Four-Component Synthesis of Disubstituted 1,3,4-Oxadiazoles from N-Isocyaniminotriphenylphosphorane, Phenylacetylenecarboxylic Acid, Chloroacetone Derivatives, and Primary Amines

Abstract

The 1:1 imine intermediate generated by the addition of primary amine to chloroacetone derivatives is trapped by N-isocyaniminotriphenylphosphorane in the presence of phenylacetylenecarboxylic acid, leading to the formation of the corresponding iminophosphorane intermediate. Disubstituted 1,3,4-oxadiazole derivatives are formed via intramolecular aza-Wittig reaction of the iminophosphorane intermediate. The reactions were completed in neutral conditions at room temperature. The disubstituted 1,3,4-oxadiazole derivatives were prepared in excellent yields.

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GRAPHICAL ABSTRACT

Keywords:

• Aza-Wittig reaction
• chloroacetone derivatives
• N-isocyaniminotriphenylphosphorane
• 1,3,4-oxadiazole
• phenylacetylenecarboxylic acid
• primary amine

ACKNOWLEDGMENT

This research was supported by the Iran National Science Foundation (INSF).