Furazan: Difference between revisions

| Watchedfields = changed

| verifiedrevid = 400097852

| ImageFile = furazan numbering.png

| ImageSize = 120px

| ImageAlt = Skeletal formula of furazan with numbering convention for substituent groups

| ImageFileL1 = Furazan-3D-balls.png

| ImageAltL1 = Skeletal formula of furazan

| ImageFileR1 = Furazan-3D-spacefill.png

| ImageAltR1 = Space-filling model of the furazan molecule

| PIN = 1,2,5-Oxadiazole

| OtherNames =

|Section1 = {{Chembox Identifiers

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 60840

| InChI = 1/C2H2N2O/c1-2-4-5-3-1/h1-2H

| InChIKey = JKFAIQOWCVVSKC-UHFFFAOYAZ

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/C2H2N2O/c1-2-4-5-3-1/h1-2H

| StdInChIKey = JKFAIQOWCVVSKC-UHFFFAOYSA-N

| CASNo_Ref = {{cascite|correct|??}}

| CASNo = 288-37-9

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = 63LL54U9WN

| PubChem = 67517

| SMILES = n1oncc1

|Section2={{Chembox Properties

| Formula = C₂H₂N₂O

| MolarMass = 70.05008 g/mol

| Appearance = clear oil

| Density = 1.168 g/cm³<ref name="OlofsonMichelman1965" />

| MeltingPtC = -28

| MeltingPt_ref =<ref name="OlofsonMichelman1965" />

| BoilingPtC = 98

| BoilingPt_ref =<ref name="OlofsonMichelman1965" />

| Solubility =

|Section3={{Chembox Hazards

| MainHazards=

| FlashPt=

| AutoignitionPt =

'''Furazan''', or 1,2,5-oxadiazole, is a [[heterocyclic compound|heterocyclic]] [[aromaticity|aromatic]] [[organic compound]] consisting of a five-atom ring containing 1 oxygen and 2 nitrogen atoms. The furazan ring system is also found in the steroid [[furazabol]]. Furazan and its derivatives are obtained from the [[oxime]] derivatives of 1,2-[[diketone]]s.

==Synthesis==

In theory the simplest means of producing furazan is the cyclic-dehydration of glyoxime (the di-[[oxime]] of [[glyoxal]]), however the instability of furazan to high temperature or extremes of pH requires that this process be performed carefully. The formation of furazan from glyoxime is also exothermic and takes place with the copious evolution of noxious gases. The reaction may be achieved by heating glyoxime to 150&nbsp;°C in the presence of [[succinic anhydride]]. Furazan will evaporate at that temperature, which continuously removes the product from the reaction mixture.<ref name="OlofsonMichelman1965">{{cite journal|last1=Olofson|first1=R. A.|last2=Michelman|first2=J. S.|title=Furazan|journal=The Journal of Organic Chemistry|volume=30|issue=6|year=1965|pages=1854–1859|issn=0022-3263|doi=10.1021/jo01017a034}}</ref>

;3,4-Dimethylfurazan

3,4-Dimethylfurazan ([[boiling point|b.p.]] 154–159&nbsp;°C) is prepared by an analogous process by dehydrating [[dimethylglyoxime]].<ref>{{OrgSynth | author = Lyell C. Behr and John T. Brent | title = Dimethylfurazan | collvol = 4 | collvolpages = 342 | prep = cv5p0342 | year = 1963}}</ref> A variety of related derivatives are known, including diphenyl- and methylethylfurazan.

;Carboxylic acid derivatives

[[Potassium permanganate]] oxidizes 3,4-dimethylfurazan first to methylfurazancarboxylic acid and then to furazandicarboxylic acid. By warming oxyfurazan acetic acid with excess of potassium permanganate, oxyfurazancarboxylic acid is obtained. It crystallizes as prisms ([[melting point|m.p.]] 175&nbsp;°C). Furazancarboxylic acid (m.p.&nbsp;107&nbsp;°C) is prepared by oxidation of furazanpropionic acid with potassium permanganate. It dissolves in base to give nitrosocyanacetate.

;Diaminofurazan

;Furoxan

[[Furoxan]] may be formed by dimerization of nitrile oxides

*{{cite EB1911 |wstitle=Furazanes|volume=11|page=357}}