1,2,4-Triazole

Last updated
1,2,4-Triazole
Structural formula of 1,2,4-Triazole.svg
1,2,4-Triazole3d.png
Names
Preferred IUPAC name
1H-1,2,4-Triazole
Other names
1,2,4-Triazole pyrrodiazole
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.005.476 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/C2H3N3/c1-3-2-5-4-1/h1-2H,(H,3,4,5) Yes check.svgY
    Key: NSPMIYGKQJPBQR-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C2H3N3/c1-3-2-5-4-1/h1-2H,(H,3,4,5)
    Key: NSPMIYGKQJPBQR-UHFFFAOYAZ
  • N1C=NC=N1
Properties
C2H3N3
Molar mass 69.00725
Appearancewhite solid
Density 1.439 g/cm3
Melting point 120 to 121 °C (248 to 250 °F; 393 to 394 K)
Boiling point 260 °C (500 °F; 533 K)
very soluble
Acidity (pKa)10,3
Basicity (pKb)11,8
Hazards
Flash point 140 °C (284 °F; 413 K)
Related compounds
Related compounds
1,2,3-triazole imidazole
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

1,2,4-Triazole (as ligand in coordination compounds, Htrz abbreviation is sometimes used) is one of a pair of isomeric chemical compounds with molecular formula C2H3N3, called triazoles, which have a five-membered ring of two carbon atoms and three nitrogen atoms. 1,2,4-Triazole and its derivatives find use in a wide variety of applications. [1]

Contents

Structure and properties

1,2,4-Triazole is a planar molecule. The C-N and N-N distances fall into a narrow range 136 - 132 picometers, consistent with the aromaticity. [2] Although two tautomers can be envisioned, only one exists practically speaking.

1,2,4-Triazole is amphoteric, being susceptible to both N-protonation and deprotonation in aqueous solution. The pKa of 1,2,4-triazolium (C2N3H4+) is 2.45. The pKa of the neutral molecule is 10.26. [3]

Synthesis and occurrence

Portion of the structure of {[Fe(triazolate)(triazole)2](BF4)}n. Fe(triazolate)3 (FIBCEA01).png
Portion of the structure of {[Fe(triazolate)(triazole)2](BF4)}n.

1,2,4-Triazoles can be prepared using the Einhorn–Brunner reaction or the Pellizzari reaction. Unsubstituted 1,2,4-triazole can be prepared from thiosemicarbazide by acylation with formic acid followed by cyclization of 1-formyl-3-thiosemicarbazide into 1,2,4-triazole-3(5)-thiol; oxidation of the thiol by nitric acid or hydrogen peroxide yields 1,2,4-triazole. [5]

1,2,4-Triazoles are featured in many kinds of drugs. [6] [7] Notable triazoles include the antifungal drugs fluconazole and itraconazole [8] and the plant growth regulator paclobutrazol. [9] Triazolate is a common bridging ligand in coordination chemistry. [10]

Related Research Articles

<span class="mw-page-title-main">Drug discovery</span> Pharmaceutical procedure

In the fields of medicine, biotechnology and pharmacology, drug discovery is the process by which new candidate medications are discovered.

<span class="mw-page-title-main">Drug design</span> Invention of new medications based on knowledge of a biological target

Drug design, often referred to as rational drug design or simply rational design, is the inventive process of finding new medications based on the knowledge of a biological target. The drug is most commonly an organic small molecule that activates or inhibits the function of a biomolecule such as a protein, which in turn results in a therapeutic benefit to the patient. In the most basic sense, drug design involves the design of molecules that are complementary in shape and charge to the biomolecular target with which they interact and therefore will bind to it. Drug design frequently but not necessarily relies on computer modeling techniques. This type of modeling is sometimes referred to as computer-aided drug design. Finally, drug design that relies on the knowledge of the three-dimensional structure of the biomolecular target is known as structure-based drug design. In addition to small molecules, biopharmaceuticals including peptides and especially therapeutic antibodies are an increasingly important class of drugs and computational methods for improving the affinity, selectivity, and stability of these protein-based therapeutics have also been developed.

<span class="mw-page-title-main">Triazine</span> Aromatic, heterocyclic compound

Triazines are a class of nitrogen-containing heterocycles. The parent molecules' molecular formula is C3H3N3. They exist in three isomeric forms, 1,3,5-triazines being common.

Azoles are a class of five-membered heterocyclic compounds containing a nitrogen atom and at least one other non-carbon atom as part of the ring. Their names originate from the Hantzsch–Widman nomenclature. The parent compounds are aromatic and have two double bonds; there are successively reduced analogs with fewer. One, and only one, lone pair of electrons from each heteroatom in the ring is part of the aromatic bonding in an azole. Names of azoles maintain the prefix upon reduction. The numbering of ring atoms in azoles starts with the heteroatom that is not part of a double bond, and then proceeds towards the other heteroatom.

<span class="mw-page-title-main">Terconazole</span> Chemical compound

Terconazole is an antifungal drug used to treat vaginal yeast infection. It comes as a lotion or a suppository and disrupts the biosynthesis of fats in a yeast cell. It has a relatively broad spectrum compared to azole compounds but not triazole compounds. Testing shows that it is a suitable compound for prophylaxis for those that suffer from chronic vulvovaginal candidiasis.

<span class="mw-page-title-main">Einhorn–Brunner reaction</span>

The Einhorn–Brunner reaction is the designation for the chemical reaction of imides with alkyl hydrazines to form an isomeric mixture of 1,2,4-triazoles. It was initially described by the German chemist Alfred Einhorn in a paper, published in 1905, describing N-methylol compounds of amides. In 1914 chemist Karl Brunner published a paper expanding on Einhorn's research of the reaction pictured below, thus resulting in the naming as the Einhorn-Brunner. Substituted 1,2,4-triazole have been prepared from diverse imides and hydrazines.

A triazole is a heterocyclic compound featuring a five-membered ring of two carbon atoms and three nitrogen atoms with molecular formula C2H3N3. Triazoles exhibit substantial isomerism, depending on the positioning of the nitrogen atoms within the ring.

<span class="mw-page-title-main">Taribavirin</span> Antiviral drug

Taribavirin is an antiviral drug in Phase III human trials, but not yet approved for pharmaceutical use. It is a prodrug of ribavirin, active against a number of DNA and RNA viruses. Taribavirin has better liver-targeting than ribavirin, and has a shorter life in the body due to less penetration and storage in red blood cells. It is expected eventually to be the drug of choice for viral hepatitis syndromes in which ribavirin is active. These include hepatitis C and perhaps also hepatitis B and yellow fever.

<span class="mw-page-title-main">2-Imidazoline</span> Chemical compound

2-Imidazoline (Preferred IUPAC name: 4,5-dihydro-1H-imidazole) is one of three isomers of the nitrogen-containing heterocycle imidazoline, with the formula C3H6N2. The 2-imidazolines are the most common imidazolines commercially, as the ring exists in some natural products and some pharmaceuticals. They also have been examined in the context of organic synthesis, coordination chemistry, and homogeneous catalysis.

In medicinal chemistry, bioisosteres are chemical substituents or groups with similar physical or chemical properties which produce broadly similar biological properties in the same chemical compound. In drug design, the purpose of exchanging one bioisostere for another is to enhance the desired biological or physical properties of a compound without making significant changes in chemical structure. The main use of this term and its techniques are related to pharmaceutical sciences. Bioisosterism is used to reduce toxicity, change bioavailability, or modify the activity of the lead compound, and may alter the metabolism of the lead.

Pyrazolone is 5-membered heterocycle containing two adjacent nitrogen atoms. It can be viewed as a derivative of pyrazole possessing an additional carbonyl (C=O) group. Compounds containing this functional group are useful commercially in analgesics and dyes.

<span class="mw-page-title-main">(+)-CPCA</span> Stimulant drug

(+)-CPCA is a stimulant drug similar in structure to pethidine and to RTI-31, but nocaine is lacking the two-carbon bridge of RTI-31's tropane skeleton. This compound was first developed as a substitute agent for cocaine.

<span class="mw-page-title-main">8-Hydroxyquinoline</span> Chemical compound

8-Hydroxyquinoline is an organic compound derived from the heterocycle quinoline. A colorless solid, its conjugate base is a chelating agent, which is used for the quantitative determination of metal ions.

Molecular binding is an attractive interaction between two molecules that results in a stable association in which the molecules are in close proximity to each other. It is formed when atoms or molecules bind together by sharing of electrons. It often, but not always, involves some chemical bonding.

The Pellizzari reaction was discovered in 1911 by Guido Pellizzari, and is the organic reaction of an amide and a hydrazide to form a 1,2,4-triazole.

<span class="mw-page-title-main">Thiosemicarbazide</span> Chemical compound

Thiosemicarbazide is the chemical compound with the formula H2NC(S)NHNH2. A white, odorless solid, it is related to thiourea (H2NC(S)NH2) by the insertion of an NH center. They are commonly used as ligands for transition metals. Many thiosemicarbazides are known. These feature an organic substituent in place of one or more H's of the parent molecule. 4-Methyl-3-thiosemicarbazide is a simple example.

<span class="mw-page-title-main">Rhodocene</span> Organometallic chemical compound

Rhodocene is a chemical compound with the formula [Rh(C5H5)2]. Each molecule contains an atom of rhodium bound between two planar aromatic systems of five carbon atoms known as cyclopentadienyl rings in a sandwich arrangement. It is an organometallic compound as it has (haptic) covalent rhodium–carbon bonds. The [Rh(C5H5)2] radical is found above 150 °C (302 °F) or when trapped by cooling to liquid nitrogen temperatures (−196 °C [−321 °F]). At room temperature, pairs of these radicals join via their cyclopentadienyl rings to form a dimer, a yellow solid.

<span class="mw-page-title-main">Half sandwich compound</span> Class of coordination compounds

Half sandwich compounds, also known as piano stool complexes, are organometallic complexes that feature a cyclic polyhapto ligand bound to an MLn center, where L is a unidentate ligand. Thousands of such complexes are known. Well-known examples include cyclobutadieneiron tricarbonyl and (C5H5)TiCl3. Commercially useful examples include (C5H5)Co(CO)2, which is used in the synthesis of substituted pyridines, and methylcyclopentadienyl manganese tricarbonyl, an antiknock agent in petrol.

<span class="mw-page-title-main">Imidazothiazoles</span> Class of chemical compounds comprising a bicyclic heterocycle

Imidazothiazoles are a class of chemical compounds containing a bicyclic heterocycle consisting of an imidazole ring fused to a thiazole ring. The structure contains three non-carbon or heteroatoms: two nitrogen atoms and one sulfur atom. Imidazothiazole derivatives show a broad spectrum of in vitro, i.e. "in the petri dish", activity such as anticancer, antipsychotic, antimicrobial, antifungal, and anthelmintic.

<span class="mw-page-title-main">1,2-Dioxolane</span> Chemical compound

1,2-Dioxolane is a chemical compound with formula C3H6O2, consisting of a ring of three carbon atoms and two oxygen atoms in adjacent positions. Its condensed structural formula is [–(CH
2
)3–O–O–]
.

References

  1. Potts K. T. (1961). "The Chemistry of 1,2,4-Triazoles". Chemical Reviews . 61 (2): 87–127. doi:10.1021/cr60210a001.
  2. Jeffrey, G. A.; Ruble, J. R.; Yates, J. H. (1983). "Neutron diffraction at 15 and 120 K and ab initio molecular-orbital studies of the molecular structure of 1,2,4-triazole". Acta Crystallographica Section B: Structural Science. 39 (3): 388–394. Bibcode:1983AcCrB..39..388J. doi:10.1107/S010876818300258X.
  3. Garratt, Peter J. (1996). "1,2,4-Triazoles". Comprehensive Heterocyclic Chemistry II. pp. 127–163. doi:10.1016/B978-008096518-5.00080-0. ISBN   978-0-08-096518-5.
  4. Grosjean, Arnaud; Négrier, Philippe; Bordet, Pierre; Etrillard, Céline; Mondieig, Denise; Pechev, Stanislav; Lebraud, Eric; Létard, Jean-François; Guionneau, Philippe (2013). "Crystal Structures and Spin Crossover in the Polymeric Material [Fe(HTRZ)2(TRZ)](BF4) Including Coherent-Domain Size Reduction Effects" (PDF). European Journal of Inorganic Chemistry. 2013 (5–6): 796–802. doi:10.1002/ejic.201201121.
  5. C. Ainsworth (1960). "1,2,4-Triazole". Organic Syntheses. 40: 99. doi:10.15227/orgsyn.040.0099.
  6. Keri, Rangappa S.; Patil, Siddappa A.; Budagumpi, Srinivasa; Nagaraja, Bhari Mallanna (2015). "Triazole: A Promising Antitubercular Agent". Chemical Biology & Drug Design. 86 (4): 410–423. doi:10.1111/cbdd.12527. PMID   25643871. S2CID   9313180.
  7. Kaur, Ramandeep; Ranjan Dwivedi, Ashish; Kumar, Bhupinder; Kumar, Vinod (2016). "Recent Developments on 1,2,4-Triazole Nucleus in Anticancer Compounds: A Review". Anti-Cancer Agents in Medicinal Chemistry. 16 (4): 465–489. doi:10.2174/1871520615666150819121106. PMID   26286663.
  8. Kathiravan, Muthu K.; Salake, Amol B.; Chothe, Aparna S.; Dudhe, Prashik B.; Watode, Rahul P.; Mukta, Maheshwar S.; Gadhwe, Sandeep (2012). "The biology and chemistry of antifungal agents: A review". Bioorganic & Medicinal Chemistry. 20 (19): 5678–5698. doi:10.1016/j.bmc.2012.04.045. PMID   22902032.
  9. Tesfahun, Wakjira (January 1, 2018). Yildiz, Fatih (ed.). "A review on: Response of crops to paclobutrazol application". Cogent Food & Agriculture. 4 (1): 1–9. Bibcode:2018CogFA...425169T. doi: 10.1080/23311932.2018.1525169 . S2CID   134517280.
  10. Haasnoot, Jaap G. (2000). "Mononuclear, oligonuclear and polynuclear metal coordination compounds with 1,2,4-triazole derivatives as ligands". Coordination Chemistry Reviews. 200–202: 131–185. doi:10.1016/S0010-8545(00)00266-6.