Organic chemistry
Hamideh Javanbani; Ali Ramazani; Sang Woo Joo; Yavar Ahmadi; Vahid Azizkhani; Pegah Azimzadeh Asiabi
Volume 3, Issue 4, pp. 283-387, Serial No. 9 , October 2015, , Pages 310-322
Abstract
Reactions of N-isocyaniminotriphenylphosphorane with cyclopentanone have been studied in the presence of aromatic carboxylic acids and primary amines, proceeds smoothly at room temperature under neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives by an intramolecular Aza-Wittig ...
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Reactions of N-isocyaniminotriphenylphosphorane with cyclopentanone have been studied in the presence of aromatic carboxylic acids and primary amines, proceeds smoothly at room temperature under neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives by an intramolecular Aza-Wittig cyclization in CH2Cl2 in excellent yields. The structures of the products were deduced from their IR, Mass, ¹H NMR, and ¹³C NMR spectra. The reaction proceeds smoothly and cleanly under mild conditions and no side reactions were observed. The method offers a mild, simple, and efficient route for the preparation of fully substituted 1,3,4-oxadiazoles from cyclopentanone, primary amines, N-isocyaniminotriphenylphosphorane and aromatic carboxylic acids. Easy work-up, high yields and fairly mild reaction conditions make it a useful procedure in comparison to the modern synthetic methodologies.