What is "oxazole"

n. (context organic compound English) A five-membered heterocycle having three carbon atoms, one oxygen atom, one nitrogen atom and two double bonds; the 1,3- isomer is aromatic

Oxazole is the parent compound for a vast class of heterocyclic aromatic organic compounds. These are azoles with an oxygen and a nitrogen separated by one carbon. Oxazoles are aromatic compounds but less so than the thiazoles. Oxazole is a weak base; its conjugate acid has a pK of 0.8, compared to 7 for imidazole.