Quinazoline

Quinazoline

Names
IUPAC name Quinazoline
Other names 1,3-diazanaphthalene benzopyrimidine phenmiazine benzo-1,3-diazine
Identifiers
CAS Number	253-82-7 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:36621 Y
ChEMBL	ChEMBL301359 Y
ChemSpider	8855 Y
ECHA InfoCard	100.005.424
EC Number	205-965-3
PubChem	9210
InChI InChI=1S/C8H6N2/c1-2-4-8-7(3-1)5-9-6-10-8/h1-6H Y Key: JWVCLYRUEFBMGU-UHFFFAOYSA-N Y InChI=1/C8H6N2/c1-2-4-8-7(3-1)5-9-6-10-8/h1-6H Key: JWVCLYRUEFBMGU-UHFFFAOYAV
SMILES c1ccc2c(c1)cncn2
Properties
Chemical formula	C8H6N2
Molar mass	130.15 g·mol−1
Appearance	light yellow crystals
Density	1.351 g/cm3, solid
Melting point	48°C (118°F; 321 K)
Boiling point	243°C (469°F; 516 K)
Solubility in water	Soluble
Acidity (pKa)	3.51
Structure
Dipole moment	2.2 D
Hazards
Main hazards	Irritant
Safety data sheet	External MSDS
S-phrases	S24 S25
Flash point	106 °C (223 °F; 379 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

benzopyrimidine

phenmiazine

Quinazoline is a organic compound with the formula C₈H₆N₂. It is an aromatic heterocycle with a bicyclic structure consisting of 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.

The first known synthesis of quinazoline was reported in 1895 by August Bischler and Lang through the decarboxylation of the 2-carboxy derivative (quinazoline-2-carboxylic acid). In 1903, Siegmund Gabriel reported the synthesis of the parent quinazoline from o-nitrobenzylamine, which was reduced with hydrogen iodide and red phosphorus to 2-aminobenzylamine. The reduced intermediate condenses with formic acid to yield dihydroquinazoline, which was oxidized to quinazoline.

Quinazoline hydrolyzes under acidic and alkaline conditions to 2-aminobenzaldehyde and formic acid and ammonia/ammonium.

The pyrimidine ring resists electrophilic substitution, although the 4-position is more reactive than the 2-position. In comparison, the benzene ring is more susceptible to electrophilic substitution. The ring position order of reactivity is 8 > 6 > 5 > 7. 2- and 4-halo derivatives of quinazoline undergo displacement by nucleophiles, such as piperidine.