Synthetic Utilization of Polynitroaromatic Compounds. 6. Remarkable Regioselectivity in Nucleophilic Displacement of Aromatic Nitro Groups with Amines
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 yi...
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Veröffentlicht in: | Journal of organic chemistry 2008-03, Vol.73 (6), p.2285-2291 |
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Hauptverfasser: | , , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
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Zusammenfassung: | 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-σ-complex by intramolecular hydrogen bond N+H...OC. |
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ISSN: | 0022-3263 1520-6904 |
DOI: | 10.1021/jo702532x |