Quinoxalines XIV. Synthesis, 1 H, 13 C, 15 N NMR spectroscopic, and quantum chemical study of 1H-pyrazolo [3, 4-b] quinoxalines (flavazoles)

M Heydenreich, A Koch, G Sarodnick, E Kleinpeter

Index: Heydenreich, Matthias; Koch, Andreas; Sarodnick, Gerhard; Kleinpeter, Erich Tetrahedron, 2005 , vol. 61, # 9 p. 2373 - 2385

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Citation Number: 5

Abstract

The synthesis of a series of 1H-pyrazolo [3, 4-b] quinoxalines (flavazoles) by acylation, alkylation, halogenation, and aminomethylation of the parent compound is reported and their structure is investigated by 1H, 13C, and 15N NMR spectroscopy. The restricted rotation about the partial C, N double bond of the N-acyl derivatives 7–10 is studied by dynamic NMR spectroscopy and the barriers to rotation are determined. In order to assign ...