Dimethenamid-P

Structural formula
Simplified structural formula without taking stereoisomerism into account
General
Surname	Dimethenamid-P
other names	( S ) -2-chloro- N - (2,4-dimethyl-3-thienyl) - N - (2-methoxy-1-methylethyl) acetamide Frontier
Molecular formula	C 12 H 18 ClNO 2 S
Brief description	brownish liquid with a slightly aromatic odor
External identifiers / databases
CAS number 163515-14-8 EC number 605-329-9 ECHA InfoCard 100.129.702 PubChem 13633097 Wikidata Q27157042
properties
Molar mass	275.79 g mol −1
Physical state	liquid
density	1.19 g cm −3
Melting point	<−50 ° C
boiling point	> 280 ° C
solubility	little in water (1.45 g l −1 at 25 ° C)
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary Caution H and P phrases H: 302-317-410 P: 261-311
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Dimethenamid-P is a pesticide from the group of chloroacetamides. It is used as a herbicide in Europe, especially in maize and beet , but also in legumes (soybeans) and sunflower cultivation.

Dimethenamid-P consists of the two more effective stereoisomers of Dimethenamid , which is used as a mixture of four isomers.

Extraction and presentation

Dimethenamid can be produced by a multistage reaction from 2-mercaptopropionic acid , methacrylic acid , 1-methoxy-2-propylamine , thionyl chloride and chloroacetic acid chloride . Methacrylic acid and 2-mercaptopropionic acid react with one another and cyclize to 2,4-dimethyl-tetrahydro-3-thiophenone.

Isomerism

Dimethenamid consists - similar to the related chloroacetamides alachlor and metolachlor - of four stereoisomers because it

• axial chirality along the bond (limited rotatability) between the 3-position of the thiophene ring and the nitrogen atom and
• a stereogenic center in the side chain

owns. The following stereoisomers thus exist: (1 S , a S ) form, (1 R , a R ) form, (1 S , a R ) form and the (1 R , a S ) form.

Dimethenamid-P is the mixture of the (1 S , a S ) -form and the (1 S , a R ) -form - sometimes also called "( S ) -Dimethenamid" - and is more effective as a herbicide and can be dosed lower than the mixture of all four stereoisomers.

use

Estimated application rate of Dimethenamid-P in 2011 in the USA

Admission

In 2003, Dimethenamid-P was added to the list of permitted active ingredients in plant protection products in accordance with Directive 91/414 / EEC. Dimethenamid-P is approved in Germany, Austria and Switzerland, among others.

Individual evidence

1. ↑ ^{a b c d e f} Entry on Dimethenamid-P in the GESTIS substance database of the IFA , accessed on May 26, 2018(JavaScript required) .
2. ↑ Entry on Dimethenamid-P in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on May 27, 2018. Manufacturers or distributors can expand the harmonized classification and labeling .
3. ↑ Data sheet Dimethenamide-P from Sigma-Aldrich , accessed on May 28, 2018 ( PDF ).
4. ↑ Thomas A. Unger: Pesticide Synthesis Handbook . William Andrew, 1996, ISBN 0-8155-1853-6 , pp. 740 .
5. ↑ ^{a b} patent application US5457085 : Optical isomer of dimethenamid. Registered on September 21, 1994 , published October 10, 1995 , applicant: Sandoz , inventor: Stefan Blarer, Reynold Chollet, Karl Seckinger, Thomas Vettiger. ‌
6. ↑ Commission Directive 2003/84 / EC of September 25, 2003 (PDF) amending Council Directive 91/414 / EEC to include the active substances Flurtamone, Flufenacet, Iodosulfuron, Dimethenamid-p, Picoxystrobin, Fosthiazate and Silthiofam.
7. ↑ General Directorate Health and Food Safety of the European Commission: Entry on Dimethenamid-P in the EU pesticide database; Entry in the national registers of plant protection products in Switzerland , Austria and Germany ; Retrieved February 19, 2016.