4-Piperidinecarboxylic acid → 2-(Piperidin-4-yl)-1,3-benzoxazole

Participants

Reaction Steps

A mixture of 2-aminophenol (20 g, 183 mmol), isonipecotic acid (23.7 g, 1 mol. equiv.) and polyphosphoric acid (50 ml) was heated together for 2 hours with stirring. The reaction mixture was cooled, poured onto ice (400 g) and solid sodium hydroxide (85 g) added until the solution achieved pH8. The solid was filtered off, slurried in water (500 ml) and filtered to give the title compound (4.5 g).

Provenance & Evidence