Reaction of pyrido[2,1-a]isoindole with 1,4-naphtoquinone and study of the product by spectroscopic methods

Yegorova, T., Barnych, B., Voitenko, Z. (2016). Reaction of pyrido[2,1-a]isoindole with 1,4-naphtoquinone and study of the product by spectroscopic methods. French-Ukrainian Journal of Chemistry, 4(2), 33–39. https://doi.org/10.17721/fujcV4I2P33-39

Key role of the electronic structure of condensed isoindols in the way of the rearrangement was shown. Influence of the dienophile manifests in the requirement of the cyclic form of the dienophile itself. In the reaction of pyrido[2,1-a]isoindole with naphtoquinone rearrangement product of the first type was obtained and its structure was proven by spectral methods. Spectral criteria for the rearranged adducts of the first type for the pyrido[2,1-a]isoindole in the 13C NMR spectra were established. Products of reactions with naphthoquinone, 4-fluoro-, 2,5-difluorophenylmaleimides were isolated and characterized: (2E)-2-[(1,4-dihydroxy-2-naphthyl)(2-pyridin-2-ylphenyl)methylene]-4-hydroxynaphthalen-1(2H)-one, (3E)-1-(4-fluorophenyl)-3-[[1-(4-fluorophenyl)-2,5-dioxopyrrolidin-3-yl](2-pyridin-2-ylphenyl)methylene]pyrrolidine-2,5-dione, (3E)-1-(2,4-difluorophenyl)-3-[[1-(2,4-fluorophenyl)-2,5-dioxopyrrolidin-3-yl](2-pyridin-2-ylphenyl)methylene]pyrrolidine-2,5-dione.