Condensed Pyridazines. IV. Chemical Properties of 7-Methoxy-1-phenyl-1H-pyrazolo [3, 4-d] pyridazine 5-Oxide

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  • 縮合環を有するPyridazine誘導体に関する研究(第4報)7-Methoxy-1-phenyl-1H-pyrazolo[3,4-d]pyridazine 5-Oxideの化学的性質
  • 縮合環を有するPyridazine誘導体に関する研究-4-7-Methoxy-1-phenyl-1H-pyrazolo〔3,4-d〕pyridazine5-Oxideの化学的性質
  • シュクゴウカン オ ユウスル Pyridazine ユウドウタイ ニ カンスル

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Chemical properties of 7-methoxy-1-phenyl-1H-pyrazolo [3, 4-d] pyridazine 5-oxide (V) obtained in the reaction of 7-methoxy-1-phenyl-1H-pyrazolo [3, 4-d] pyridazine (IV) with m-chloroperbenzoic acid were studied. Compound V reacted with nucleophiles to give 4 (R2), 7 (R1)-disubstituted 1-phenyl-1H-pyrazolo [3, 4-d] pyridazine or the ring fission product, methyl 4 (R8)-substituted 1-phenyl-1H-pyrazole-5-carboxylate. The reaction of V with each of phosphoryl chloride and sulfuryl chloride gave VI (R2=Cl, R1=OCH3) and XI (R2=Cl, R1=OH). In the case of the reaction of V with tosyl chloride, XII (R3=CH (-Cl)-p-tosyl) was obtained together with VI and XI. The reaction of V with potassium hydroxide solution gave IX (R2=H, R1=OH, 5-oxide). The reaction of V with ethyl cyanoacetate in acetic anhydride gave XIII (R2=NC-CH-CO2C2H5, R1=OCH3). The Grignard reaction of V with methylmagnesium iodide and ethylmagnesium bromide gave XIVa (R2=CH3, R1=OCH3) and XIVb (R2=C2H5, R1=OCH3), respectively. Application of the Reissert reaction to V resulted in the formation of XVI (R3=CH=C (-OCH3)-(4-formyl-1-phenyl-1H-pyrazol-5-yl). The reaction of V with acetic anhydride afforded XVII (R2=OH, R1=OCH3), XVIII (R3=CH (-COCH3)-O-COCH3), and XIX ((R3=CH=)2). The reaction of V with acetyl chloride afforded XI, XXa (R3=CH (-COCH3)-R4, R4=4-chloro-6, 7-dihydro-7-oxo-1-phenyl-1H-pyrazolo [3, 4-d] pyridazin-6-yl) and XXI (R3=CH2-R4). A similar ring fission occurred in the reaction of V with benzoly chloride to afford XXb (R3=CH (-COPh)-R4), XXI, and XIX. The reaction of V with dimethyl acetylenedicarboxylate afforded 7-methoxy-1-phenyl-1H-pyrazolo [3, 4-d] pyridazinium 3-methoxy-1-methoxycarbonyl-2, 3-dioxopropylide (XXII), trimethyl 9-methoxy-1-phenyl-1H-pyrazolo [3, 4-d] pyrrolo [1, 2-b] pyridazine-4, 5, 6-tricarboxylate (XXIII), and methyl 5-methoxycarbonyl-6-methoxy-α-oxo-1-phenyl-1, 5H-cyclopenta [c]-pyrazol-5-ethanoate (XXIV). It is considered that the ring fission products are formed by the cleavage of pyridazine ring accompanied with the liberation of nitrogen.

Journal

  • YAKUGAKU ZASSHI

    YAKUGAKU ZASSHI 105 (2), 129-141, 1985

    The Pharmaceutical Society of Japan

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