3,4-Dimethoxybenzene-1-thiol → HCID 18782892, compound

HRID 1416191Notes

Reaction equation

HRID 1416191 reaction equation
Br[C:2]1[CH:14]=[CH:13][C:5]2[O:6][C:7]([CH3:12])([CH3:11])[C:8]([CH3:10])=[CH:9][C:4]=2[CH:3]=1.CC(C)([O-])C.[Na+].[CH3:21][O:22][C:23]1[CH:24]=[C:25]([SH:31])[CH:26]=[CH:27][C:28]=1[O:29][CH3:30]>C(O)C.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.[Pd]>[CH3:21][O:22][C:23]1[CH:24]=[C:25]([S:31][C:2]2[CH:14]=[CH:13][C:5]3[O:6][C:7]([CH3:12])([CH3:11])[C:8]([CH3:10])=[CH:9][C:4]=3[CH:3]=2)[CH:26]=[CH:27][C:28]=1[O:29][CH3:30]

Participants

6

Reactant 3

HCID 1365393,4-Dimethoxybenzene-1-thiolHCID 149560896-Bromo-2,2,3-trimethyl-2H-benzo[b]pyranHCID 23676156Sodium t-butoxide

Product 1

HCID 18782892HCID 18782892, compoundYield 73.9%

Reagents, catalysts & solvents 2

HCID 11979704Tetrakis(triphenylphosphine)palladiumCatalyst2×HCID 702EthanolSolvent

Procedure

6-Bromo-2,2,3-trimethyl-2H-benzo[b]pyran (7.4 g) (see Preparation 4) was dissolved in absolute ethanol (150 ml), sodium tert-butoxide (8.5 g), 3,4-dimethoxybenzenethiol (5 g) and tetrakis(triphenylphosphine)palladium(O) (0.5 g) were added and the mixture was heated under reflux under a nitrogen atmosphere for 24 hours. A further portion of tetrakis(triphenylphosphine)palladium(O) (0.5 g) was then added and heating was continued for another 24 hours. The solvent was removed under reduced pressure and the residue was taken up in dichloromethane and washed with water. The organic layer was dried (anhydrous sodium sulphate), the solvent removed under reduced pressure and the crude product chromatographed on silica using 1:4 hexane: dichloromethane as the eluent to yield 6-(3,4-dimethoxyphenyl)thio-2,2,3-trimethyl-2H-benzo[b]pyran (7.4 g) as a yellow oil.

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux under a nitrogen atmosphere for 24 hours
  3. temperatureheating
  4. customThe solvent was removed under reduced pressure
  5. washwashed with water
  6. dry with materialThe organic layer was dried (anhydrous sodium sulphate)
  7. customthe solvent removed under reduced pressure
  8. customthe crude product chromatographed on silica using 1:4 hexane

Sources & evidence

ORD record
ord-2bd1efaed2f841ea80de8fd73d223aa0
Source dataset
uspto-grants-1999_06
Patent number
US05912244

Reaction notes

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