Nitric Acid → 5-Hydroxy-6-nitro-2-trifluoromethyl-quinoline-7-carboxylic acid methyl ester

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Reaction Steps

5-Hydroxy-2-trifluoromethyl-quinoline-7-carboxylic acid methyl ester (46.0 g, 169.63 mmol) is dissolved in 200 ml of concentrated (97%) sulphuric acid at 0-5° C. To this cooled solution is added drop wise fuming (100%) nitric acid (7 ml, 10.69 g, 169.63 mmol). After the addition is complete, the reaction mixture is allowed to warm to room temperature. TLC analysis (4:1 hexane:ethyl acetate) after 30 min shows reaction completion. The reaction mixture is slowly poured onto an ice/water mixture (ca. 2 l), and the crystals then filtered at the pump, thoroughly washed with water, and dried in vacuo. This affords the title compound (47.0 g, 87.6%) as pale yellow crystals.

Provenance & Evidence