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Ring closure reactions of 5-azidopyrido[2,3-d]pyrimidinetriones to isoxazolo- and oxadiazolopyrido[2,3-d]pyrimidinetriones

✍ Scribed by Dang Van Tinh; Wolfgang Stadlbauer

Publisher: Journal of Heterocyclic Chemistry
Year: 2008
Tongue: English
Weight: 227 KB
Volume: 45
Category: Article
ISSN: 0022-152X
DOI: 10.1002/jhet.5570450621

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✦ Synopsis

Abstract

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Thermal decomposition of 5‐azidopyrido[2,3‐d]pyrimidines 2 and 7 having reactive ortho‐substituents such as a formyl or a nitro group yielded isoxazolo[3′,4′:4,5]pyrido[2,3‐d]pyrimidines 3 or oxadiazolo‐[3′,4′:4,5]pyrido[2,3‐d]pyrimidines 9. The reaction conditions of the azide decomposition were studied by differential scanning calorimetry (DSC). In addition, desoxygenation of N‐oxides 9 to oxadiazoles 10 and regioselective reduction of azides 7 to amines 8 were studied.

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