title: Synthetic utilization of polynitroaromatic compounds. 6. Remarkable regioselectivity in nucleophilic displacement of aromatic nitro groups with amines.
abstract: 5,7-Dinitroquinazoline-4-ones undergo nucleophilic displacement of a nitro group with N-, S-, and O-nucleophiles. In contrast to previously studied dinitro-substituted benzoannulated five- and seven-membered heterocycles (where a high degree of selectivity was observed), these quinazolines mostly yield mixtures of regioisomeric substitution products. At the same time, primary and secondary amines react selectively to afford 5-aminoquinazolones (peri-substitution). A similar effect is observed for some other polynitroaromatic compounds with adjacent nitro and carbonyl groups. This phenomenon is attributed to a stabilization of the intermediate peri-sigma-complex by intramolecular hydrogen bond N(+)-H...O double bond C.
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry RAS, Leninsky Pr., 47 Moscow, 119991, Russia.
authors.forename: Konstantine A
authors.initials: KA
authors.lastname: Kislyi
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Samet
authors.forename: Yuri A
authors.initials: YA
authors.lastname: Strelenko
authors.forename: Victor V
authors.initials: VV
authors.lastname: Semenov