Water → 4-(2-Isopropoxy-3-methyl-benzoylamino)-tetrahydro-thiopyran-4-carboxylic acid

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Reaction Steps

The mixture of 4-(2-isopropoxy-3-methyl-benzoylamino)-tetrahydro-thiopyran-4-carboxylic acid methyl ester (28) (75 mg, 0.21 mmol) and KOH (500 mg, 8.9 mmol) is dissolved in EtOH (5 mL) and water (0.5 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 came out of the water. The precipitate is filtered to give a pure product (29) as a pale yellow solid (68 mg, 94%).

Provenance & Evidence