In the last few years, increasing attention has been paid to the imidazo[1,5-a]pyridine nucleus^[1]. The imidazo[1,5-a]pyridines are an important class of heterocyclic compounds owing to their photophysical and biological properties. They have found utility in a number of areas of research including potential applications in organic light-emitting diodes (OLED) and thin-layer field effect transistors (FET). In addition they have been investigated in a wide range of potential pharmaceutical applications, including HIV-protease inhibitors, and Thromboxane A2 synthesis inhibitors^[2-6].

Pyridazine is one of the important six-membered ring systems and an important chemical entity with the potentials to obtain its analogs with more advanced pharmacological effects^[1]. As so far, pyridazines and their oxo-derivatives are known as the privileged heteroaromatic skeleton due to the important bioactivities associated with these compounds involving antihypertensive, antifungal, antiviral, anti-inflammatory, anticancer, anti-diabetic and antimicrobial activities^[2-7]. Regarding this fact, there has been extensive attention toward the synthesis of novel compounds containing pyridazine moiety and evaluation their bioactivities^[2].