Hydrochloric Acid → 3-Oxo-4-phenyl-3,4-dihydropyrido[2,3-b]pyrazine-2-carboxylic acid

Participants

Reaction Steps

10.74 g (36 mmol) of ethyl 3-oxo-4-phenyl-3,4-dihydropyrido[2,3-b]pyrazine-2-carboxylate was dissolved in acetic acid (270 mL), and 6 N hydrochloric acid (80 mL) was added thereto at room temperature. Then, the mixture was stirred overnight at room temperature. After confirming the completion of the reaction, the solvent was distilled off under reduced pressure, and water (100 mL) was added. The solid thus obtained was separated by filtration and dried, to obtain 6.50 g (yield: 67%) of 3-oxo-4-phenyl-3,4-dihydropyrido[2,3-b]pyrazine-2-carboxylic acid as pale brown crystals.

Provenance & Evidence