Hydrochloric Acid → 4H,5H,6H-cyclopenta(b)thiophene-2-carboxylic acid

HRID 2178982Notes

Reaction equation

HRID 2178982 reaction equation
[S:1]1[C:5]([C:6]([O:8]C)=[O:7])=[CH:4][C:3]2[CH2:10][CH2:11][CH2:12][C:2]1=2.C1COCC1.CCO.O.[Li+].[OH-].Cl>O>[S:1]1[C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]2[CH2:10][CH2:11][CH2:12][C:2]1=2

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 3939Lithium HydroxideHCID 5061470methyl 5,6-dihydro-4H-cyclopenta[b]thiophene-2-carboxylateHCID 18504229Ethanol tetrahydrofuran water

Product 1

HCID 7709804H,5H,6H-cyclopenta(b)thiophene-2-carboxylic acidYield 91%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
50 °C

Procedure

To a solution of methyl 4H,5H,6H-cyclopenta[b]thiophene-2-carboxylate (1 g, 5.49 mmol, 1.00 equiv) in a THF/EtOH/water (10/10/10 mL) mixture was added LiOH (660 mg) at room temperature. The resulting solution was stirred for 3 h at 50° C. in an oil bath and then diluted with 20 mL of water. The pH value of the solution was adjusted to 5 with 2 M aqueous hydrochloric acid. The precipitate was collected by filtration and dried in an oven under reduced pressure to give the desired 4H,5H,6H-cyclopenta[b]thiophene-2-carboxylic acid (0.84 g, 91%) as an off-white solid.

Workup

  1. filtrationThe precipitate was collected by filtration
  2. customdried in an oven under reduced pressure

Sources & evidence

ORD record
ord-a57f410a6c644dd7a15ad29246d692f8
Source dataset
uspto-grants-2015_06
Patent number
US09067948B2

Reaction notes

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