Metalaxyl

Structural formula
Structural formula without stereochemistry
General
Surname	Metalaxyl
other names	( RS ) -Methyl- N - (2,6-dimethylphenyl) - N - (methoxyacetyl) - DL -alaninate ( IUPAC )
Molecular formula	C 15 H 21 NO 4
Brief description	white solid
External identifiers / databases
CAS number 57837-19-1 EC number 260-979-7 ECHA InfoCard 100.055.418 PubChem 42586 ChemSpider 38839 Wikidata Q4778002
properties
Molar mass	279.3 g mol −1
Physical state	firmly
density	1.2 g cm −3
Melting point	69-73 ° C
boiling point	295.9 ° C
solubility	heavy in water (8.4 g l −1 at 20 ° C)
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary Caution H and P phrases H: 302-317-412 P: 261-264-273-280-333 + 313-362 + 364
Toxicological data	566 mg kg −1 ( LD 50 ,  rat ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Metalaxyl is a chemical compound from the group of acetylalanines . Metalaxyl occurs as a racemic mixture of the ( R ) - and the ( S ) - enantiomer . ( R ) -Metalaxyl is the more potent compound (the eutomer ) and is also known as metalaxyl-M or mefenoxam .

history

Metalaxyl was launched in 1979 by Ciba-Geigy (now Syngenta ) and quickly became one of the most widely used fungicides under the brand names Ridomil and Subdue . In the meantime, however, some resistances have developed, such as B. in Phytophthora infestans . The effect is based on the inhibition of RNA synthesis in the ribosomes.

Extraction and presentation

Metalaxyl can be obtained by reacting 2,6-dimethylaniline (2,6-xylidine) with methyl 2-bromopropionate and methoxyacetyl chloride.

Stereochemistry

The metalaxyl racemate, i.e. the 1: 1 mixture of the ( S ) and ( R ) enantiomers , is of practical relevance :

Enantiomers of metalaxyl
CAS number: 69516-34-3	CAS number: 70630-17-0

Admission

Metalaxyl-M was approved as a fungicidal active ingredient in the European Union in 2002. The racemic mixture metalaxyl was not included in the list of permitted active ingredients in pesticides following a decision by the EU Commission in 2003 . Following a complaint by a manufacturer, the European Court of Justice overturned this decision in 2007. With effect from July 1, 2010, Metalaxyl was also approved for use as a fungicide in the European Union.

In Germany, plant protection products with the active ingredient Metalaxyl are approved and plant protection products with the active ingredient Metalaxyl-M in Germany, Austria and Switzerland.

Individual evidence

1. ^ Müfit Bahadir, Harun Parlar, Michael Spiteller: Springer Umweltlexikon . Springer DE, 2000, ISBN 3-642-56998-6 , pp. 757 ( limited preview in Google Book search).
2. ↑ ^{a b c d e f g} Entry on metalaxyl in the GESTIS substance database of the IFA , accessed on January 21, 2020(JavaScript required) .
3. ^ JH Montgomery (ed.): Agrochemicals Desk Reference. Environmental data . Lewis Publishers, Inc., Chelsea, Michigan 1993.
4. ↑ Entry on Methyl N- (2,6-dimethylphenyl) -N- (methoxyacetyl) -DL-alaninate in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can use the harmonized classification and expand labeling .
5. ↑ MEFENOXAM The Active Ingredient in Ridomil Gold
6. ↑ Ulrich Schirmer, Peter Jeschke, Matthias Witschel: Modern Crop Protection Compounds: Herbicides . John Wiley & Sons, 2012, ISBN 978-3-527-32965-6 , pp. 904 ( limited preview in Google Book search).
7. ↑ Thomas A. Unger: Pesticide Synthesis Handbook . William Andrew, 1996, ISBN 0-08-095716-1 , pp. 34 ( limited preview in Google Book search).
8. ↑ Directive 2002/64 / EC of the Commission of July 15, 2002 amending Directive 91/414 / EEC of the Council for the inclusion of the active substances Cinidon-ethyl, Cyhalofop-butyl, Famoxadone, Florasulam, Metalaxyl-M and Picolinafen (PDF)
9. ↑ Directive 2010/28 / EU of the Commission of April 23, 2010 amending Council Directive 91/414 / EEC to include the active substance metalaxyl (PDF)
10. ↑ General Directorate Health and Food Safety of the European Commission: Entry on Metalaxyl in the EU pesticide database; Entry in the national registers of plant protection products in Switzerland , Austria and Germany ; accessed on February 29, 2020.
11. ↑ General Directorate Health and Food Safety of the European Commission: Entry on Metalaxyl-M in the EU pesticide database; Entry in the national registers of plant protection products in Switzerland , Austria and Germany ; accessed on February 29, 2020.