Wikipedia:WikiProject Chemicals/Chembox validation/VerifiedDataSandbox and Pyridazine: Difference between pages

{{short description|Heterocyclic organic compound (C4H4N2)}}

| = changed

| verifiedrevid =

| ImageFile = Pyridazine 2D numbers.svg

| ImageClass = skin-invert-image

| ImageSize = 135

| ImageAlt = Skeletal formula with numbering convention

| ImageFileL1=Pyridazine.png

| ImageClassL1 = bg-transparent

| ImageNameL1 = C=black, H=white, N=blue

| ImageAltL1 = Pyridazine molecule

|=Pyridazine

| ImageClassR1 = bg-transparent

| ImageNameR1 = C=black, H=white, N=blue

| ImageAltR1 = Pyridazine molecule

| PIN = Pyridazine<ref name=iupac2013>{{cite book | title = Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book) | publisher = [[Royal Society of Chemistry|The Royal Society of Chemistry]] | date = 2014 | location = Cambridge | page = 141 | doi = 10.1039/9781849733069-FP001 | isbn = 978-0-85404-182-4| chapter = Front Matter }}</ref>

| SystematicName = 1,2-Diazabenzene

| OtherNames = 1,2-Diazine<br />Orthodiazine<br />Oizine

|Section1={{Chembox Identifiers

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo=289-80-5

| Beilstein = 103906

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

| EINECS = 206-025-5

| Gmelin = 49310

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

| UNII = 449GLA0653

| PubChem = 9259

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 30954

| SMILES = n1ncccc1

}}

|Section2={{Chembox Properties

| C=4|H=4|N=2

| Appearance=Colorless liquid

| Density=1.107 g/cm³

| MeltingPtC=-8

| BoilingPtC=208

| Solubility= miscible

| SolubleOther = miscible in [[dioxane]], [[ethanol]] <br> soluble in [[benzene]], [[diethyl ether]] <br> negligible in [[cyclohexane]], [[ligroin]]

| pKa =

| pKb =

| RefractIndex = 1.52311 (23.5 °C)

}}

|Section3={{Chembox Thermochemistry

| DeltaHf = 224.9 kJ/mol

}}

|Section7={{Chembox Hazards

| GHS_ref=<ref>{{cite web |title=Pyridazine |url=https://pubchem.ncbi.nlm.nih.gov/compound/9259#section=Safety-and-Hazards |website=pubchem.ncbi.nlm.nih.gov |language=en}}</ref>

| GHSPictograms = {{GHS07}}

| GHSSignalWord = Warning

| HPhrases = {{H-phrases|302|315|319|335}}

| PPhrases = {{P-phrases|261|264|264+265|270|271|280|301+317|302+352|304+340|305+351+338|319|321|330|332+317|337+317|362+364|403+233|405|501}}

| MainHazards=

| FlashPtC= 85

| AutoignitionPt =

}}

|Section8={{Chembox Related

| OtherCompounds = {{unbulleted list|[[pyridine]]|[[pyrimidine]]|[[pyrazine]]}}

}}

'''Pyridazine''' is an [[aromatic]], [[heterocyclic]], [[organic compound]] with the molecular formula {{chem2|C4H4N2}}. It contains a six-membered [[Ring (chemistry)|ring]] with two adjacent [[nitrogen]] atoms.<ref>{{cite journal | last1 = Gumus | first1 = S. | year = 2011 | title = A computational study on substituted diazabenzenes | url = http://journals.tubitak.gov.tr/chem/issues/kim-11-35-5/kim-35-5-11-1012-875.pdf | journal = Turk J Chem | volume = 35 | pages = 803–808 | access-date = 2014-04-10 | archive-url = https://web.archive.org/web/20160303181258/http://journals.tubitak.gov.tr/chem/issues/kim-11-35-5/kim-35-5-11-1012-875.pdf | archive-date = 2016-03-03 | url-status = dead }}</ref> It is a colorless liquid with a [[boiling point]] of 208&nbsp;°C. It is [[Structural isomer|isomeric]] with two other [[diazine]] ({{chem2|C4H4N2}}) rings, [[pyrimidine]] and [[pyrazine]].

==Occurrence==

Pyridazines are rare in nature, possibly reflecting the scarcity of naturally occurring [[hydrazines]], common building blocks for the synthesis of these heterocycles. The pyridazine structure is a popular [[pharmacophore]] which is found within a number of herbicides such as [[credazine]], [[pyridafol]] and [[pyridate]]. It is also found within the structure of several drugs such as [[cefozopran]], [[cadralazine]], [[minaprine]], [[pipofezine]], and [[hydralazine]].

==Synthesis==

In the course of his classic investigation on the [[Fischer indole synthesis]], Emil Fischer prepared the first pyridazine via the condensation of [[phenylhydrazine]] and [[levulinic acid]].<ref>{{cite journal | last1 = Fischer | first1 = E. | year = 1886 | title = Indole aus Phenylhydrazin | url = https://zenodo.org/record/1427407| journal = Justus Liebigs Annalen der Chemie | volume = 236 | issue = 1–2| pages = 126–151 | doi = 10.1002/jlac.18862360107 }}</ref> The parent heterocycle was first prepared by oxidation of [[benzocinnoline]] to the pyridazinetetracarboxylic acid followed by [[decarboxylation]]. A better route to this otherwise esoteric compound starts with the [[maleic hydrazide]]. These heterocycles are often prepared via condensation of 1,4-[[diketone]]s or 4-ketoacids with [[hydrazine]]s.<ref>{{cite book | last1 = Tišler | first1 = M. | last2 = Stanovnik | first2 = B. | title = Advances in Heterocyclic Chemistry Volume 9 | chapter = Pyridazines | year = 1968 | volume = 9 | pages = 211–320 | doi = 10.1016/S0065-2725(08)60374-8 | isbn = 9780120206094}}</ref>

==References==

<references/>

{{Simple aromatic rings}}

{{Authority control}}

[[Category:Pyridazines| ]]

[[Category:Simple aromatic rings]]