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.
Indazoles are a class of organic heterocyclic compounds, also known as 1,2-diazaindene and benzopyrazole. Indazole is a good bioisomer of phenol, which is more lipophilic than phenol and less prone to phase I and II metabolism. Indazole derivatives have a wide range of biological activities, and it has been confirmed that indazole compounds have anti-tumor, analgesic, anti-inflammatory and other drug activities. Anticancer is the most important application field of indazole drugs. Renal cell carcinoma, solid tumor, nausea and vomiting caused by chemotherapy and leukemia are the main indications of this structural backbone drug.