Hydrochloric Acid → 2,2-Dimethyl-6-pentafluoroethylthio-2H-1-benzopyran

HRID 1656466Notes

Reaction equation

HRID 1656466 reaction equation
[SH:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][C:9]([CH3:12])([CH3:11])[CH:8]=[CH:7][C:6]=2[CH:13]=1.[H-].[Na+].[F:16][C:17](I)([F:22])[C:18]([F:21])([F:20])[F:19].Cl>CN(C)C=O>[CH3:12][C:9]1([CH3:11])[CH:8]=[CH:7][C:6]2[CH:13]=[C:2]([S:1][C:17]([F:22])([F:16])[C:18]([F:21])([F:20])[F:19])[CH:3]=[CH:4][C:5]=2[O:10]1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 9636IodopentafluoroethaneHCID 24758Sodium hydrideHCID 15036012HCID 15036012, compound

Product 1

HCID 197881122,2-Dimethyl-6-pentafluoroethylthio-2H-1-benzopyranYield 82%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

A solution of 1.463 g of 6-mercapto-2,2-dimethyl-2H-1-benzopyran (prepared as described in Preparation 6) in 15 ml of dimethylformamide was added dropwise, whilst ice-cooling, to a suspension of 0.366 g of sodium hydride (as a 55% w/w dispersion in mineral oil) in 15 ml of dimethylformamide under an atmosphere of nitrogen. After the reaction mixture had been stirred for 15 minutes, 5.53 g of perfluoroethyl iodide were added to it. The reaction mixture was then stirred whilst ice-cooling for 1 hour and then at room temperature for 2 hours. At the end of this time, the reaction mixture was poured into 150 ml of dilute aqueous hydrochloric acid and extracted with ethyl acetate. The extract was washed with water, with an aqueous solution of sodium hydrogencarbonate and with a saturated aqueous solution of sodium chloride, in that order, after which it was dried over anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure, and the resulting residue was purified by column chromatography through silica gel, using a 20:1 by volume mixture of cyclohexane and ethyl acetate as the eluent, to afford 1.935 g of the title compound as an oil.

Workup

  1. stirringThe reaction mixture was then stirred whilst ice-
  2. temperaturecooling for 1 hour
  3. waitat room temperature for 2 hours
  4. extractionextracted with ethyl acetate
  5. washThe extract was washed with water, with an aqueous solution of sodium hydrogencarbonate and with a saturated aqueous solution of sodium chloride, in that order
  6. dry with materialafter which it was dried over anhydrous sodium sulfate
  7. customThe solvent was removed by distillation under reduced pressure
  8. customthe resulting residue was purified by column chromatography through silica gel
  9. additionby volume mixture of cyclohexane and ethyl acetate as the eluent

Sources & evidence

ORD record
ord-7b57120e793c4f27ada3360c20a1ef07
Source dataset
uspto-grants-1993_10
Patent number
US05254578

Reaction notes

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