Sulfuric Acid → 5-(Carbomethoxy)-2,4,5,6-tetrahydro-cyclopenta[c]thiophene

HRID 2395981Notes

Reaction equation

HRID 2395981 reaction equation
[C:1]([CH:4]1[CH2:11][C:7]2=[CH:8][S:9][CH:10]=[C:6]2[CH2:5]1)([OH:3])=[O:2].[CH3:12]OC(OC)(C)C.S(=O)(=O)(O)O>CO>[C:1]([CH:4]1[CH2:11][C:7]2=[CH:8][S:9][CH:10]=[C:6]2[CH2:5]1)([O:3][CH3:12])=[O:2]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 64952,2-DimethoxypropaneHCID 158144134H,5H,6H-cyclopenta[c]thiophene-5-carboxylic acid

Product 1

HCID 158144145-(Carbomethoxy)-2,4,5,6-tetrahydro-cyclopenta[c]thiophene

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Dissolve 5-(carboxy)-2,4,5,6-tetrahydrocyclopenta[c]thiophene (3.95 g, 23.5mmol) in methanol (60 mL) and treat with dimethoxypropane (5.8 mL, 47 mmol)and sulfuric acid (0.8 mL). Stir at room temperature for 1 day. Evaporate the solvent in vacuo, dilute with methylene chloride (75 mL) and wash withsaturated sodium hydrogen carbonate (35 mL). Extract the aqueous phase withmethylene chloride (30 mL), wash combined organics with brine (30 mL) and dry (Na2SO4). Evaporate the solvent in vacuo and pass through aplug of silica gel to give 5-(carbomethoxy)-2,4,5,6-tetrahydro-cyclopenta[c]thiophene.

Workup

  1. customEvaporate the solvent in vacuo
  2. additiondilute with methylene chloride (75 mL)
  3. washwash withsaturated sodium hydrogen carbonate (35 mL)
  4. extractionExtract the aqueous phase withmethylene chloride (30 mL)
  5. washwash
  6. dry with materialdry (Na2SO4)
  7. customEvaporate the solvent in vacuo and pass through aplug of silica gel

Sources & evidence

ORD record
ord-592ea97a95b2480e9da15288078aea3b
Source dataset
uspto-grants-1996_02
Patent number
US05491142

Reaction notes

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