Abstract
New approaches to the synthesis of oxazolo[5,4—c]pyridazine derivatives7 and15 starting from the substituted N-pyridazin-5-ylformamide oximes5 and13 are described. Under mild conditions the transformations of the amino or substituted amino group at position 2 of the oxazolo[5,4—c]pyridazine system were observed to give the compounds16 and17, while under more drastic reaction conditions the nucleophilic attack at position 2 followed by the ring opening of the oxazole part of the molecule was taking place to give the compounds18, 20, and21.
Zusammenfassung
Neue Synthesemöglichkeiten von Oxazolo[5,4—c]pyridazinen7 und15, ausgehend von substitutierten N-Pyridazin-5-ylformamid-oximen5 und13 werden beschrieben. Unter milden Reaktionsbedingungen trat Transformation der Amino- oder substituierten Aminogruppe an der Position 2 des Oxazolo[5,4—c]pyridazin-Systems unter Bildung der Verbindungen16 und17 ein, währenddessen unter drastischeren Reaktionsbedingungen ein nucleophiler Angriff am Kohlenstoff der Position 2, gefolgt von einer Ringöffnung des Oxazol-Teils des Moleküls zu Verbindungen18, 20 und21 führte.
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References
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The yields of purified products are given.
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Merslavič, M., Stanovnik, B. & Tišler, M. Transformations of N-heteroarylformamidines and N-heteroarylformamidine oximes new syntheses and transformations of oxazolo[5,4—c]pyridazines. Monatsh Chem 117, 221–230 (1986). https://doi.org/10.1007/BF00809442
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DOI: https://doi.org/10.1007/BF00809442