Beflubutamide

Structural formula
Structural formula without stereochemistry
General
Surname	Beflubutamide
other names	( RS ) - N -Benzyl-2- (4-fluoro-3-trifluoromethylphenoxy) butanamide (±) - N -Benzyl-2- (4-fluoro-3-trifluoromethylphenoxy) butanamide
Molecular formula	C 18 H 17 F 4 NO 2
External identifiers / databases
CAS number 113614-08-7 (racemate) 113614-09-8 ( S ) -flubutamide 1402164-94-6 ( R ) -flubutamide EC number 601-267-1 ECHA InfoCard 100.129.750 PubChem 6451159 ChemSpider 4953638 Wikidata Q22712766
properties
Molar mass	355.33 g mol −1
Melting point	75 ° C
solubility	3.29 mg l −1 (in water ) 2.18 g l −1 (in n -heptane ) 473 g l −1 (in methanol ) 600 g l −1 (in acetone )
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary Caution H and P phrases H: 410 P: 273-501
Toxicological data	> 5000 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 .

Beflubutamide is a chemical compound from the group of carboxamides . It is used as a herbicide in agriculture .

use

Beflubutamide is used in arable farming , in the cultivation of winter soft wheat , winter barley , winter triticale and winter rye . These crops should be protected from annual, dicotyledon weeds .

Stereochemistry

Generally speaking, chemical compounds with at least one stereocenter form up to 2 ⁿ stereoisomers . Here n is the number of stereocenters. Beflubutamide has a stereocenter and accordingly forms two enantiomers . The racemate is used , i.e. the 1: 1 mixture of the ( S ) and ( R ) form:

Enantiomers of beflubutamide
( S ) -flubutamide	( R ) -flubutamide

effect

The mode of action of beflubutamide is assigned to HRAC group F1. The herbicides of the HRAC group F1 influence the biosynthesis of carotenoids in the target organisms . The molecular characteristic of this group is the tetrafluorocarbon-phenyl partial structure.

Carotenoids play an important role in photosynthesis . They serve as accessory pigments . In the absence of these pigments, the light-harvesting complexes in the chloroplasts , the site of photosynthesis, are no longer effectively able to absorb different wavelengths , causing photosynthesis to decrease. In addition to the function of light absorption, the carotenoids in fruits and flowers also serve as colorants . Furthermore, carotenoids have the property of counteracting the photoinduced formation of reactive oxygen species . In this way, carotenoids protect the chlorophyll , which is responsible for the green color of leaves , from photooxidative destruction.

Beflubutamide inhibits the enzyme phytoene desaturase (PDS) in carotenoid biosynthesis . PDS catalyzes the dehydrogenation of phytoene in the biosynthesis , which is necessary so that the final carotenoid synthesis can take place in further reaction steps.

In the presence of flubutamide, plants can no longer produce the vital carotenoids. This leads to the death of the organism. Due to the absence of carotenoids, more reactive oxygen compounds occur, which ensure that the chlorophylls in the plant are oxidized and the green color decreases. This is why herbicides that inhibit carotenoid synthesis are also known as bleach herbicides.

Admission

Beflubutamide has been approved in the EU since December 1, 2007.

Trade names

• BeFlex ^®

Individual evidence

1. ↑ ^{a b c d e f g} Entry on beflubutamide in the Pesticide Properties DataBase (PPDB) of the University of Hertfordshire , accessed on February 6, 2018.
2. ↑ Entry on beflubutamide in the GESTIS substance database of the IFA , accessed on February 7, 2018(JavaScript required) .
3. ↑ Entry on beflubutamide in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 15, 2018. Manufacturers or distributors can expand the harmonized classification and labeling .
4. ↑ Data sheet Beflubutamid from Sigma-Aldrich , accessed on February 13, 2018 ( PDF ).
5. ↑ List of approved plant protection products from the Federal Office for Consumer Protection and Food Safety . Entry on befubutamide. Last accessed on February 7, 2018.
6. ↑ Paula Y. Bruice: Organic Chemistry: Study compact . Pearson Studium, Munich 2011, ISBN 978-3-86894-102-9 , p. 205.
7. ↑ Ignaz J. Buerge, Markus D. Müller, Thomas Poiger: The Chiral Herbicide Beflubutamid (II): Enantioselective Degradation and Enantiomerization in Soil, and Formation / Degradation of Chiral Metabolites . In: Environmental Science Technology. American Chemical Society 2013, DOI: 10.1021 / es301877n , pp. 6812-6818.
8. ↑ General Directorate Health and Food Safety of the European Commission: Entry on Beflubutamide in the EU pesticide database ; Entry in the national list of plant protection products in Germany ; Retrieved February 6, 2018. Review report for the active substance Beflubutamid. P. 7.
9. ↑ ^{a b c} Thomas Seitz, Michael G. Hoffmann, Hansjörg Krähmer: Herbicides for agriculture: chemical weed control . In: Chemistry in our time, WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 2013, DOI: 10.1002 / ciuz.200300279 , pp. 112–126.
10. ↑ Hans-Walter Heldt, Birgit Piechulla: Plant biochemistry . Springer-Verlag Berlin Heidelberg, 2015, DOI: 10.1007 / 978-3-662-44398-9 , pp. 54-60.
11. ^ ^{A b} Hans-Walter Heldt, Birgit Piechulla: Plant biochemistry . Springer-Verlag Berlin Heidelberg, 2015, DOI: 10.1007 / 978-3-662-44398-9 , pp. 407-411.
12. ↑ Implementing Regulation (EU) No. 540/2011 of the Commission of May 25, 2011 for the implementation of Regulation (EC) No. 1107/2009 of the European Parliament and of the Council with regard to the list of approved active substances , accessed on February 7, 2018 , p. 64.