What Is Quinazoline?
Quinazoline is an organic compound with the molecular formula C8H6N2, known for its role in organic synthesis and pharmaceutical applications. It is a colorless to pale yellow crystalline powder with a characteristic odor, soluble in ethanol and acetone but insoluble in water.
The CAS number of quinazoline is 253-82-7. It has a molecular weight of 130.15, a melting point of 120-122°F (49-50°C), a boiling point of 469.4°F (243°C), and a density of 1.351 g/cm3. Its flash point is 222.8°F (106°C), and it has an acid dissociation constant (pKa) of 3.51.
Uses of Quinazoline
Quinazoline and its derivatives are primarily used in organic synthesis. In medicine, these compounds serve as anti-malarial agents, and treatments for brain tumors, and other cancers. Quinazoline rings are also integral to antihypertensive drugs like doxazosin. Additionally, quinazoline compounds find applications in electronics, particularly in organic light-emitting diode (OLED) materials for displays.
Properties of Quinazoline
Quinazoline is prone to various addition reactions, particularly at the N3 position, and undergoes hydrolysis in acidic or alkaline solutions. The decomposition products include 2-aminobenzaldehyde, formic acid, and ammonia. Its benzene ring is more reactive to electrophilic substitution reactions compared to the pyrimidine ring.
Types of Quinazoline
Available mainly for research and development purposes, quinazoline is sold in small quantities like 1 g or 5 g, and is considered a relatively expensive reagent. It is commonly handled at room temperature. Derivatives of quinazoline available commercially include 4-chloroquinazoline and quinazoline-2-carboxylic acid hydrochloride, among others.
Other Information on Quinazoline
1. Synthesis of Quinazoline
Quinazoline can be synthesized through various methods, including the Niementowski quinazoline synthesis, which involves the reaction of anthranilic acid with amino acids. Another efficient method includes the introduction and removal of a tosylhydrazide group to 4-chloroquinazoline.
2. Derivatives of Quinazolines
Derivatives of quinazoline, such as tyrosine kinase inhibitors, are used in molecular targeted therapies. Examples include gefitinib, erlotinib, afatinib, and lapatinib, which are used for treating various cancers.