Sodium Hydroxide → 3-Amino-6-chloro-2-(2'-fluoro[1,1'-biphenyl]-4-yl)-4-quinolinecarboxylic acid

Participants

Reaction Steps

To a stirred suspension of 4.54 g of 5-chloroisatin in 40 ml of water was added a solution of 5.62 g of sodium hydroxide in 20 ml of water. To the resulting solution at 85°-90° C. was added dropwise over 2 hours, a warm solution of 9.3 g of 2-amino-1-(2'-fluoro[1,1'-biphenyl]-4-yl)ethanone, hydrochloride in 70 ml of water, 70 ml of ethanol and 30 ml of tetrahydrofuran. This mixture was stirred at reflux for 2 hours then the ethanol was distilled off. The reaction was cooled in an ice bath, the solid collected and washed with water. This solid was stirred in 800 ml of water for 2 hours and then filtered. The filtrate was acidified to pH 4-5 with acetic acid. The resulting solid was collected, washed with water and dried, giving 6.6 g of the desired product as a yellow solid, mp 247°-249° C.

Provenance & Evidence