4-Piperidinecarboxylic acid → 5-Bromo-2-(piperidin-4-yl)benzo[d]oxazole

Participants

Reaction Conditions

Reaction Steps

2-amino-4-bromophenol (1.2 g, 5.8 mmol) and piperidine-4-carboxylic acid (0.74 g, 5.8 mmol) were dissolved in polyphosphoric acid (30 g). This mixture was heated at 190° C. for three and half hours. Reaction mixture cooled to rt and diluted with water (100 ml). Aqueous layer basified with sodium hydroxide pellets to pH 9. Work up (AcOEt/H2O) followed removal of AcOEt afforded the titled compound (0.8 g) as a pale-yellow gummy solid.

Provenance & Evidence