Sedimentation potential: Difference between revisions
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{{chembox | |||
| verifiedrevid = 443345092 | |||
|Reference=<ref>''Merck Index'', 11th Edition, '''5905'''</ref> | |||
|ImageFile=Methomyl Structural Formulae .V.1.svg | |||
|ImageSize=200px | |||
|IUPACName=(''E'',''Z'')-methyl ''N''-{[(methylamino)carbonyl]oxy}ethanimidothioate | |||
|OtherNames=Lannate, Mesomile, Methomex, Nudrin | |||
|Section1= {{Chembox Identifiers | |||
| CASNo_Ref = {{cascite|correct|CAS}} | |||
| CASNo=16752-77-5 | |||
| PubChem=5353758 | |||
| SMILES=CC(=NOC(=O)NC)SC | |||
}} | |||
|Section2= {{Chembox Properties | |||
|C=5|H=10|N=2|O=2|S=1 | |||
| MolarMass=162.20 | |||
| Appearance=Crystals | |||
| Odor=Slight, sulfur-like<ref>[http://www.cdc.gov/niosh/npg/npgd0387.html CDC - NIOSH Pocket Guide to Chemical Hazards]</ref> | |||
| Density=1.2946 g/cm<sup>3</sup> | |||
| MeltingPt=78-79 °C | |||
| BoilingPt= | |||
| Solubility=58 g/L | |||
}} | |||
|Section3= {{Chembox Hazards | |||
| MainHazards= | |||
| FlashPt= | |||
| Autoignition= | |||
}} | |||
}} | |||
'''Methomyl''' is a [[carbamate]] [[insecticide]]. It was introduced in 1966, but its use is restricted because of its high toxicity to humans.<ref>[http://extoxnet.orst.edu/pips/methomyl.htm Methomyl] at Extension Toxicology Network</ref> Its current primary use is on [[alfalfa]] for [[forage]].<ref>[http://www.pesticideinfo.org/Detail_ChemUse.jsp?Rec_Id=PC35109 Methomyl] at PAN Pesticide Database</ref> | |||
The EU and UK have imposed these restrictions by allowing a maximum pesticide residue limit of 0.02 mg/kg for apples and oranges.{{Citation needed|date=February 2012}} 0.02 mg/kg is the limit of detection. | |||
It has been found in residues on vegetables and spices in Thailand exceeding safety standards in 2012, due to not being listed on the [[Dangerous Substances Act]], along with [[carbofuran]], [[dicrotophos]] and [[EPN (insecticide)|EPN]].<ref>{{cite news | url = http://www.bangkokpost.com/news/local/302017/cancer-causing-chemical-residues-found-in-vegetables | title = Cancer-causing chemical residues found in vegetables | publisher = Bangkok Post | date = 12/07/2012}}</ref> | |||
Methomyl is the active ingredient in commercial fly bait granules which are mixed with a [[cola]] drink to kill bothersome [[raccoon]], [[skunk]] and [[opossum]]. Using methomyl in this "off-label" way may be against the law in some of the United States. <ref>[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)]</ref><ref>[http://www.indianaeconomicdigest.net/main.asp?SectionID=31&SubSectionID=68&ArticleID=65569 Farm stores promoted poisoning raccoons, state chemist says]</ref> | |||
==Synthesis== | |||
Methomyl can be produced by reaction of [[methyl isocyanate]] and [[methylthioacetaldoxime]](also known as methomyl oxime) | |||
First preparing ester | |||
<math>{{\text{H}}_{\text{3}}}\text{C-}\underset{\underset{\text{O}}{\mathop{\text{ }\!\!|\!\!\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{\text{C}}}\,\text{-OH+HS-C}{{\text{H}}_{\text{3}}}\xrightarrow{\text{30--50 }\!\!~\!\!\text{ }\!\!{}^\circ\!\!\text{ C}\text{,-}{{\text{H}}_{2}}O}{{\text{H}}_{\text{3}}}\text{C-}\underset{\underset{\text{O}}{\mathop{\text{ }\!\!|\!\!\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{\text{C}}}\,\text{-S-C}{{\text{H}}_{\text{3}}}</math> | |||
Second preparing oxime from ester | |||
<math>{{\text{H}}_{\text{3}}}\text{C-}\underset{\underset{\text{O}}{\mathop{\text{ }\!\!|\!\!\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{\text{C}}}\,\text{-S-C}{{\text{H}}_{\text{3}}}\text{+}{{\text{H}}_{\text{2}}}\text{NOH}\xrightarrow{-{{H}_{2}}O}\text{HO-N=}\underset{\text{C}{{\text{H}}_{\text{3}}}}{\mathop{\underset{\text{ }\!\!|\!\!\text{ }}{\mathop{\text{C}}}\,}}\,\text{-S-C}{{\text{H}}_{\text{3}}}</math> | |||
Third preparing product from isocyanate and oxime. | |||
<math>{{\text{H}}_{\text{3}}}\text{C-N=C=O+HO-N=}\underset{\text{C}{{\text{H}}_{\text{3}}}}{\mathop{\underset{\text{ }\!\!|\!\!\text{ }}{\mathop{\text{C}}}\,}}\,\text{-S-C}{{\text{H}}_{\text{3}}}\xrightarrow{\text{C}{{\text{H}}_{\text{2}}}\text{C}{{\text{l}}_{\text{2}}}\text{,30--50 }\!\!~\!\!\text{ }\!\!{}^\circ\!\!\text{ C}}\text{Methomyl}</math> | |||
==References== | |||
<references/> | |||
{{Cholinergics}} | |||
{{insecticides}} | |||
[[Category:Carbamate insecticides]] | |||
[[Category:Anticholinesterases]] | |||
[[Category:Endocrine disruptors]] |
Revision as of 05:08, 8 May 2013
{{chembox | verifiedrevid = 443345092 |Reference=[1] |ImageFile=Methomyl Structural Formulae .V.1.svg |ImageSize=200px |IUPACName=(E,Z)-methyl N-{[(methylamino)carbonyl]oxy}ethanimidothioate |OtherNames=Lannate, Mesomile, Methomex, Nudrin |Section1= Template:Chembox Identifiers |Section2= Template:Chembox Properties |Section3= Template:Chembox Hazards }}
Methomyl is a carbamate insecticide. It was introduced in 1966, but its use is restricted because of its high toxicity to humans.[2] Its current primary use is on alfalfa for forage.[3] The EU and UK have imposed these restrictions by allowing a maximum pesticide residue limit of 0.02 mg/kg for apples and oranges.Potter or Ceramic Artist Truman Bedell from Rexton, has interests which include ceramics, best property developers in singapore developers in singapore and scrabble. Was especially enthused after visiting Alejandro de Humboldt National Park. 0.02 mg/kg is the limit of detection.
It has been found in residues on vegetables and spices in Thailand exceeding safety standards in 2012, due to not being listed on the Dangerous Substances Act, along with carbofuran, dicrotophos and EPN.[4]
Methomyl is the active ingredient in commercial fly bait granules which are mixed with a cola drink to kill bothersome raccoon, skunk and opossum. Using methomyl in this "off-label" way may be against the law in some of the United States. [5][6]
Synthesis
Methomyl can be produced by reaction of methyl isocyanate and methylthioacetaldoxime(also known as methomyl oxime)
First preparing ester
Second preparing oxime from ester
Third preparing product from isocyanate and oxime.
References
- ↑ Merck Index, 11th Edition, 5905
- ↑ Methomyl at Extension Toxicology Network
- ↑ Methomyl at PAN Pesticide Database
- ↑ Template:Cite news
- ↑ Conservation Warden Warns: Fly bait to control wild animals – illegal and a bad idea (Wisconsin Department of Natural Resources)
- ↑ Farm stores promoted poisoning raccoons, state chemist says