One-pot synthesis of fully substituted 1,3,4-oxadiazole derivatives from aromatic carboxylic acids, cyclobutanone and N-isocyaniminotriphenylphosphorane

Abstract

Reactions of N-isocyaniminotriphenylphosphorane with cyclobutanone in the presence of aromatic (or heteroaromatic) carboxylic acids proceeded smoothly at room temperature and in neutral conditions to afford sterically congested 1-(5-aryl-1,3,4-oxadiazol-2-yl)- 1-cyclobutanol derivatives in high yields. The reaction proceeded smoothly and cleanly under mild conditions and no side reactions were observed. The structures of the products were deduced from their IR, ^1HNMR, and ^{13}CNMR spectra, and mass spectrometry.