Four-component synthesis of 1,3,4-oxadiazole derivatives from N -isocyaniminotriphenylphosphorane, aromatic carboxylic acids, aromatic bis-aldehydes, and secondary amines

Authors : Ali Ramazani, Zahra Karimi, Ali Souldozi, Yavar Ahmadi

Pages : 81-91

Doi:10.3906/zoo-1212-31

View : 17 | Download : 8

Publication Date : 9999-12-31

Article Type : Makaleler

Abstract :The 1:1 iminium intermediate generated by the addition of a secondary amine to aromatic bis-aldehydes (isophthalaldehyde and terphthalaldehyde) is trapped by the N-isocyaniminotriphenylphosphorane in the presence of a aromatic carboxylic acid derivative, which leads to the formation of corresponding iminophosphorane intermediate. Then disubstituted 1,3,4-oxadiazole derivatives are formed via intramolecular aza-Wittig reaction of the iminophosphorane intermediates. The reactions were completed in neutral conditions at room temperature and the corresponding disubstituted 1,3,4-oxadiazole derivatives were produced in excellent yields.
Keywords : N-isocyaniminotriphenylphosphorane, aromatic carboxylic acid, aromatic bis-aldehydes, 1, 3, 4-oxadiazole, aza-Wittig reaction, secondary amine