The synthesis and the pharmacological evaluation of benzisothiazole and benzimidazole tetrazolyl- and carboxyl-derivatives 1-6 are described. Structural modification was aimed at investigating the influence of two isosteric substituents (tetrazolyl- and carboxyl-) on the title benzofused heterocycles. The antiphlogistic, antipyretic and analgesic activities have been investigated in in vivo experimental models. Additional investigations have been performed in vitro to study the antiplatelet and spasmolytic activity of the compounds synthetized. All the compounds produced peripheral analgesic effects, but were less effective in hot plate test. The tetrazole and the carboxylic benzisothiazole derivatives 2 and 3 proved to be the most effective drugs within the series, exhibiting maximal inhibition of writhes with a potency 3-fold higher than that of acetaminophen. Only compound 5 provided indication for a central analgesic activity since it was active in hot plate test although with a low potency. The findings obtained in these in vivo and in vitro studies indicate that these compounds do not share the same mechanism of action of acetaminophen. All of the compounds under study present lower acute toxicity than acetaminophen when orally administered in mice. (C) 2002 Published by Editions scientifiques et medicales Elsevier SAS.
Highly efficient synthesis of 1- and 5-substituted 1H-tetrazoles using chitosan derived magnetic ionic liquid as a recyclable biopolymer-supported catalyst
作者:Ali Khalafi-Nezhad、Somayeh Mohammadi
DOI:10.1039/c3ra23107k
日期:——
A general method for the efficient synthesis of 1- and 5-substituted1H-tetrazoles from nitriles and amines is described using chitosan supported magnetic ionic liquid nanoparticles (CSMIL) as a novel heterogeneous catalyst. The application of this catalyst allows the synthesis of a variety of tetrazoles in high yields at low temperature. This new magnetic catalyst has been prepared from chitosan (the