Methyl isocyanide: Difference between revisions

{{distinguish|Methyl isocyanate}}

{{Chembox

| Watchedfields = changed

| verifiedrevid = 455280169

| IUPACName = Isocyanomethane

| OtherNames = {{ubl|Methyl isocyanide| Isoacetonitrile| Methylisonitrile| Isomethanenitrile| Methaneisonitrile}}

|Section1={{Chembox Identifiers

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

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

| UNII = B5B6DXM7GG

| EC_number = 209-806-9

}}

|Section2={{Chembox Properties

| H=3 | N=1 | C=2

| Appearance = Colorless liquid

| Density = 0.69 g/mL

| MeltingPtC = −45

| MeltingPt_notes =

| BoilingPtC = 59 to 60

| BoilingPt_notes =

| Solubility = Miscible

| SolubleOther =

| pKb =

}}

|Section7={{Chembox Hazards

| NFPA-S =

| GHSPictograms = {{GHS07}}{{GHS08}}

| GHSSignalWord = Warning

| HPhrases = {{H-phrases|302|312|332|373}}

| PPhrases = {{P-phrases|260|261|264|270|271|280|301+312|302+352|304+312|304+340|312|314|322|330|363|501}}

| AutoignitionPt =

| PEL =

}}

|Section8={{Chembox Related

| OtherFunction =

| OtherFunction_label =

| OtherCompounds = [[acetic acid]], [[acetamide]], [[ethylamine]], [[Acetonitrile]]}}

'''Methyl isocyanide''' or '''isocyanomethane''' is an [[organic compound]] and a member of the [[isocyanide]] family. This colorless liquid is isomeric and isoelectronic to methyl cyanide ([[acetonitrile]]), but its reactivity is very different. In contrast to the faintly sweet, ethereal odor of acetonitrile, the smell of methyl isocyanide, like that of other simple volatile isocyanides, is distinctly penetrating and vile.<ref>{{cite book|url=https://archive.org/details/gergel_isopropyl_bromide|title=Excuse me sir, would you like to buy a kilo of isopropyl bromide?|first=Max&nbsp;G.|last=Gergel|author-link=Max Gergel|date=March 1977|publisher=Pierce Chemical|page=115}}</ref> Methyl isocyanide is mainly used for making 5-membered [[heterocyclic]] rings. The C-N distance in methyl isocyanide is very short, 1.158 Å as is characteristic of isocyanides.

<ref>{{cite journal | last1=Kessler | first1=Myer | last2=Ring | first2=Harold | last3=Trambarulo | first3=Ralph | last4=Gordy | first4=Walter | title=Microwave Spectra and Molecular Structures of Methyl Cyanide and Methyl Isocyanide | journal=Physical Review | publisher=American Physical Society (APS) | volume=79 | issue=1 | date=1950-07-01 | issn=0031-899X | doi=10.1103/physrev.79.54 | pages=54–56| bibcode=1950PhRv...79...54K }}</ref>

==Preparation and uses==

Methyl isocyanide was first prepared by [[A. Gautier]] by reaction of [[silver cyanide]] with [[methyl iodide]].<ref>{{cite journal | author = Gautier, A. | title = Ueber eine neue Reihe von Verbindungen, welche mit den Cyanwasserstoffsäure-Aethern isomer sind | journal = [[Justus Liebigs Annalen der Chemie]] | year = 1868 | volume = 146 | issue = 1 | pages = 119–124 | doi = 10.1002/jlac.18681460107 | url = https://zenodo.org/record/1427279 }}</ref><ref>{{cite journal | author = Gautier, A. | title = Des Nitriles des Acides Gras: Deuxième Partie - Des Carbylamines | journal = [[Annales de Chimie et de Physique]] | year = 1869 | volume = 17 | page = 203 | url = http://gallica.bnf.fr/ark:/12148/bpt6k34827s/f102.image.langEN }}</ref> The common method for preparing methyl isocyanides is the dehydration of [[N-Methylformamide|''N''-methylformamide]].<ref>{{OrgSynth | author = R. E. Schuster, James E. Scott, and Joseph Casanova, Jr | title = Methyl isocyanide | year = 1966 | volume = 46 | pages = 75 | DOI = 10.15227/orgsyn.046.0075 }}</ref> Many metal cyanides react with methylating agents to give complexes of methyl isocyanide.<ref>{{cite journal|doi=10.1021/cr00019a016|title=Emergence of a CNH and Cyano Complex Based Organometallic Chemistry|journal=Chemical Reviews|volume=93|issue=3|pages=1243–1280|year=1993|last1=Fehlhammer|first1=Wolf P.|last2=Fritz|first2=Marcus.}}</ref> This kind of reactivity has been invoked as being relevant to the origin of life.<ref>{{Cite journal|last1=Mariani|first1=Angelica|last2=Russell|first2=David|last3=Javelle|first3=Thomas|last4=Sutherland|first4=John|year=2018|title=A Light-Releasable Potentially Prebiotic Nucleotide Activating Agent|journal=Journal of the American Chemical Society|volume=140|issue=28|pages=8657–8661|doi=10.1021/jacs.8b05189|pmid=29965757|pmc=6152610}}</ref>

Methyl isocyanide is useful for the preparation of diverse heterocycles. It is often used to prepare [[transition metal isocyanide complexes]].<ref>{{ cite encyclopedia |author1=Eckert, H. |author2=Nestl, A. |author3=Ugi, I. |title=Methyl Isocyanide | encyclopedia = Encyclopedia of Reagents for Organic Synthesis | year = 2001 | publisher = John Wiley & Sons | doi = 10.1002/047084289X.rm198 |isbn=0471936235 }}</ref>

== Safety ==

Methyl isocyanide is very endothermic (Δ_f''H''^⦵(g) = +150.2 kJ/mol, 3.66 kJ/g) and can isomerize explosively to acetonitrile.<ref>{{Cite journal|last1=Clothier|first1=P. Q. E.|last2=Glionna|first2=M. T. J.|last3=Pritchard|first3=H. O.|date=July 1985|title=Thermal explosions of methyl isocyanide in spherical vessels|url=https://pubs.acs.org/doi/pdf/10.1021/j100260a008|journal=The Journal of Physical Chemistry|volume=89|issue=14|pages=2992–2996|doi=10.1021/j100260a008|issn=0022-3654}}</ref> A sample exploded when heated in a sealed ampoule, and during redistillation at 59&nbsp;°C and 1&nbsp;bar, a drop of liquid fell back into the dry boiler flask and exploded violently. The explosive decomposition of methyl isocyanide has been studied in detail.<ref>{{Cite book|title=Bretherick's Handbook of Reactive Chemical Hazards {{!}} ScienceDirect|url=https://www.sciencedirect.com/book/9780081009710/brethericks-handbook-of-reactive-chemical-hazards|access-date=2022-02-23|isbn=9780081009710 |language=en |last1=Urben |first1=Peter |date=22 May 2017 |publisher=Elsevier Science }}</ref>

{{reflist}}

* {{ cite web | url = http://webbook.nist.gov/cgi/cbook.cgi?ID=593-75-9&Units=SI | title = WebBook page for C₂H₃N }}

{{Molecules detected in outer space}}

[[Category:Ligands]]

[[Category:Foul-smelling chemicals]]

[[Category:Methyl compounds]]