Hydrochloric Acid → 1-(4-tert-Butylphenyl)-2-carboxymethyl-5-(5-carboxypyridin-2-yloxy)-6-chloroindole-3-carboxylic acid

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Reaction Steps

A mixture of 1-(4-tert-butylphenyl)-6-chloro-5-(5-dimethylcarbamoyl-pyridin-2-yloxy)-2-ethoxycarbonylmethylindole-3-carboxylic acid ethyl ester (124 mg, 4.07 mmol; see step (c) above), NaOH (aq, 2 M, 1.0 mL) and dioxane (2.0 mL) was heated at reflux for 48 h, cooled, acidified to pH 2 with HCl (aq, 1 M) and extracted with EtOAc. The combined extracts were washed with H2O and brine, dried (Na2SO4), concentrated and purified by chromatography to give the title compound. Yield 40 mg (36%), mp 223-235° C.

Provenance & Evidence