Pyridazine, also known as o-diazobenzene, is a six-membered heterocyclic compound containing two nitrogen heteroatoms in the 1 and 2 positions with a special structure and a wide biological activity. Pyridazine is more and more popular in drug development, and a variety of pyridazine drugs have been developed and marketed. From the perspective of the therapeutic field, pyridazine drug molecules are mainly used for tumor treatment, but also involve in many therapeutic fields such as inflammation, hypertension and cardiovascular disease. With the increase and in-depth of research, pyridazine drugs will play more roles in the treatment of diseases.
Quinazolines belong to heterocyclic chemistry, also known as 1,3-naphthalenes. The backbone consists of two six-membered aromatic rings fused to each other, with two nitrogen atoms at positions 1 and 3 on the backbone. The presence of these two nitrogen atoms in quinazoline increases its importance in pharmaceutical and biological reactions. Quinazolines and their derivatives are among the most important heterocyclic compounds due to their diverse chemical reactivity and important range of biological activities.