5-ethyl-2,3-dihydro-1H-indole-2,3-dione → 3-Amino-2-[1.1'-biphenyl]-4-yl-6-ethyl-4-quinolinecarboxylic acid

Participants

Reaction Steps

A 12.63 g portion of 2-amino-4'-phenylacetophenone, hydrochloride was dissolved in a mixture of 168 ml of absolute ethanol:water (1:1) and 40 ml of tetrahydrofuran. This solution was kept warm and with stirring, added dropwise to the 5-ethylisatin solution over 2 hours. The mixture was refluxed for 2 hours, then the solvent was distilled off at 85° C. and the reaction cooled for 1 hour. The red solids were collected, stirred with 2 liters of water for 1.5 hours and then filtered. The filtrate was acidified to pH 5 with glacial acetic acid. The resulting yellow solids were collected and dried, giving 4.47 g of the desired product, mp 240°-241° C.

Provenance & Evidence