methomyl
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 443345092
| Reference =Merck Index, 11th Edition, 5905
| ImageFileL1 = (E)-Methomyl formula structural.svg
| ImageSizeL1 = 170
| ImageCaptionL1 = (E)-Methomyl
| ImageAltL1 = Skeletal formula of (E)-Methomyl
| ImageFileR1 = (E)-Methomyl molecule spacefill.png
| ImageSizeR1 = 120
| ImageAltR1 = Space-filling model of (E)-Methomyl
| ImageFileL2 = (Z)-Methomyl formula structural.svg
| ImageSizeL2 = 170
| ImageCaptionL2 = (Z)-Methomyl
| ImageAltL2 = Skeletal formula of (Z)-Methomyl
| ImageFileR2 = (Z)-Methomyl molecule spacefill.png
| ImageSizeR2 = 120
| ImageAltR2 = Space-filling model of (E)-Methomyl
| IUPACName =(E,Z)-methyl N-
| OtherNames =Lannate, Mesomile, Methomex, Nudrin
|Section1={{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo =16752-77-5
| PubChem =5353758
| ChEBI_Ref = {{ebicite|changed|EBI}}
| ChEBI = 6835
| ChEMBL_Ref = {{ebicite|changed|EBI}}
| ChEMBL = 552761
| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
| ChemSpiderID = 3966
| SMILES = CNC(=O)ON=C(C)SC
| InChI = 1/C5H10N2O2S/c1-4(10-3)7-9-5(8)6-2/h1-3H3,(H,6,8)
| InChIKey = UHXUZOCRWCRNSJ-UHFFFAOYAU
| StdInChI_Ref = {{stdinchicite|changed|chemspider}}
| StdInChI = 1S/C5H10N2O2S/c1-4(10-3)7-9-5(8)6-2/h1-3H3,(H,6,8)
| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
| StdInChIKey = UHXUZOCRWCRNSJ-UHFFFAOYSA-N
}}
|Section2={{Chembox Properties
| C=5 | H=10 | N=2 | O=2 | S=1
| MolarMass =162.20
| Appearance =White crystalline solid
| Density =1.2946 g/cm3
| MeltingPtC = 78 to 79
| MeltingPt_notes =
| BoilingPt =
| Solubility =58 g/L
| VaporPressure = 0.00005 mmHg (25°C)
}}
|Section3={{Chembox Hazards
| MainHazards =
| FlashPt_notes = Noncombustible
| AutoignitionPt =
| IDLH = N.D.{{PGCH|0387}}
}}
}}
Methomyl is a carbamate insecticide introduced in 1966. It is highly toxic to humans, livestock, pets, and wildlife.[http://extoxnet.orst.edu/pips/methomyl.htm Methomyl] at Extension Toxicology Network
The EU imposed a pesticide residue limit of 0,01 mg/kg for all fruit and vegetables.{{Cite web|url=https://ec.europa.eu/food/plant/pesticides/eu-pesticides-database/start/screen/mrls/details?lg_code=EN&pest_res_id_list=157&product_id_list= |title=EU pesticides database}}
Methomyl is a common active ingredient in commercial fly bait, for which the label instructions in the United States warn that "It is a violation of Federal Law to use this product in a manner inconsistent with its labeling." "Off-label" uses and other uses not specifically targeted at problem insects are illegal, dangerous, and ill-advised.[http://dnr.wi.gov/news/BreakingNews_Print.asp?id=481 Conservation Warden Warns: Fly bait to control wild animals – illegal and a bad idea (Wisconsin Department of Natural Resources)]{{Cite web |url=http://www.indianaeconomicdigest.net/main.asp?SectionID=31&SubSectionID=68&ArticleID=65569 |title=Farm stores promoted poisoning raccoons, state chemist says |access-date=2012-08-09 |archive-date=2015-09-24 |archive-url=https://web.archive.org/web/20150924034421/http://www.indianaeconomicdigest.net/main.asp?SectionID=31&SubSectionID=68&ArticleID=65569 |url-status=dead }}
Use
Methomyl is a broad-spectrum insecticide that is used to kill insect pests.{{cite tech report |institution=U. S. Environmental Protection Agency |title= EPA R.E.D. FACTS - Methomyl|date= December 1998 |url= http://www.epa.gov/opp00001/reregistration/REDs/factsheets/0028fact.pdf|number= EPA-738-F-98-019}} Methomyl is registered for commercial/professional use under certain conditions on sites including field, vegetable, and orchard crops; turf (sod
farms only); livestock quarters; commercial premises; and refuse containers. Products containing 1% Methomyl are available to the general public for retail sale, but more potent formulations are classified as restricted-use pesticides: not registered for homeowner or non-professional application. However, Heliothis virescens developed a resistance to methomyl within 5 years.{{Cite journal|last=Blanco|first=Carlos|date=2012|title=Heliothis virescens and Bt cotton in the United States|journal=GM Crops & Food: Biotechnology in Agriculture and the Food Chain|volume=3|issue=3|pages=201–212|doi=10.4161/gmcr.21439|pmid=22892654|doi-access=free}} Other species like Helicoverpa assulta also developed resistance after exposure.{{Cite journal|last1=Wang|first1=Kai-Yun|last2=Zhang|first2=Yong|last3=Wang|first3=Hong-Yan|last4=Xia|first4=Xiao-Ming|last5=Liu|first5=Tong-Xian|date=2010-01-01|title=Influence of three diets on susceptibility of selected insecticides and activities of detoxification esterases of Helicoverpa assulta (Lepidoptera: Noctuidae)|journal=Pesticide Biochemistry and Physiology|volume=96|issue=1|pages=51–55|doi=10.1016/j.pestbp.2009.09.003}}
Toxicity
In acute toxicity testing, methomyl is placed in EPA Toxicity Category I (the highest toxicity category out of four) via the oral route and in eye irritation studies. It is in lower Toxicity Categories for inhalation (Category II), acute dermal effects (Category III), and acute skin irritation (Category IV). Methomyl is not likely to be a carcinogen (EPA carcinogen Category E).
Ecotoxicity
Methomyl has low persistence in the soil environment, with a reported half-life of approximately 14 days.{{cite book |last= Howard|first= P. H. |date= 1991|title= Handbook of Environmental Fate and Exposure Data for Organic Chemicals: Pesticides|location= Chelsea, MI|publisher= Lewis Publishers|pages= 3–15}} Because of its high solubility in water, and low affinity for soil binding methomyl may have potential for groundwater contamination. The estimated aqueous half-life for the insecticide is 6 days in surface water and over 25 weeks in groundwater.
Synthesis
First prepare thioester:
Second prepare oxime from thioester:
Third prepare product from methyl isocyanate and the finished oxime:
Trade names
Common names for methomyl include metomil and mesomile. Trade names include {{not a typo|Acinate}}, Agrinate, DuPont 1179, Flytek, Kipsin, Lannate, Lanox, Memilene, Methavin, Methomex, Nudrin, NuBait, Pillarmate and SD 14999 {{Cite web|url=http://extoxnet.orst.edu/pips/methomyl.htm|title=Extoxnet Pip - Methomyl}}
References
{{reflist}}
External links
- {{PPDB|458}}
{{Insecticides}}
{{Acetylcholine metabolism and transport modulators}}
{{Authority control}}
Category:Acetylcholinesterase inhibitors