Hydrochloric Acid → 6-Bromo-3-methyl-2-[3-(trifluoromethyl)phenyl]-4-quinolinecarboxylic acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

5-Bromoisatin (198 g, 788 mmol) was dissolved in ethanol (1.2 L) in a 6 L conical jacketed lab reactor equipped with a mechanical stirrer and an internal temperature probe. A solution of KOH (265 g, 4730 mmol) in water (0.480 L) was added slowly via addition funnel over ca. 1 hour, such that the vessel temperature was maintained at 20° C. 1-[3-(Trifluoromethyl)phenyl]-1-propanone (159 g, 788 mmol) was added in one portion and the reactor was heated to reflux for 1 h. The reaction mixture was cooled to 20° C. and acidified to pH˜2 by addition of 450 mL of concentrated HCl. An additional 1.5 L of 50% EtOH/H2O was added to facilitate filtration. The slurry was filtered and the filter cake was rinsed twice with 1 L portions of 50% EtOH/water. The solid was dried in vacuo to give 6-bromo-3-methyl-2-[3-(trifluoromethyl)phenyl]-4-quinolinecarboxylic acid (281.7 g, 87% yield) as a fine off-white solid. MS (m/z) 412.7 (M+H+).

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