喹唑啉（Quinazoline）是一种杂环化合物，化学式C₈H₆N₂，由一个苯环与一个嘧啶环稠合而成。喹唑啉也可看做萘环的两个CH被N原子替换，这样的结构称为萘啶。

喹唑啉及其衍生物的典型制备方法是在氨或胺存在下加热2-酰基-N-酰苯胺。

邻氨基苯甲酸与酰胺反应合成4-氧代-3,4-二氢喹唑啉类，称为涅门托夫斯基喹唑啉合成。

Quinazoline is a organic compound with the formula C₈H₆N₂. It is an aromatic heterocycle with a bicyclic structure consisting of a two fused six-membered aromatic rings, a benzene ring and a pyrimidine ring. It is a light yellow crystalline solid that is soluble in water. Also known as 1,3-diazanaphthalene, quinazoline received its name from being an aza derivative of quinoline. Though the parent quinazoline molecule is rarely mentioned by itself in technical literature, substituted derivatives have been synthesized for medicinal purposes such as antimalarial and anticancer agents. Quinazoline is a planar molecule. It is isomeric with the other diazanaphthalenes of the benzodiazine subgroup: cinnoline, quinoxaline, and phthalazine.