Potassium Iodide → 6-(4-Methoxybenzylthio)-2,2-dimethyl-2H-1-benzopyran

HRID 1656464Notes

Reaction equation

HRID 1656464 reaction equation
Cl[C:2]([CH3:6])([CH3:5])[C:3]#[CH:4].[I-].[K+].C(=O)([O-])[O-].[K+].[K+].[CH3:15][O:16][C:17]1[CH:31]=[CH:30][C:20]([CH2:21][S:22][C:23]2[CH:28]=[CH:27][C:26]([OH:29])=[CH:25][CH:24]=2)=[CH:19][CH:18]=1>CO.C(C(C)=O)C.ClC1C=CC=CC=1Cl.CCOCC>[CH3:15][O:16][C:17]1[CH:18]=[CH:19][C:20]([CH2:21][S:22][C:23]2[CH:28]=[CH:27][C:26]3[O:29][C:2]([CH3:6])([CH3:5])[CH:3]=[CH:4][C:25]=3[CH:24]=2)=[CH:30][CH:31]=1

Participants

9

Reactant 4

HCID 4875Potassium IodideHCID 11430Potassium CarbonateHCID 706791-Butyne, 3-chloro-3-methyl-HCID 19788098HCID 19788098, compound

Product 1

HCID 150360116-(4-Methoxybenzylthio)-2,2-dimethyl-2H-1-benzopyran

Reagents, catalysts & solvents 4

HCID 887MethanolSolventHCID 3283Diethyl EtherSolventHCID 6569Methyl Ethyl KetoneSolventHCID 72391,2-DichlorobenzeneSolvent

Procedure

A solution of 73.84 g of 3-chloro-3-methyl-1-butyne in 225 ml of methanol, 11.95 g of potassium iodide and 99.50 g of potassium carbonate was added to the whole of the 4-(4-methoxybenzylthio)phenol prepared as described in step (a) above in 0.9 liters of methyl ethyl ketone, and the resulting mixture was heated under reflux for 40 hours in an atmosphere of nitrogen. At the end of this time, the reaction mixture was extracted with ethyl acetate, and the extract was washed with water and with a saturated aqueous solution of sodium chloride, in that order. It was then dried over anhydrous sodium sulfate, after which the solvent was removed by distillation under reduced pressure. The residue was purified by column chromatography through silica gel, using a 5:1 by volume mixture of cyclohexane and ethyl acetate as the eluent, to afford 67.68 g of an ether as an oil. A solution of the whole of this ether in 340 ml of o-dichlorobenzene was then heated under reflux for 2 hours in an atmosphere of nitrogen. At the end of this time, the reaction mixture was freed from the solvent by distillation under reduced pressure, and the residue was purified by column chromatography through silica gel, using a 20:1 by volume mixture of cyclohexane and ethyl acetate as the eluent. The eluted product was recrystallized from hexane to afford 48.74 g of the title compound, melting at 58°-59° C.

Workup

  1. customprepared
  2. temperaturethe resulting mixture was heated
  3. temperatureunder reflux for 40 hours in an atmosphere of nitrogen
  4. extractionAt the end of this time, the reaction mixture was extracted with ethyl acetate
  5. washthe extract was washed with water and with a saturated aqueous solution of sodium chloride, in that order
  6. dry with materialIt was then dried over anhydrous sodium sulfate
  7. customafter which the solvent was removed by distillation under reduced pressure
  8. customThe residue was purified by column chromatography through silica gel
  9. additionby volume mixture of cyclohexane and ethyl acetate as the eluent
  10. customto afford 67.68 g of an ether as an oil
  11. temperatureunder reflux for 2 hours in an atmosphere of nitrogen
  12. distillationAt the end of this time, the reaction mixture was freed from the solvent by distillation under reduced pressure
  13. customthe residue was purified by column chromatography through silica gel
  14. additionby volume mixture of cyclohexane and ethyl acetate as the eluent
  15. customThe eluted product was recrystallized from hexane

Sources & evidence

ORD record
ord-a2c37c0a73164ebd8e6d850fa75335e6
Source dataset
uspto-grants-1993_10
Patent number
US05254578

Reaction notes

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