p-Toluenesulfonic acid → 4-Bromo-2-[(2,4-difluorobenzylidene)amino]-5-fluorophenol

Participants

Reaction Steps

A solution of 2-amino-4-bromo-5-fluorophenol (10.1 g, 49 mmol), 2,4-difluorobenzaldehyde (5.36 mL, 49 mmol) and p-toluenesulfonic acid (100 mg, 0.52 mmol) in toluene (250 mL) was heated to reflux in a Dean-Stark apparatus for 0.5 h and then allowed to cool to ambient temperature. After adding triethylamine (1 mL) the reaction mixture was concentrated under reduced pressure to give the crude compound which was used without further purification. (16.1 g, 99%). 1H-NMR (400 MHz, CDCl3) 6.83 (d, J=10.2, 1H), 6.93 (m, 1H), 7.01 (m, 1H), 7.49 (d, J=7.6, 1H), 8.13 (m, 1H), 8.85 (s, 1H).

Provenance & Evidence