1,2-Dichloroethane → (+/-)-trans-3-bromo-6-cyano-3,4-dihydro-2,2-dimethyl-4-[(S)-(-)-3-acetylthio-2-methylpropionyloxy]-2H-1-benzopyran

HRID 373341Notes

Reaction equation

HRID 373341 reaction equation
[Br:1][C@H:2]1[C@H:7]([OH:8])[C:6]2[CH:9]=[C:10]([C:13]#[N:14])[CH:11]=[CH:12][C:5]=2[O:4][C:3]1([CH3:16])[CH3:15].C(Cl)CCl.[C:21]([S:24][CH2:25][C@H:26]([CH3:30])[C:27](Cl)=[O:28])(=[O:23])[CH3:22]>N1C=CC=CC=1>[Br:1][C@H:2]1[C@H:7]([O:8][C:27](=[O:28])[C@H:26]([CH3:30])[CH2:25][S:24][C:21](=[O:23])[CH3:22])[C:6]2[CH:9]=[C:10]([C:13]#[N:14])[CH:11]=[CH:12][C:5]=2[O:4][C:3]1([CH3:16])[CH3:15]

Participants

5

Reactant 3

HCID 111,2-DichloroethaneHCID 6932483trans-2,2-Dimethyl-3-bromo-6-cyanochroman-4-olHCID 10954137S-(3-Chloro-2-methyl-3-oxopropyl) (S)-ethanethioate

Product 1

HCID 86745230(+/-)-trans-3-bromo-6-cyano-3,4-dihydro-2,2-dimethyl-4-[(S)-(-)-3-acetylthio-2-methylpropionyloxy]-2H-1-benzopyranYield 98.4%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

To a mixture of 94 g of (±)-trans-3-bromo-6-cyano-3,4-dihydro-2,2-dimethyl-4-hydroxy-2H-1-benzopyran, 800 ml of ethylene chloride and 32.4 ml of pyridine was added 66 g of (S)-(-)-3-acetylthio-2-methylpropionyl chloride under ice-cooling over 5 minutes and stirred for 1.5 hours under room temperature. The reaction mixture was washed with diluted hydrochloric acid once and 10% aqueous sodium chloride solution twice. The organic layer was separated, dried over magnesium sulfate and concentrated under reduced pressure to give 139.8 g of (±)-trans-3-bromo-6-cyano-3,4-dihydro-2,2-dimethyl-4-[(S)-(-)-3-acetylthio-2-methylpropionyloxy]-2H-1-benzopyran as a light yellow oily substance.

Workup

  1. temperaturecooling over 5 minutes
  2. washThe reaction mixture was washed with diluted hydrochloric acid once
  3. customThe organic layer was separated
  4. dry with materialdried over magnesium sulfate
  5. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-5ce8f967996c4edc9e5c322a720cee3e
Source dataset
uspto-grants-1992_11
Patent number
US05162553

Reaction notes

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