Hydrochloric Acid → 5,5-dimethyl-4H,5H,6H-cyclopenta[b]thiophene-2-carboxylic acid

HRID 1918804Notes

Reaction equation

HRID 1918804 reaction equation
[CH3:1][C:2]1([CH3:15])[CH2:14][C:5]2[S:6][C:7]([C:9]([O:11]CC)=[O:10])=[CH:8][C:4]=2[CH2:3]1.C1COCC1.[OH-].[Li+].Cl>C(O)C.O>[CH3:1][C:2]1([CH3:15])[CH2:14][C:5]2[S:6][C:7]([C:9]([OH:11])=[O:10])=[CH:8][C:4]=2[CH2:3]1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 3939Lithium HydroxideHCID 8028TetrahydrofuranHCID 58043720Ethyl 5,5-Dimethyl-5,6-dihydro-4H-cyclopenta[b]thiophene-2-carboxylate

Product 1

HCID 580439285,5-dimethyl-4H,5H,6H-cyclopenta[b]thiophene-2-carboxylic acidYield 91%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Conditions

Temperature
60 °C

Procedure

In a 250-mL single-neck round-bottomed flask equipped with a magnetic stirrer and reflux condenser, 105b (4.00 g, 17.8 mmol) was dissolved in ethanol (50 mL). THF (50 mL), water (50 mL) and lithium hydroxide (854 mg, 35.6 mmol) were added, and the mixture was stirred at 60° C. for 4 h. After this time the reaction was cooled to room temperature and acidified with 2M hydrochloric acid to pH 1.5, and then extracted with ethyl acetate (2×200 mL). The organic layers were combined, washed with water (2×100 mL), followed by brine (100 ml) and dried over sodium sulfate. The drying agent was then separated by filtration. After evaporating the resulting filtrate, 105c was obtained in 91% yield (3.2 g) as a white solid: mp 170-172° C.; 1H NMR (300 MHz, CDCl3) d 12.77 (s, 1H), 7.46 (s, 1H), 2.71 (s, 2H), 2.53 (s, 2H), 1.20 (s, 6H); MS (ESI−) m/z 195.0

Workup

  1. customIn a 250-mL single-neck round-bottomed flask equipped with a magnetic stirrer
  2. temperaturereflux condenser
  3. temperatureAfter this time the reaction was cooled to room temperature
  4. extractionextracted with ethyl acetate (2×200 mL)
  5. washwashed with water (2×100 mL)
  6. dry with materialdried over sodium sulfate
  7. customThe drying agent was then separated by filtration
  8. customAfter evaporating the resulting filtrate

Sources & evidence

ORD record
ord-7e4bf436e6ac45698341f009a98609ff
Source dataset
uspto-grants-2013_12
Patent number
US08618107B2

Reaction notes

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