Novel Transition-Metal Catalyzed Rearrangement of Piroxicam, a Benzothiazine Carboxamide Derivative = Benzothiazine 유도체인 Piroxicam의 분자 재배열을 야기시키는 전이금속-촉배화 반응

다국어 초록 (Multilingual Abstract)

As part of a program to evaluate the possible role of metal ions in the phototoxicity of piroxicam in the biological systems, the interactions of the various transition metal ions with piroxicam (4-hydroxy-2-methyl-N-2-pyridyl-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide)have been studied by the spectroscopic methods. The absorption band of piroxicam disappears in the presence of Zn^2+ and Cu^2+ by first-order kinetics, indicating that the structural change of piroxicam is catalyzed by the metal ions. The metal-catalyzed reaction product has been isolated and its structure has been identified by IR, NMR, and mass spectroscopic methods. These results indicate that Zn^2+ and Cu^2+ ions are highly effective in promoting a rearrangement of the piroxicam molccule.