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Quinazoline numbering.png
Quinazoline molecule
Quinazoline molecule
IUPAC name
Other names



253-82-7 YesY
ChEBI CHEBI:36621 YesY
ChEMBL ChEMBL301359 YesY
ChemSpider 8855 YesY
ECHA InfoCard 100.005.424
EC Number 205-965-3
Jmol 3D model Interactive image
PubChem 9210
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)
Acidity (pKa) 3.51[1]
2.2 D[2]
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).
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Infobox references

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.

Synthesis and reactions[edit]

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).[3] 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.[4]


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

Electrophilic and nucleophilic substitution[edit]

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.[2]

Biological and pharmacological significance[edit]


In May 2003, the U.S. Food and Drug Administration (FDA) approved a quinazoline-containing drug gefitinib. The drug, produced by AstraZeneca, is an inhibitor of the protein kinase of epidermal growth factor receptor (EGFR). It binds to the ATP-binding site of EGFR, thus inactivating the anti-apoptotic Ras signal transduction cascade preventing further growth of cancer cells.[5][6][7]


In March 2007, GlaxoSmithKline's drug lapatinib was approved by the U.S. FDA to treat advanced-stage or metastatic breast cancer in combination with Roche's capecitabine. Lapatinib eliminates the growth of breast cancer stem cells that cause tumor growth. The binding of lapatinib to the ATP-binding site in the EGFR and human epidermal growth factor receptor 2 (HER2) protein kinase domains inhibits signal mechanism activation (through reversible, competitive inhibition).[8][9][10][11]


In May 2013, erlotinib, a drug manufactured by Astellas, was approved by the U.S. FDA to treat NSCLC patients with tumors caused by mutations of EGFR. The binding of erlotinib to the ATP-binding sites of the EGFR receptors prevents EGFR from producing phosphotyrosine residues (due to competitive inhibition), thus rendering the receptor incapable of generating signal cascades to promote cell growth.[12][13]


In July 2013, the U.S. FDA approved afatinib, a drug developed by Boehringer Ingelheim, as an irreversible, competitive inhibitor of HER2 and EGFR kinases. While afatinib demonstrates a similar mechanism to laptinib in which it acts as an irreversible HER2 and EGFR inhibitor, afatinib has also shown activity against tyrosine kinases that have become resistant to gefinitib and erlotinib.[14]

See also[edit]


  1. ^ Armarego, W. L. F. (1963). "Quinazolines". Advances in Heterocyclic Chemistry. 1: 253–309. doi:10.1016/S0065-2725(08)60527-9. ISBN 9780120206018. 
  2. ^ a b c Büchel, K. H., ed. Methods of Organic Chemistry (Houben-Weyl): Additional and Supplementary Volumes to the 4th Edition. New York: Georg Thieme Verlag Stuttgart, 2001.
  3. ^ Asif, M. Chemical Characteristics, Synthetic Methods, and Biological Potential of Quinazoline and Quinazolinone Derivatives, International Journal of Medicinal Chemistry, Article ID 395637, 2014. doi:10.1155/2014/395637
  4. ^ Morgan, G.T., ed. Abstract of Papers. Journal of the Chemical Society. London: Gurney & Jackson, 1904. Print.
  5. ^ "Iressa(Gefitinib)" (PDF). US Food and Drug Administration. 2 May 2003. 
  6. ^ Lynch, Thomas J.; Bell, Daphne W.; Sordella, Raffaella; Gurubhagavatula, Sarada; Okimoto, Ross A.; Brannigan, Brain W.; Harris, Patricia L.; Haserlat, Sara M.; Supko, Jeffrey G.; Haluska, Frank G.; Louis, David N.; Christiani, David C.; Settleman, Jeff; Haber, Daniel A (May 20, 2004). "Activating Mutations in the Epidermal Growth Factor Receptor Underlying Responsiveness of Non-Small-Cell Lung Cancer to Gefitinib". NEJM. 350 (21): 2129–39. doi:10.1056/nejmoa040938. 
  7. ^ Takimoto CH, Calvo E. "Principles of Oncologic Pharmacotherapy" in Pazdur R, Wagman LD, Camphausen KA, Hoskins WJ (Eds) Cancer Management: A Multidisciplinary Approach. 11 ed. 2008.
  8. ^ "Lapatinib". US Food and Drug Administration. 13 March 2007. 
  9. ^ Wood ER, Truesdale AT, McDonald OB, Yuan D, Hassell A, Dickerson SH, Ellis B, Pennisi C, et al. (2004). "A unique structure for epidermal growth factor receptor bound to GW572016 (Lapatinib): relationships among protein conformation, inhibitor off-rate, and receptor activity in tumor cells". Cancer Research. 64 (18): 6652–9. doi:10.1158/0008-5472.CAN-04-1168. PMID 15374980. 
  10. ^ Rodriguez,A. (April 2008). New type of drug shrinks primary breast cancer tumors significantly in just six weeks; research provides leads to a new target in cancer treatment – the cancer stem cell. 
  11. ^ Nelson MH, Dolder CR (February 2006). "Lapatinib: a novel dual tyrosine kinase inhibitor with activity in solid tumors". Ann Pharmacother. 40 (2): 261–9. doi:10.1345/aph.1G387. PMID 16418322. 
  12. ^ "Erlotinib". US Food and Drug Administration. 14 May 2013. 
  13. ^ Raymond E, Faivre S, Armand J (2000). "Epidermal growth factor receptor tyrosine kinase as a target for anticancer therapy". Drugs. 60 Suppl 1: 15–23; discussion 41–2. doi:10.2165/00003495-200060001-00002. PMID 11129168. 
  14. ^ "Afatinib". US Food and Drug Administration. 12 July 2013.