methyl isothiocyanate
{{chembox
|Verifiedfields = changed
|verifiedrevid = 415837766
|ImageFileL1=
|ImageFileR1=
|ImageFile1 = Methyl isothiocyanate.png
|ImageSize1 = 120px
|ImageFileL2 = Methyl isothiocyanate-3D-balls-by-AHRLS-2012.png
|ImageSizeL2 = 120px
|ImageFileR2 = Methyl isothiocyanate-3D-vdW-by-AHRLS-2012.png
|ImageSizeR2 = 120px
|PIN= Isothiocyanatomethane
|OtherNames= MITC, Trapex, Trapex, Vorlex, MITC-Fume, MIT, Morton EP-161E, WN 12
|Section1={{Chembox Identifiers
|CASNo_Ref = {{cascite|correct|CAS}}
|CASNo=556-61-6
|ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
|ChemSpiderID = 10694
|ChEBI_Ref = {{ebicite|correct|EBI}}
|ChEBI = 78337
|ChEMBL_Ref = {{ebicite|correct|EBI}}
|ChEMBL = 396000
|EINECS = 209-132-5
|PubChem = 11167
|KEGG_Ref = {{keggcite|correct|kegg}}
|KEGG = C18587
|UNII_Ref = {{fdacite|correct|FDA}}
|UNII = RWE2M5YDW1
|UNNumber = 2477
|InChI = 1/C2H3NS/c1-3-2-4/h1H3
|InChIKey = LGDSHSYDSCRFAB-UHFFFAOYAS
|StdInChI_Ref = {{stdinchicite|correct|chemspider}}
|StdInChI = 1S/C2H3NS/c1-3-2-4/h1H3
|StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
|StdInChIKey = LGDSHSYDSCRFAB-UHFFFAOYSA-N
|SMILES = S=C=NC
}}
|Section2={{Chembox Properties
|C=2 | H=3 | N=1 | S=1
|MolarMass= 73.12
|Appearance= colourless solid
|Density= 1.07 g cm−3
|MeltingPtC= 31
|BoilingPtC= 117
|Solubility= 8.2g/l
}}
|Section3={{Chembox Hazards
|ExternalSDS = [https://fscimage.fishersci.com/msds/07204.htm ACC# 07204]
|NFPA-H = 3
|NFPA-F = 1
|NFPA-R = 1
|GHSPictograms = {{GHS05}}{{GHS06}}{{GHS07}}{{GHS09}}
|GHSSignalWord = Danger
|HPhrases = {{H-phrases|301|314|317|331|410}}
|PPhrases = {{P-phrases|260|261|264|270|271|272|273|280|301+310|301+330+331|302+352|303+361+353|304+340|305+351+338|310|311|321|330|333+313|363|391|403+233|405|501}}
}}
|Section4={{Chembox Structure
|Dipole = 3.528 D
}}
|Section5={{Chembox Related
|OtherCompounds = Methyl isocyanate
Methyl thiocyanate
}}
}}
Methyl isothiocyanate is the organosulfur compound with the formula CH3N=C=S. This low melting colorless solid is a powerful lachrymator. As a precursor to a variety of valuable bioactive compounds, it is the most important organic isothiocyanate in industry.{{Ullmann | author = Romanowski, F. | author2 = Klenk, H. | title = Thiocyanates and Isothiocyanates, Organic | doi = 10.1002/14356007.a26_749}}
Synthesis
It is prepared industrially by two routes. Annual production in 1993 was estimated to be 4,000 tonnes.{{cn|date=May 2021}} The main method involves the thermal rearrangement of methyl thiocyanate:
:CH3S−C≡N → CH3N=C=S
It is also prepared via with the reaction of methylamine with carbon disulfide followed by oxidation of the resulting dithiocarbamate with hydrogen peroxide. A related method is useful to prepare this compound in the laboratory.{{ OrgSynth | author = Moore, M. L. | author2 = Crossley, F. S. | title = Methyl Isothiocyanate | year = 1941 | volume = 21 | pages = 81 | collvol = 3 | collvolpages = 599 | prep = CV3P0599 }}
MITC forms naturally upon the enzymatic degradation of glucocapparin, a glucoside found in capers.
Reactions
A characteristic reaction is with amines to give methyl thioureas:
:CH3NCS + R2NH → R2NC(S)NHCH3
:Image:MITC-to-thiourea-2D.png
Other nucleophiles add similarly.
Applications
Solutions of MITC are used in agriculture as soil fumigants, mainly for protection against fungi and nematodes.{{cite book |doi=10.1002/14356007.a17_125.pub2|chapter=Nematicides |title=Ullmann's Encyclopedia of Industrial Chemistry |year=2008 |last1=Hartwig |first1=Jürgen |last2=Sommer |first2=Herbert |last3=Müller |first3=Franz |isbn=978-3527306732 }}
MITC is a building block for the synthesis of 1,3,4-thiadiazoles, which are heterocyclic compounds used as herbicides. Commercial products include "Spike", "Ustilan," and "Erbotan."
Well known pharmaceuticals prepared using MITC include Zantac and Tagamet. Suritozole is a third example.
MITC is used in the Etasuline patent (Ex2{{US patent|3417085}}), although the compound is question (Ex6) is with EITC.
Safety
MITC is a dangerous lachrymator as well as being poisonous.
See also
References
{{Reflist}}
{{Cruciferous Biochemistry}}