Cs₂CO₃-Promoted Synthesis of Substituted Oxazoles

Significance

Reported is the cesium carbonate mediated synthesis of substituted oxazoles from the reaction of aromatic or cinnamic amides with 2,3-dibromopropene. Although the reaction was very successful with 2,3-dibromopropene, the ­results varied when substituted analogues were used. Thus, 1,2-dibromo-2-butene yielded the ­expected 5-ethyl-2-phenyloxazole (A), but 1,2-dibromo-2-octene and (2,3-dibromopropenyl)benzene both produced alkynes B as products.