New bispyridinium dibromides based on the 1,4-dihydropyridine (1,4-DHP) cycle were synthesised in the reaction between 4-pyridyl-1,4-DHP derivatives and propargyl bromide. It has been shown that variation of the substituent position on the pyridine as well as small changes in the electronic nature of the 1,4-DHP cycle as a result of the substituent nature at the 3 and 5 positions do not affect the course of the reaction and in all cases the corresponding bispyridinium dibromides 4a-e were formed. The antiradical activity, using 1,1-diphenyl-2-picrylhydrazine as a free radical scavenger, and the reducing capacity using phosphomolybdenum complexes have been evaluated for the newly synthesised compounds 4a-e. It has been shown that all tested 1,4-DHP bispyridinium dibromides 4a-e possess reducing capacity and antiradical properties. Moreover, the reducing capacity results could be explained by the influence of the electronic nature of the substituent at the 3 and 5 positions of the 1,4-DHP cycle.
Field of Science*
- 1.4 Chemical sciences
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