Toluene → 5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophen-4-one

HRID 650591Notes

Reaction equation

HRID 650591 reaction equation
[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[CH2:6][CH2:7][CH2:8][CH2:9][C:10]([OH:12])=O.C1(C)C=CC=CC=1.FC(F)(F)C(OC(=O)C(F)(F)F)=O.C(=O)([O-])O.[Na+]>CCOC(C)=O>[O:12]=[C:10]1[C:3]2[CH:4]=[CH:5][S:1][C:2]=2[CH2:6][CH2:7][CH2:8][CH2:9]1

Participants

6

Reactant 4

HCID 1140TolueneHCID 9845Trifluoroacetic anhydrideHCID 1523245-(2-Thienyl)valeric acidHCID 516892Sodium Bicarbonate

Product 1

HCID 123415575,6,7,8-tetrahydro-4H-cyclohepta[b]thiophen-4-oneYield 34.5%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

To a mixture of 5-(2-thienyl)pentanoic acid (5.04 g) and toluene (50 ml) was dropwise added trifluoroacetic anhydride (6.95 ml) over 1 minute with ice-water cooling. The reaction mixture was stirred at room temperature (r.t.) overnight, and was poured into a mixture of a saturated aqueous solution of sodium hydrogen carbonate (NaHCO3) and AcOEt. The organic layer was washed with water and brine, and dried over MgSO4, and evaporated. The resulting oil was purified by chromatography on silica gel (SiO2) (20% AcOEt in n-hexane as eluent). The fractions including the object compound were combined and evaporated to give 4-oxo-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene (1.57 g) as an oil.

Workup

  1. customover 1 minute
  2. washThe organic layer was washed with water and brine
  3. dry with materialdried over MgSO4
  4. customevaporated
  5. customThe resulting oil was purified by chromatography on silica gel (SiO2) (20% AcOEt in n-hexane as eluent)
  6. customevaporated

Sources & evidence

ORD record
ord-276b32f8e198470cbe1944636cea0afa
Source dataset
uspto-grants-2001_08
Patent number
US06274619B1

Reaction notes

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