4-Methoxybenzenethiol → 6-(4-methoxyphenyl)thio-2,2,3-trimethyl-2H-benzo[b]pyran

HRID 1416177Notes

Reaction equation

HRID 1416177 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:28]=[CH:27][C:26]([SH:29])=[CH:25][CH:24]=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:28]=[CH:27][C:26]([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:25][CH:24]=1

Participants

6

Reactant 3

HCID 127654-MethoxybenzenethiolHCID 149560896-Bromo-2,2,3-trimethyl-2H-benzo[b]pyranHCID 23676156Sodium t-butoxide

Product 1

HCID 187828716-(4-methoxyphenyl)thio-2,2,3-trimethyl-2H-benzo[b]pyran

Reagents, catalysts & solvents 2

HCID 11979704Tetrakis(triphenylphosphine)palladiumCatalystHCID 702EthanolSolvent

Procedure

6-Bromo-2,2,3-trimethyl-2H-benzo[b]pyran (9.637 g) (see Preparation 4) was dissolved in absolute ethanol (200 ml), then sodium tert-butoxide (11.029 g), 4-methoxybenzenethiol (4.9 ml) and tetrakis(triphenylphosphine)palladium(O) (0.454 g) were added and the mixture was heated under reflux under a nitrogen atmosphere for 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 was removed under reduced pressure and the crude product was chromatographed on silica using 1:1, hexane: dichloromethane as the eluent to yield 6-(4-methoxyphenyl)thio-2,2,3-trimethyl-2H-benzo[b]pyran (7.823 g) as a yellow oil.

Workup

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

Sources & evidence

ORD record
ord-27064be600dc4420b1b3b37a8c74f3e6
Source dataset
uspto-grants-1999_06
Patent number
US05912244

Reaction notes

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