200px, Dacarbazine is a triazene used in the treatment of melanoma and Hodgkin's lymphoma">melanoma.html" ;"title="Dacarbazine is a triazene used in the treatment of melanoma">Dacarbazine is a triazene used in the treatment of melanoma and Hodgkin's lymphoma. Triazenes are organic compounds that contain the functional group R¹−N=N−NR²R³, where the R are each any of various types of substituent groups. Some medications and dyes are triazenes. Formally, the triazenes are related to the unstable chemical

triazene Triazene is an unsaturated inorganic compound having the chemical formula N3 H3. It has one double bond and is the second-simplest member of the azene class of hydronitrogen compounds, after diimide. Triazenes are a class of organic compound ...

, H₂N−N=NH.

Production

Triazenes are prepared from the ''N''-coupling reaction between

diazonium salt Diazonium compounds or diazonium salts are a group of organic compounds sharing a common functional group where R can be any organic group, such as an alkyl or an aryl, and X is an inorganic or organic anion, such as a halide. The parent, comp ...

s and primary or secondary

amine In chemistry, amines (, ) are organic compounds that contain carbon-nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of elec ...

s. The coupling reactions are typically mild, using a base such as

sodium acetate Sodium acetate, CH3COONa, also abbreviated Sodium, NaOxygen, OAcetyl, Ac, is the sodium Salt (chemistry), salt of acetic acid. This salt is colorless, deliquescent, and hygroscopy, hygroscopic. Applications Biotechnological Sodium acetate is u ...

sodium carbonate Sodium carbonate (also known as washing soda, soda ash, sal soda, and soda crystals) is the inorganic compound with the formula and its various hydrates. All forms are white, odourless, water-soluble salts that yield alkaline solutions in water ...

, or

sodium bicarbonate Sodium bicarbonate ( IUPAC name: sodium hydrogencarbonate), commonly known as baking soda or bicarbonate of soda (or simply “bicarb” especially in the UK) is a chemical compound with the formula NaHCO3. It is a salt composed of a sodium cat ...

. The diazonium reagents are themselves available starting from amines. For symmetrical triazenes derived from primary amines, partial diazotization gives a mixture of the original amine and its diazo derivative that then couple with each other. For example,

1,3-diphenyltriazene 1,3-Diphenyltriazene is the organic compound with the formula PhN=N-N(H)Ph (Ph = C6H5). It is a prototypical triazenes, triazene, i.e. a compound with the functional group RN=N-NR2. It is a pale yellow solid, prepared by the reaction of phenyldi ...

(PhN=N−NHPh) can be made from

aniline Aniline (From , meaning ' indigo shrub', and ''-ine'' indicating a derived substance) is an organic compound with the formula . Consisting of a phenyl group () attached to an amino group (), aniline is the simplest aromatic amine. It is an in ...

in a

one-pot reaction In chemistry a one-pot synthesis is a strategy to improve the efficiency of a chemical reaction in which a reactant is subjected to successive chemical reactions in just one reactor. This is much desired by chemists because avoiding a lengthy ...

. For asymmetrical triazenes, for example (phenyldiazenyl)pyrrolidine (PhN=N−NC₄H₈), the

phenyldiazonium Benzenediazonium tetrafluoroborate is an organic compound with the chemical formula, formula 6H5N2F4. It is a salt of a diazonium compound, diazonium cation and tetrafluoroborate. It exists as a colourless solid that is soluble in polar solve ...

salt must be pre-made. : Azo N coupling

Analogues of

Tröger's base Tröger's base is a white solid tetracyclic organic compound. Its chemical formula is . Tröger's base and its analogs are soluble in various organic solvents and strong acidic aqueous solutions due to their protonation. It is named after Julius ...

containing a symmetric pair of asymmetric triazene side-chains have been obtained similarly. : Bis-triazene

Reactions and applications

Triazenes derived from

primary amine In chemistry, amines (, ) are organic compounds that contain carbon-nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of elec ...

s engage in

tautomerism In chemistry, tautomers () are structural isomers (constitutional isomers) of chemical compounds that readily interconvert. The chemical reaction interconverting the two is called tautomerization. This conversion commonly results from the reloca ...

. In the case of symmetric triazenes, the tautomers are identical. : Triazenes can be converted to diazonium salts. Triazenes decompose in the presence of protonating or alkylating agents into quaternary amines and diazonium salts; as such triazenes have been used as an ''in situ'' source of

diazonium Diazonium compounds or diazonium salts are a group of organic compounds sharing a common functional group where R can be any organic group, such as an alkyl or an aryl, and X is an inorganic or organic anion, such as a halide. The parent, compou ...

that reacted with

sodium sulfide Sodium sulfide is a chemical compound with the formula Na2 S, or more commonly its hydrate Na2S·9 H2O. Both the anhydrous and the hydrated salts are colorless solids, although technical grades of sodium sulfide are generally yellow to brick red ...

to give the corresponding

thiophenol Thiophenol is an organosulfur compound with the formula C6H5SH, sometimes abbreviated as PhSH. This foul-smelling colorless liquid is the simplest aromatic thiol. The chemical structures of thiophenol and its derivatives are analogous to phen ...

s. A strategy for the protection and deprotection of sensitive

secondary amine In chemistry, amines (, ) are organic compounds that contain carbon-nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of elec ...

s is based on this principle. Polymeric triazenes are applied as conductive and absorbent materials. Triazenes have been used in the synthesis of

cinnoline Cinnoline is an aromatic heterocyclic compound with the formula C8H6N2. It is isomeric with other naphthyridines including quinoxaline, phthalazine and quinazoline. Properties The free base can be obtained as an oil by treatment of the hydr ...

, functionalized

lactam A lactam is a Cyclic compound, cyclic amide, formally derived from an amino alkanoic acid through cyclization reactions. The term is a portmanteau of the words ''lactone'' + ''amide''. Nomenclature Greek_alphabet#Letters, Greek prefixes in alpha ...

s, and

coumarin Coumarin () or 2''H''-chromen-2-one is an aromatic organic chemical compound with formula . Its molecule can be described as a benzene molecule with two adjacent hydrogen atoms replaced by an unsaturated lactone ring , forming a second six-me ...

References

{{Authority control Functional groups *