One-pot, four-component synthesis of fully substituted 1,3,4-oxadiazole derivatives from (Isocyanoimino)triphenylphosphorane, a primary amine, an aromatic carboxylic acid, and chloroacetone

چکیده مقاله

The 1:1 imine intermediate 7 generated by the addition of a primary amine 2 to chloroacetone (1) is trapped by (isocyanoimino)triphenylphosphorane (4) in the presence of an aromatic carboxylic acid 3 and leads to the formation of the corresponding iminophosphorane intermediate 9 (Schemea 2). The 1,3,4-oxadiazole derivatives 5 are then formed via an intramolecular aza-Wittig reaction of the iminophosphorane intermediate 9. The reactions were completed under neutral conditions at room temperature. The fully substituted 1,3,4-oxadiazole derivatives 5 were produced in high yields (Table). © 2011 Verlag Helvetica Chimica Acta AG, Zürich, Switzerland.