Acetic Acid → 7-[(4'-Trifluoromethyl-biphenyl-2-carbonyl)-amino]-quinoline-3-carboxylic acid ethyl ester

Participants

Reaction Steps

A solution of 4′-trifluoromethyl-biphenyl-2-carboxylic acid (3-amino-4-formyl-phenyl)-amide (7 g, 18.2 mmol, 1 equiv) and 3-hydroxy-acrylic acid ethyl ester, sodium salt (2.52 g, 18.2 mmol, 1 equiv) in glacial acetic acid (70 mL, 10 volumes) was heated at 80° C. for 2 hours. Additional 3-hydroxy-acrylic acid ethyl ester, sodium salt (2.52 g, 18.2 mmol, 1 equiv) was added and the solution heated for 15 hours. Again, additional 3-hydroxy-acrylic acid ethyl ester, sodium salt (1.26 g, 9.1 mmol, 0.5 equiv) was added and the solution heated for another 4 hours. The reaction mixture was concentrated in vacuo. The residue was dissolved in EtOAc (300 mL) and the organic layer was washed with a saturated aqueous sodium carbonate solution (2×200 mL) and 1 N NaOH solution (200 mL). The combined aqueous layers were back extracted with ethyl acetate (200 mL). The combined organic layers were dried over sodium sulfate and treated with Darco G-60® (7 g). The solids were removed by filtration and the filtrate was concentrated to afford crude 7-[(4′-trifluoromethyl-biphenyl-2-carbonyl)-amino]-quinoline-3-carboxylic acid ethyl ester, which was used in the next step without further purification.

Provenance & Evidence