HCID 9794351, compound → 5,6,7,8-Tetrahydro-1,3-dimethyl-4H-cyclohepta[c]thiophen-4-one

HRID 1636571Notes

Reaction equation

HRID 1636571 reaction equation
[CH3:1][C:2]1[S:3][C:4]([CH3:14])=[CH:5][C:6]=1[CH2:7][CH2:8][CH2:9][CH2:10][C:11]([OH:13])=O>O>[CH3:1][C:2]1[S:3][C:4]([CH3:14])=[C:5]2[C:11](=[O:13])[CH2:10][CH2:9][CH2:8][CH2:7][C:6]=12

Participants

3

Reactant 1

HCID 9794351HCID 9794351, compound

Product 1

HCID 102197935,6,7,8-Tetrahydro-1,3-dimethyl-4H-cyclohepta[c]thiophen-4-oneYield 73%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

5-(2,5-Dimethyl-3-thiophenyl)pentanoic acid (12 g, 56.6 mmol) is heated in 30 g of polyphosphoric acid at 140° C. for 2 hr. After the reaction mixture is cooled to room temperature, water is added to dissolve the residual PPA. The mixture is then extracted with ether and the ether layer is washed with water, aqueous NaOH and again with water. The ether layer is then dried over sodium sulfate and the solvent evaporated under reduced pressure to yield 1,3-dimethyl-5,6,7,8-tetrahydro-4 H-cyclohepta[1,2-c]thiophen-4-one as a dark oil (8 g, 73%). 1H NMR (CDCl3) 2.70 (t, J=6.0 Hz, 2 H), 2.64 (dd, J=5.0, 7.0 Hz, 2 H), 2.55 (s, 3 H), 2.28 (s, 3 H), 1.79 (m, 4 H).

Workup

  1. dissolutionto dissolve the residual PPA
  2. extractionThe mixture is then extracted with ether
  3. washthe ether layer is washed with water, aqueous NaOH and again with water
  4. dry with materialThe ether layer is then dried over sodium sulfate
  5. customthe solvent evaporated under reduced pressure

Sources & evidence

ORD record
ord-92179e63157d4f6c8787df60c340245a
Source dataset
uspto-grants-2000_03
Patent number
US06034252

Reaction notes

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