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.
Thiadiazoles are a subfamily of azoles. Structurally, they are five-membered heterocyclic compounds containing two nitrogen atoms and one sulfur atom, and two double bonds, forming an aromatic ring. Depending on the relative positions of the heteroatoms, there are four possible structures; these forms do not interconvert and are therefore structural isomers rather than tautomers. These compounds themselves are rarely synthesized and have no particular utility, however, compounds that use them as structural motifs are fairly common in pharmacology.