Aromatization of 1,4-DHPs have attracted considerable attention as they provide easy access to pyridine derivatives which show anti-hypoxic and anti-ischemic activities [1]. Various oxidants have been used for aromatization of 1,4-DHPs, however, most of these methods suffer from the use of strong oxidants and require intensive reaction conditions or the need for excess oxidant or long times and afford only poor to moderate yields of products [2]. Recently, We have synthesized trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxalane that is a cyclic gem-dihydroperoxides and used it as an effective oxidant in organic reactions [3]. For more stability of this peroxide, we have mixed it with urea (2 mmol urea and 1 mmol peroxide) and due to hydrogen bonding, urea-trans-3,5-dihydroperoxy-3,5-dimethyl-1,2dioxalane (UDHPDMDO) is stabilized (Scheme 1). In this work, we used UDHPDMDO for oxidative aromatization Of 1,4-dihydropyridines promoted by Ammonium iodide in water/MeCN in good yields within short times at room temperature.(scheme 2)
