Dimethyl Sulfide → trans-6-pentafluoroethyl-2,2-bisfluoromethyl-3,4-dihydro-4-(3-oxo-cyclopent-1-enyloxy)-2H-1-benzopyran-3-ol

HRID 977614Notes

Reaction equation

HRID 977614 reaction equation
[C:1]1(=[O:7])[CH2:5][CH2:4][C:3](=[O:6])[CH2:2]1.[H-].[Na+].CSC.[O:13]1[CH:19]2[CH:14]1[C:15]([CH2:33][F:34])([CH2:31][F:32])[O:16][C:17]1[CH:23]=[CH:22][C:21]([C:24]([F:30])([F:29])[C:25]([F:28])([F:27])[F:26])=[CH:20][C:18]=12.S(=O)(=O)(O)O>O1CCCC1.[Cu]Br.O>[F:30][C:24]([F:29])([C:21]1[CH:22]=[CH:23][C:17]2[O:16][C:15]([CH2:33][F:34])([CH2:31][F:32])[C@@H:14]([OH:13])[C@H:19]([O:6][C:3]3[CH2:4][CH2:5][C:1](=[O:7])[CH:2]=3)[C:18]=2[CH:20]=1)[C:25]([F:28])([F:27])[F:26]

Participants

9

Reactant 5

HCID 1068Dimethyl SulfideHCID 1118Sulfuric AcidHCID 24758Sodium hydrideHCID 774661,3-CyclopentanedioneHCID 158717923,4-epoxy-6-pentafluoroethyl-2,2-bisfluoromethyl-3,4-dihydro-2H-1-benzopyran

Product 1

HCID 86750614trans-6-pentafluoroethyl-2,2-bisfluoromethyl-3,4-dihydro-4-(3-oxo-cyclopent-1-enyloxy)-2H-1-benzopyran-3-olYield 3.4%

Reagents, catalysts & solvents 3

HCID 24593copper(I) bromideCatalystHCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-20 °C

Procedure

In 40 ml of tetrahydrofuran was dissolved 0.36 g of cyclopentan-1,3-dione and 0.13 g of sodium hydride (60%) was added thereto under nitrogen stream with cooling at -20° C. after the mixture was stirred at room temperature for 15 minutes, 0.72 g of a complex of copper (I) bromide and dimethyl sulfide was added. To the reaction mixture was added 0.92 g of 3,4-epoxy-6-pentafluoroethyl-2,2-bisfluoromethyl-3,4-dihydro-2H-1-benzopyran dissolved in 10 ml of tetrahydrofuran. The mixture was stirred for 6 days. To the mixture were added water and a small amount of concentrated sulfuric acid. The mixture was extracted with methylene chloride and the organic layer was washed with water and dried. The solvent was distilled off and the resultant residue was purified using silica gel column chromatography (developing solution, MeOH:CH2Cl2 =1:99) and another silica gel column chromatography (developing solution, AcOEt:hexane=1:1) to obtain 0.04 g of trans-6-pentafluoroethyl-2,2-bisfluoromethyl-3,4-dihydro-4-(3-oxo-cyclopent-1-enyloxy)-2H-1-benzopyran-3-ol represented by the following formula having a melting point of 165°-167° C.

Workup

  1. additionwas added
  2. stirringThe mixture was stirred for 6 days
  3. extractionThe mixture was extracted with methylene chloride
  4. washthe organic layer was washed with water
  5. customdried
  6. distillationThe solvent was distilled off
  7. customthe resultant residue was purified

Sources & evidence

ORD record
ord-2cc87fa2783a43f4b92ffd953cef6511
Source dataset
uspto-grants-1997_03
Patent number
US05614633

Reaction notes

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