Dichloromethane → 4-Hydroxy-2-(trifluoromethyl)quinoline-3-carboxylic acid

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Reaction Steps

A suspension of 4-hydroxy-2-trifluoromethyl-quinoline-3-carboxylic acid ethyl ester (5 g, 17.5 mmol) in 10% aqueous NaOH solution was heated at reflux for 2 h. After cooling, dichloromethane was added and the aqueous phase was separated and acidified with concentrated HCl to pH 4. The resulting precipitate was collected via filtration, washed with water and Et2O to provide 4-hydroxy-2-trifluoromethyl-quinoline-3-carboxylic acid (A-15) (3.6 g, 80%). 1H NMR (DMSO-d6) δ 8.18-8.21 (d, J=7.8 Hz, 1H), 7.92-7.94 (d, J=8.4 Hz, 1H), 7.79-7.83 (t, J=14.4 Hz, 1H), 7.50-7.53 (t, J=15 Hz, 1H); ESI-MS 257.0 m/z (MH+).

Provenance & Evidence