Hydrochloric Acid → 2,5-Bis(4-fluoroanilino)benzene-1,4-dicarboxylic acid

Participants

Reaction Steps

Dimethyl 2,5-bis{(4-fluorophenyl)amino}cyclohexa-1,4-diene-1,4-dicarboxylate (6.21 gm, 15 mmol), the sodium salt of 3-nitrobenzenesulphonic acid (3.6 gm; 16 mmol), ethanol (90 ml) and 1.0M sodium hydroxide (50 μl) were heated to reflux overnight under a nitrogen atmosphere. The bright yellow solution was allowed to cool and water (120 ml) was added. The mixture was acidified with conc. hydrochloric acid when a red solid precipitated out. This material was filtered off, washed with water and dried under vacuum over phosphorous pentoxide to give 5.6 gm (97%) of 2,5-bis{(4-fluorophenyl)amino}terephthalic acid λmax(ab) 295 nm, 380 nm. (0.1M sodium hydroxide)

Provenance & Evidence