Alternative product of the cyclization of ortho-[O-(4-nitrobenzyl)]-substituted N-phenylquinone imine: structure and quantum chemical studies of the mechanism of formation

Abstract

N-(3′,5′-Di-tert-butyl-4′-hydroxyphenyl)-N-(2″-hydroxyphenyl)-4-nitrobenzamide was found to be an alternative product in the cyclization reaction of O-(4-nitrobenzyl) ether of N-phenylquinone imine proceeding through the formation of a benzoxazole ring. The structure of the product was established by ¹H and ¹³C NMR spectroscopy, high-resolution MS spectrometry, and X-ray diffraction analysis. Quantum chemical calculations of plausible mechanism of the formation of this compound were carried out.