3-Methoxybenzenethiol → 6-(3-methoxyphenyl)thio-2,2,3-trimethyl-2H-benzo[b]pyran

HRID 1416178

Reaction equation

HRID 1416178 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:29])[CH:26]=[CH:27][CH:28]=1>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:29][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][CH:28]=1

Participants

6

Reactant 3

HCID 849893-MethoxybenzenethiolHCID 149560896-Bromo-2,2,3-trimethyl-2H-benzo[b]pyranHCID 23676156Sodium t-butoxide

Product 1

HCID 187828766-(3-methoxyphenyl)thio-2,2,3-trimethyl-2H-benzo[b]pyranYield 89.8%

Reagents, catalysts & solvents 2

HCID 11979704Tetrakis(triphenylphosphine)palladiumCatalyst2×HCID 702EthanolSolvent

Procedure

6-Bromo-2,2,3-trimethyl-2H-benzo[b]pyran (6.5 g) (see Preparation 4) was dissolved in absolute ethanol (135 ml), then sodium tert-butoxide (7.5 g), 3-methoxybenzenethiol (3.6 g) and tetrakis(triphenylphosphine)palladium(O) (0.35 g) were added and the mixture was heated under reflux under a nitrogen atmosphere for 48 hours. Further tetrakis(triphenylphosphine)palladium(O) (0.3 g) was added and heating was continued for a further 48 hours. The solvent was removed under reduced pressure and the residue was dissolved 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 1:1 hexane: dichloromethane as the eluent to yield 6-(3-methoxyphenyl)thio-2,2,3-trimethyl-2H-benzo[b]pyran (7.2 g) as an oil.

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux under a nitrogen atmosphere for 48 hours
  3. temperatureheating
  4. customThe solvent was removed under reduced pressure
  5. dissolutionthe residue was dissolved in dichloromethane
  6. washwashed with water
  7. dry with materialThe organic layer was dried (anhydrous sodium sulphate)
  8. customthe solvent removed under reduced pressure
  9. customthe crude product chromatographed on silica using 1:1 hexane

Sources & evidence

ORD record
ord-93d3b7e6ae6c47ad8c7c63f53a437795
Source dataset
uspto-grants-1999_06
Patent number
US05912244

Linked notes

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