Hydrochloric Acid → Ethyl 4-hydroxy-2-oxo-1-{[phenylmethylene]amino}-1,2-dihydroquinoline-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

Methyl 2-[2-benzylidene-1-(3-ethoxy-3-oxopropanoyl)hydrazino]benzoate (5.17 g, 14.59 mmol) in ethanol (100 mL) was reacted with sodium ethoxide (21% by weight in ethanol, 5.50 mL, 14.60 mmol) at 25° C. then heated at 50° C. for 1 hour. After cooling to 25° C., the reaction mixture was poured into water, acidified to pH 4 with 1M hydrochloric acid and extracted with ethyl acetate. The organic layer was dried over anhydrous sodium sulfate, filtered and the solvent removed under vacuum to give ethyl 4-hydroxy-2-oxo-1-{[phenylmethylene]amino}-1,2-dihydroquinoline-3-carboxylate (4.51 g, 96%). MS (DCI) m/z 323 (M+H)+. 1H NMR (300 MHz, DMSO-d6) ppm 3.73 (s, 3 H) 7.21 (m, 1 H) 7.56 (m, 5 H) 7.95 (m, 2 H) 8.03 (d, J=7.72 Hz, 1 H) 9.08 (s, 1 H).

Provenance & Evidence