Water → 5-(2-Isopropoxy-3-methyl-benzoylamino)-1,3-dimethyl-5,6-dihydro-4H-cyclopenta[c]thiophene-5-carboxylic acid

Participants

Reaction Steps

The mixture of 5-(2-isopropoxy-3-methyl-benzoylamino)-1,3-dimethyl-5,6-dihydro-4H-cyclopenta[c]thiophene-5-carboxylic acid ethyl ester (88) (448 mg, 1.08 mmol) and KOH (1 g, 18 mmol) is dissolved in EtOH (8 mL) and water (1 mL) under a water bath. The water bath is removed when KOH is completely dissolved and the resulting reaction solution is stirred at RT for 8 h. After concentration in vacuo, the residue is dissolved in water (20 mL) and acidified with conc. HCl until no more precipitate formed. The precipitate is filtered to give a pure product (89) as a brown solid (360 mg, 86%).

Provenance & Evidence