Metalaxyl
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IUPAC name
Methyl 2-[N-(2,6-dimethylphenyl)(methoxy)acetamido]propanoate
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Other names
Methyl N-(2,6-dimethylphenyl)-N-(2-methoxyacetyl)alaninate
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Identifiers | |
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3D model (JSmol)
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ChEBI |
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ChemSpider |
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ECHA InfoCard | 100.055.418 Edit this at Wikidata |
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PubChem CID
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CompTox Dashboard (EPA)
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Properties | |
C15H21NO4 | |
Molar mass | 279.33 g/mol |
Appearance | Fine white powder |
Density | 1.20g/cm3 at 20 °C |
Melting point | 71 to 72 °C (160 to 162 °F; 344 to 345 K)[2] |
Boiling point | 295.9 °C (564.6 °F; 569.0 K) at 760 mm Hg |
8,400 mg/L at 22 °C | |
log P | 1.65 (octanol/water)[1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Metalaxyl is an acylalanine fungicide with systemic function.[3] Its chemical name is methyl N-(methoxyacetyl)-N-(2,6-xylyl)-DL-alaninate. It can be used to control Pythium in a number of vegetable crops, and Phytophthora in peas. Metalaxyl-M is the ISO common name[4] and Ridomil Gold is the trade name for the optically pure (-) / D / R active stereoisomer, which is also known as mefenoxam.[5]
It is the active ingredient in the seed treatment agent Apron XL LS.[6]
The fungicide has suffered severe resistance problems. The fungicide was marketed for use against Phytophthora infestans . However, in the summer of 1980, in the Republic of Ireland, the crop was devastated by a potato blight epidemic after a resistant race of the oomycete appeared.[7] Irish farmers later successfully sued the company for their losses.[citation needed ] Maximum pesticide residue limits for the EU/UK are set at 0.5 mg/kg for oranges and 1.0 mg/kg for apples.[citation needed ] As early as 1998 Pythium was known to be widely developing resistance to metalaxyl[8] which was the most effective control at the time.[8] Various Pythium populations have been known to have resistance to mefenoxam since the 1980s[9] and metalaxyl since 1984.[10] There is wide variability in resistance/sensitivity between Pythium species, with some populations showing complete ineffectiveness.[9]
Synthesis
[edit ]The first synthesis of metalaxyl was disclosed in patents filed by Ciba Geigy.[11]
2,6-Xylidine is alkylated with methyl 2-bromopropionate to give an alanine derivative. This is further reacted with the acid chloride of methoxyacetic acid to yield racemic metalaxyl.[11] [12] The homochiral, single-isomer version of the chemical, which retains all its fungicidal activity, has been manufactured.[13]
References
[edit ]- ^ Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 134
- ^ O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. 13th Edition, Whitehouse Station, NJ: Merck and Co., Inc., 2001., p. 1058
- ^ Sukul, P; Spiteller, M (2000). "Metalaxyl: persistence, degradation, metabolism, and analytical methods". Reviews of Environmental Contamination and Toxicology. 164: 1–26. PMID 12587832.
- ^ "Compendium of Pesticide Common Names: metalaxyl". BCPC.
- ^ Monkiedje, Adolphe; Spiteller, Michael (2002). "Effects of the phenylamide fungicides, mefenoxam and metalaxyl, on the microbiological properties of a sandy loam and a sandy clay soil". Biology and Fertility of Soils. 35 (6): 393–398. doi:10.1007/s00374-002-0485-1. S2CID 22642870.
- ^ "bmz10s02.pdf" (PDF). Government of Manitoba. Archived from the original (PDF) on 2007年09月30日.
- ^ Working on potato blight in Northern Ireland
- ^ a b "Survey of Pythium Isolates for Resistance to Subdue (metalaxyl)" (PDF). UMass Amherst . Retrieved 2020年11月23日.
- ^ a b Del Castillo Múnera, Johanna; Hausbeck, Mary K. (2016). "Characterization of Pythium Species Associated With Greenhouse Floriculture Crops in Michigan". Plant Disease . 100 (3). American Phytopathological Society: 569–576. doi:10.1094/pdis-03-15-0296-re . ISSN 0191-2917. PMID 30688597.
- ^ Sanders, P. L. (1984). "Failure of Metalaxyl to Control Pythium Blight on Turfgrass in Pennsylvania". Plant Disease . 68 (1). American Phytopathological Society: 776. doi:10.1094/pd-68-776. ISSN 0191-2917.
- ^ a b GB patent 1500581, "Substituted amides and their use as fungicides", issued 1978年02月08日, assigned to Ciba-Geigy AG
- ^ Ishitani, Haruro; Yu, Zhibo; Ichitsuka, Tomohiro; Koumura, Nagatoshi; Onozawa, Shun-ya; Sato, Kazuhiko; Kobayashi, Shū (2022). "Two-Step Continuous-Flow Synthesis of Fungicide Metalaxyl through Catalytic C−N Bond-Formation Processes". Advanced Synthesis & Catalysis. 364: 18–23. doi:10.1002/adsc.202100898.
- ^ Blaser, Hans-Ulrich; Spindler, Felix (1997). "Enantioselective catalysis for agrochemicals. The case histories of (S)–metolachlor, (R)–metalaxyl and clozylacon". Topics in Catalysis. 4 (3/4): 275–282. doi:10.1023/A:1019164928084.
External links
[edit ]- Metalaxyl in the Pesticide Properties DataBase (PPDB)
- Metalaxyl-M in the Pesticide Properties DataBase (PPDB)