1,1'-Biphenyl, mixt. with 1,1'-oxybis(benzene) → Ethyl 8-chloro-4-oxo-5-(trifluoromethyl)-1,4-dihydroquinoline-3-carboxylate

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Reaction Steps

6 mL of Dowtherm was added to a long-neck 25 mL flask, fitted with a reflux condenser. The Dowtherm was heated to 200° C. and degassed for 20 minutes. Diethyl 2-((2-chloro-5-(trifluoromethyl)phenylamino)methylene)malonate (1 g, 2.73 mmol) was then added and the solution was then heated to reflux for 2.5 h under N2. The reaction mixture was cooled after 2.5 h, then diluted with hexane (12 mL) to produce a fine, light brown precipitate. The reaction mixture was filtered, and the precipitate washed with hexane until the color was removed. The product was air dried to obtain ethyl 8-chloro-4-oxo-5-(trifluoromethyl)-1,4-dihydroquinoline-3-carboxylate as a light brown solid (0.57 g, 65%). 1H NMR (400 MHz, DMSO-d6) δ 11.91 (s, 1H), 8.39 (s, 1H), 8.06 (d, J=8.3 Hz, 1H), 7.81 (d, J=8.4 Hz, 1H), 4.24 (q, J=7.1 Hz, 2H), 1.29 (t, J=7.1 Hz, 3H).

Provenance & Evidence