10. washthe mixture was successively washed with water, dilute hydrochloric acid, water
  11. customThe washed solution was dried
  12. distillationthe solvent was distilled off under vacuum
  13. dissolutionThe residue was dissolved in 100 ml of methanol
  14. temperatureunder heating
  15. temperatureAfter cooling
  16. addition4 g of potassium hydroxide was added to the solution, which
  17. filtrationThe resulting white precipitate was filtered off
  18. washAfter washing with methanol
  19. distillationthe filtrate was freed of the solvent by vacuum distillation, whereby 6.46 g of a crude product of the desired 5,7-diene compound
  20. customwas obtained

Sources & evidence

ORD record
ord-464cb63caefa40cc9305974a12be5bdd
Source dataset
uspto-grants-1990_01
Patent number
US04891364

Reaction notes

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