Comportement de quelques Arylbenzo[b]-furannes sous l'Impact électronique

Unexpected detection of 3-aroylbenzofuran side products in the preparation of 2-arylbenzofurans: Identification, characterization, and comparison with chalcone's fragmentation patterns using EI/MSn

A gas chromatography-mass spectrometry study of the intramolecular Wittig reaction revealed, together with the expected 2-phenylbenzofuran, the formation of an unexpected side product that has not been reported until now. This study reports the identification of the by-product, ie, the 3-benzoyl-2-phenylbenzofuran, on the base of its mass spectrometric behaviour using a combination of electron ionization, exact mass measurement, multiple stage mass spectrometry, and labelled compounds. This study reports the common fragmentation pathways and discusses possible fragment structures of characteristic ions from a series of 3-aroyl-2-arylbenzofuran derivatives obtained as by-product under Wittig conditions. Emphasis is laid on the formation and structure investigation of the [M-H]⁺ and [M-OH]⁺ ions. Our results showed interesting analogies with the mass spectrometric behaviour of chalcones.