1,3-Dibromo-5,5-dimethylhydantoin → Cholesta-5,7-diene-1,3-diyl diacetate

HRID 2166676Notes

Reaction equation

HRID 2166676 reaction equation
[C:1]([O:4][C@@H:5]1[C@@:29]2([CH3:30])[C:9](=[CH:10][CH2:11][C@@H:12]3[C@@H:28]2[CH2:27][CH2:26][C@@:25]2([CH3:31])[C@H:13]3[CH2:14][CH2:15][C@@H:16]2[C@H:17]([CH3:24])[CH2:18][CH2:19][CH2:20][CH:21]([CH3:23])[CH3:22])[CH2:8][C@@H:7]([O:32][C:33](=[O:35])[CH3:34])[CH2:6]1)(=[O:3])[CH3:2].CCCCCC.BrN1C(C)(C)C(=O)N(Br)C1=O.CC1C=C(C)N=C(C)C=1>C1(C)C(C)=CC=CC=1.C(OCC)(=O)C>[C:1]([O:4][C@@H:5]1[C@@:29]2([CH3:30])[C:9](=[CH:10][CH:11]=[C:12]3[C@@H:28]2[CH2:27][CH2:26][C@@:25]2([CH3:31])[C@H:13]3[CH2:14][CH2:15][C@@H:16]2[C@H:17]([CH3:24])[CH2:18][CH2:19][CH2:20][CH:21]([CH3:22])[CH3:23])[CH2:8][C@@H:7]([O:32][C:33](=[O:35])[CH3:34])[CH2:6]1)(=[O:3])[CH3:2]

Participants

7

Reactant 4

HCID 64791,3-Dibromo-5,5-dimethylhydantoinHCID 79532,4,6-TrimethylpyridineHCID 8058HexaneHCID 53826710Cholest-5-ene-1,3-diyl diacetate

Product 1

HCID 6451738Cholesta-5,7-diene-1,3-diyl diacetateYield 93.8%

Reagents, catalysts & solvents 2

HCID 7237O-XyleneSolvent2×HCID 8857Ethyl AcetateSolvent

Procedure

A soluton of 1α,3β-diacetoxycholest-5-ene (972 mg, 2 m moles), dry hexane (15 ml) and 1,3-dibromo-5,5-dimethyl hydantoin (343 mg, 1.2 m moles) was reacted at the oil bath temperature of 95° C. under the irradiation of infrared rays for 15 minutes. The reaction mixture was cooled, and the resulting 5,5-dimethyl hydantoin and the excessive 1,3-dibromo-5,5-dimethylhydantoin were removed by filtration. The filtrate was concentrated at reduced pressure to afford a residual product. Xylene (6 ml) was added to this substance to form a solution. The resulting solution was added dropwise to a solution held at 170° C. of s-collidine (5 ml) in dry xylene (6 ml), and the reaction was carried out for additional 20 minutes. After the reaction, the hydrobromide of s-collidine was removed by filtration and filtrate was concentrated under reduced pressure to give residual product. The residue was dissolved in ethyl acetate (30 ml). The ethyl acetate solution was washed with 1 N hydrochloric acid (2×10 ml), saturated sodium bicarbonate and water, and dried over anhydrous sodium sulfate. The drying agent was removed by filtration and the filtrate was concentrated under reduced pressure to give 908 mg of residual product.

Workup

  1. temperatureThe reaction mixture was cooled
  2. customthe resulting 5,5-dimethyl hydantoin and the excessive 1,3-dibromo-5,5-dimethylhydantoin were removed by filtration
  3. concentrationThe filtrate was concentrated at reduced pressure
  4. customto afford a residual product
  5. customto form a solution
  6. additionThe resulting solution was added dropwise to a solution
  7. customAfter the reaction
  8. customthe hydrobromide of s-collidine was removed by filtration and filtrate
  9. concentrationwas concentrated under reduced pressure
  10. customto give residual product
  11. washThe ethyl acetate solution was washed with 1 N hydrochloric acid (2×10 ml), saturated sodium bicarbonate and water
  12. dry with materialdried over anhydrous sodium sulfate
  13. customThe drying agent was removed by filtration
  14. concentrationthe filtrate was concentrated under reduced pressure

Sources & evidence

ORD record
ord-70c89391c83c4863b305dd7419e9592c
Source dataset
uspto-grants-1983_06
Patent number
US04388243

Reaction notes

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