Diethyl (ethoxymethylene)malonate → Ethyl 7-chloro-4-oxo-1,4-dihydroquinoline-3-carboxylate

Participants

Reaction Steps

3-Chloroaniline (5.0 g) and diethyl ethoxymethylenemalonate (10.2 g) were reacted in the same manner as in Experimental Example 1 to obtain 7-chloro-3-ethoxycarbonyl-4(1H)-quinolone (13.0 g). This compound (5.0 g) was hydrolyzed in the same manner as in Experimental Example 2 to obtain a carboxylic acid (4.2 g). This acid derivative (4.2 g) was dissolved in pyridine (40 ml), piperazine (5.2 g) was added to the solution, and the mixture was heated under reflux for 48 hours. The solvent was removed by distillation, and the residue was purified by column chromatography (Wako Gel C-200, 100 g). Elution with a mixed solvent of chloroform (90 parts) and methanol (10 parts) gave 7-piperazinyl-4(1H)-quinolone (compound 67, 3.3 g).

Provenance & Evidence