4-Aminobenzoic Acid → 4-(5-Methyl-benzooxazol-2-yl)-phenylamine

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-amino-p-cresol (1.5 g, 12 mmol), 4-aminobenzoic acid (1.67 g, 12 mmol) and 40 g polyphosphoric acid was heated at 190° C. under nitrogen for 6 h. The reaction mixture was cooled to room temperature and 300 ml water was added to the viscous liquid. The solid that precipitated was collected by filtration and dissolved in 200 ml ethyl acetate. The ethyl acetate solution was washed sequentially with 100 ml saturated aqueous sodium bicarbonate solution, 100 ml water and 100 ml brine, dried (anhydrous sodium sulfate) and concentrated under reduced pressure to yield the title compound as an off-white solid (2.43 g, 89% yield).

Provenance & Evidence