Names | |||
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Preferred IUPAC name Quinazoline [1] | |||
Other names 1,3-diazanaphthalene benzopyrimidine phenmiazine benzo-1,3-diazine | |||
Identifiers | |||
3D model (JSmol) | |||
ChEBI | |||
ChEMBL | |||
ChemSpider | |||
ECHA InfoCard | 100.005.424 | ||
EC Number |
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PubChem CID | |||
UNII | |||
CompTox Dashboard (EPA) | |||
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Properties | |||
C8H6N2 | |||
Molar mass | 130.150 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) | ||
Soluble | |||
Acidity (pKa) | 3.51 [2] | ||
Structure | |||
2.2 D [3] | |||
Hazards | |||
Occupational safety and health (OHS/OSH): | |||
Main hazards | Irritant | ||
GHS labelling: | |||
Warning | |||
H315, H319, H335 | |||
P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501 | |||
Flash point | 106 °C (223 °F; 379 K) | ||
Safety data sheet (SDS) | External MSDS | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Quinazoline is an 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. Over 200 biologically active quinazoline and quinoline alkaloids are identified. [4] [5]
The synthesis of quinazoline was first reported in 1895 by August Bischler and Lang through the decarboxylation of the 2-carboxy derivative (quinazoline-2-carboxylic acid). [6] 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. [7]
Methods have been reviewed. [8] An efficient route to the parent heterocycle proceeds via the 4-chloro derivative to the tosylhydrazide, which is removed by base. [9]
Quinazoline protonates (and methylates) at N3. Protonation induces hydration. Many mildly acidic substrates add across the C=N3 bond, these include hydrogen cyanide, sodium bisulfite, and methyl ketones. [10]
In warm solution, quinazoline hydrolyzes under acidic and alkaline conditions to 2-aminobenzaldehyde (or the products of its self-condensation) and formic acid and ammonia/ammonium. [3]
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. [3]
In May 2003, the U.S. Food and Drug Administration (FDA) approved the quinazoline 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. [11] [12] [13]
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). [14] [15] [16] [17]
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. [18] [19]
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. [20]
A tyrosine kinase is an enzyme that can transfer a phosphate group from ATP to the tyrosine residues of specific proteins inside a cell. It functions as an "on" or "off" switch in many cellular functions.
Autocrine signaling is a form of cell signaling in which a cell secretes a hormone or chemical messenger that binds to autocrine receptors on that same cell, leading to changes in the cell. This can be contrasted with paracrine signaling, intracrine signaling, or classical endocrine signaling.
Gefitinib, sold under the brand name Iressa, is a medication used for certain breast, lung and other cancers. Gefitinib is an EGFR inhibitor, like erlotinib, which interrupts signaling through the epidermal growth factor receptor (EGFR) in target cells. Therefore, it is only effective in cancers with mutated and overactive EGFR, but resistances to gefitinib can arise through other mutations. It is marketed by AstraZeneca and Teva.
The epidermal growth factor receptor is a transmembrane protein that is a receptor for members of the epidermal growth factor family of extracellular protein ligands.
Erlotinib, sold under the brand name Tarceva among others, is a medication used to treat non-small cell lung cancer (NSCLC) and pancreatic cancer. Specifically it is used for NSCLC with mutations in the epidermal growth factor receptor (EGFR) — either an exon 19 deletion (del19) or exon 21 (L858R) substitution mutation — which has spread to other parts of the body. It is taken by mouth.
Receptor tyrosine-protein kinase erbB-2 is a protein that normally resides in the membranes of cells and is encoded by the ERBB2 gene. ERBB is abbreviated from erythroblastic oncogene B, a gene originally isolated from the avian genome. The human protein is also frequently referred to as HER2 or CD340.
Targeted therapy or molecularly targeted therapy is one of the major modalities of medical treatment (pharmacotherapy) for cancer, others being hormonal therapy and cytotoxic chemotherapy. As a form of molecular medicine, targeted therapy blocks the growth of cancer cells by interfering with specific targeted molecules needed for carcinogenesis and tumor growth, rather than by simply interfering with all rapidly dividing cells. Because most agents for targeted therapy are biopharmaceuticals, the term biologic therapy is sometimes synonymous with targeted therapy when used in the context of cancer therapy. However, the modalities can be combined; antibody-drug conjugates combine biologic and cytotoxic mechanisms into one targeted therapy.
Lapatinib (INN), used in the form of lapatinib ditosylate (USAN) is an orally active drug for breast cancer and other solid tumours. It is a dual tyrosine kinase inhibitor which interrupts the HER2/neu and epidermal growth factor receptor (EGFR) pathways. It is used in combination therapy for HER2-positive breast cancer. It is used for the treatment of patients with advanced or metastatic breast cancer whose tumors overexpress HER2 (ErbB2).
The ErbB family of proteins contains four receptor tyrosine kinases, structurally related to the epidermal growth factor receptor (EGFR), its first discovered member. In humans, the family includes Her1, Her2 (ErbB2), Her3 (ErbB3), and Her4 (ErbB4). The gene symbol, ErbB, is derived from the name of a viral oncogene to which these receptors are homologous: erythroblastic leukemia viral oncogene. Insufficient ErbB signaling in humans is associated with the development of neurodegenerative diseases, such as multiple sclerosis and Alzheimer's disease, while excessive ErbB signaling is associated with the development of a wide variety of types of solid tumor.
Receptor tyrosine-protein kinase erbB-3, also known as HER3, is a membrane bound protein that in humans is encoded by the ERBB3 gene.
Afatinib, sold under the brand name Gilotrif among others, is a medication which is used to treat non-small cell lung carcinoma (NSCLC). It belongs to the tyrosine kinase inhibitor family of medications. It is taken by mouth.
Neratinib (INN), sold under the brand name Nerlynx, is a tyrosine kinase inhibitor anti-cancer medication used for the treatment of breast cancer.
Targeted therapy of lung cancer refers to using agents specifically designed to selectively target molecular pathways responsible for, or that substantially drive, the malignant phenotype of lung cancer cells, and as a consequence of this (relative) selectivity, cause fewer toxic effects on normal cells.
A tyrosine kinase inhibitor (TKI) is a pharmaceutical drug that inhibits tyrosine kinases. Tyrosine kinases are enzymes responsible for the activation of many proteins by signal transduction cascades. The proteins are activated by adding a phosphate group to the protein (phosphorylation), a step that TKIs inhibit. TKIs are typically used as anticancer drugs. For example, they have substantially improved outcomes in chronic myelogenous leukemia. They have also been used to treat other diseases, such as idiopathic pulmonary fibrosis.
ALK inhibitors are anti-cancer drugs that act on tumours with variations of anaplastic lymphoma kinase (ALK) such as an EML4-ALK translocation. They fall under the category of tyrosine kinase inhibitors, which work by inhibiting proteins involved in the abnormal growth of tumour cells. All the current approved ALK inhibitors function by binding to the ATP pocket of the abnormal ALK protein, blocking its access to energy and deactivating it. A majority of ALK-rearranged NSCLC harbour the EML4-ALK fusion, although as of 2020, over 92 fusion partners have been discovered in ALK+ NSCLC. For each fusion partner, there can be several fusion variants depending on the position the two genes were fused at, and this may have implications on the response of the tumour and prognosis of the patient.
Angiokinase inhibitors are a new therapeutic target for the management of cancer. They inhibit tumour angiogenesis, one of the key processes leading to invasion and metastasis of solid tumours, by targeting receptor tyrosine kinases. Examples include nintedanib, afatinib and motesanib.
Growth factor receptor inhibitors are drugs that target the growth factor receptors of cells. They interfere with binding of the growth factor to the corresponding growth factor receptors, impeding cell growth and are used medically to treat cancer.
Osimertinib, sold under the brand name Tagrisso, is a medication used to treat non-small-cell lung carcinomas with specific mutations. It is a third-generation epidermal growth factor receptor tyrosine kinase inhibitor.
Tesevatinib is an experimental drug proposed for use in kidney cancer and polycystic kidney disease. The drug was first developed by Exelixis, Inc. and was later acquired by Kadmon Corporation. Tesevatinib binds to and inhibits several tyrosine receptor kinases that play major roles in tumor cell proliferation and tumor vascularization, including epidermal growth factor receptor, epidermal growth factor receptor 2, vascular endothelial growth factor receptor (VEGFR), and ephrin B4 (EphB4).
VEGFR-2 inhibitor, also known as kinase insert domain receptor(KDR) inhibitor, are tyrosine kinase receptor inhibitors that reduce angiogenesis or lymphangiogenesis, leading to anticancer activity. Generally they are small, synthesised molecules that bind competitively to the ATP-site of the tyrosine kinase domain. VEGFR-2 selective inhibitor can interrupt multiple signaling pathways involved in tumor, including proliferation, metastasis and angiogenesis.