Four-Component Preparation of Disubstituted 1,3,4-Oxadiazoles from (N-isocyanimino)triphenylphosphorane, Phenylacetylenecarboxylic Acid, Biacetyl and Primary Amines
Four-Component Preparation of Disubstituted 1,3,4-Oxadiazoles from (N-isocyanimino)triphenylphosphorane, Phenylacetylenecarboxylic Acid, Biacetyl and Primary Amines
A simple method has been developed for four-component synthesis of disubstituted 1,3,4-oxadiazoles using (N-isocyanimino)triphenylphosphorane, a primary amine, a carboxylic acid and biacetyl in $CH_2Cl_2$ by the Ugi-4CR/aza-Wittig sequence at room temperature in excellent yields.