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Ring closure reactions of 5‐azidopyrido[2,3‐ d ]pyrimidinetriones to isoxazolo‐ and oxadiazolopyrido[2,3‐ d ]pyrimidinetriones
Author(s) -
Van Tinh Dang,
Stadlbauer Wolfgang
Publication year - 2008
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570450621
Subject(s) - chemistry , regioselectivity , ring (chemistry) , azide , thermal decomposition , decomposition , differential scanning calorimetry , nitro , medicinal chemistry , closure (psychology) , organic chemistry , catalysis , physics , alkyl , thermodynamics , economics , market economy
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.