Etoxazole

Structural formula
	Basic structural formula (stereocenter is marked with an * )
General
Surname	Etoxazole
other names	(±) -2- (2,6-Difluorophenyl) -4- [2-ethoxy-4- (2-methyl-2-propanyl) phenyl] -4,5-dihydro-1,3-oxazole ( IUPAC ) ; ( RS ) -5- tert -Butyl-2- [2- (2,6-difluorophenyl) -4,5-dihydro-1,3-oxazol-4-yl] phenetole; TetraSan; Yimanzuo;
Molecular formula	C 21 H 23 F 2 NO 2
Brief description	White dust
External identifiers / databases
EC number	604-891-2
ECHA InfoCard	100.107.983
PubChem	153974
ChemSpider	135707
Wikidata	Q1371651
properties
Molar mass	359.41 g mol −1
Physical state	firmly
density	1.24 g cm −3
Melting point	101-102 ° C
solubility	almost insoluble in water; soluble in methanol, acetone and xylene;
safety instructions
GHS hazard labeling from Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary Caution
H and P phrases	H: 410
	P: 261-273-304 + 340 + 312-391-501
Toxicological data	> 5000 mg kg −1 ( LD 50 , rat , oral ) ; > 200 mg kg −1 ( LD 50 , rabbit , transdermal ) ;
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Etoxazole is a racemic chemical compound belonging to the group of the diaryl-1,3-oxazolines.

Stereoisomerism

It is a racemate (1: 1 mixture) of the ( R ) - and ( S ) form, which can be named as follows:

( R ) -5- tert -Butyl-2- [2- (2,6-difluorophenyl) -4,5-dihydro-1,3-oxazol-4-yl] phenetole
( S ) -5- tert -Butyl-2- [2- (2,6-difluorophenyl) -4,5-dihydro-1,3-oxazol-4-yl] phenetole

The ( S ) -form degrades faster than the ( R ) -form in the soil .

Etoxazole (Two Stereoisomers)
( S ) configuration	( R ) configuration

Extraction and presentation

Etoxazole can be obtained as an intermediate product by a multi-stage reaction, starting from 2-ethoxy-4- tert- butyl-acetophenone, by converting it into the oxime and the amino alcohol. This is reacted with 2,6-difluorobenzoyl chloride , followed by a base-catalyzed cyclization, to give etoxazole.

A variant of this synthesis route starts with a carboxylic acid ester . Acylation, reduction and cyclization give etoxazole.

Ethoxazole has a center of chirality on the dehydro- oxazole ring, but the synthesis always results in the racemate and not an enantiomerically pure product.

properties

Etoxazole is a white solid that is insoluble in water.

use

Etoxazole is used as an active ingredient in crop protection products. It was launched as an acaricide in 1998 by the Japanese company Yashima and was later marketed by Sumitomo.

Admission

Etoxazole has been approved for use as an acaricide in Europe since 2005.

No pesticides containing this active ingredient are permitted in Germany, but in Switzerland and Austria.

Individual evidence

↑ EU: Review report for the active substance etoxazole (PDF; 240 kB), November 29, 2004.
↑ ^a ^b ^c ^d ^e ^f Datasheet Etoxazole from Sigma-Aldrich , accessed on May 20, 2017 ( PDF ).
↑ ^a ^b ^c EPA: Petition for Etoxazole (PDF; 4.1 MB)
↑ ^a ^b Entry for CAS no. 153233-91-1 in the GESTIS substance database of the IFA , accessed on November 1, 2012(JavaScript required) .
↑ Entry on (RS) -5-tert-butyl-2- [2- (2,6-difluorophenyl) -4,5-dihydro-1,3-oxazol-4-yl] phenetols Template: Linktext-Check / Escaped in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on August 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ D. Sun, J. Pang, Q. Fang, Z. Zhou, B. Jiao: Stereoselective toxicity of etoxazole to MCF-7 cells and its dissipation behavior in citrus an soil , in: SpringerLink , 2016 , (23), p 24731-24738; doi : 10.1007 / s11356-016-7393-7 .
↑ ^a ^b ^c Wolfgang Krämer, Ulrich Schirmer, Peter Jeschke, Matthias Witschel: Modern Crop Protection Compounds . John Wiley & Sons, 2012, ISBN 978-3-527-32965-6 , pp. 1024 ( limited preview in Google Book Search).
↑ Directive 2005/34 / EC of the Commission of May 17, 2005 amending Council Directive 91/414 / EEC to include the active substances Etoxazole and Tepraloxydim (PDF)
^ Directorate-General for Health and Food Safety of the European Commission: Entry on Etoxazole in the EU pesticide database; Entry in the national registers of plant protection products in Switzerland , Austria and Germany ; accessed on December 8, 2019.

[EU-1] EU: Review report for the active substance etoxazole (PDF; 240 kB), November 29, 2004.

[Sigma-2] ↑ ^a ^b ^c ^d ^e ^f Datasheet Etoxazole from Sigma-Aldrich , accessed on May 20, 2017 ( PDF ).

[EPA-3] EPA: Petition for Etoxazole (PDF; 4.1 MB)

[GESTIS-4] Entry for CAS no. 153233-91-1 in the GESTIS substance database of the IFA , accessed on November 1, 2012(JavaScript required) .

[CLP_100.107.983-5] Entry on (RS) -5-tert-butyl-2- [2- (2,6-difluorophenyl) -4,5-dihydro-1,3-oxazol-4-yl] phenetols Template: Linktext-Check / Escaped in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on August 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[6] D. Sun, J. Pang, Q. Fang, Z. Zhou, B. Jiao: Stereoselective toxicity of etoxazole to MCF-7 cells and its dissipation behavior in citrus an soil , in: SpringerLink , 2016 , (23), p 24731-24738; doi : 10.1007 / s11356-016-7393-7 .

[Wolfgang_Krämer,_Ulrich_Schirmer,_Peter_Jeschke,_Matthias_Witschel-7] Wolfgang Krämer, Ulrich Schirmer, Peter Jeschke, Matthias Witschel: Modern Crop Protection Compounds . John Wiley & Sons, 2012, ISBN 978-3-527-32965-6 , pp. 1024 ( limited preview in Google Book Search).

[8] Directive 2005/34 / EC of the Commission of May 17, 2005 amending Council Directive 91/414 / EEC to include the active substances Etoxazole and Tepraloxydim (PDF)

[PSM-9] Directorate-General for Health and Food Safety of the European Commission: Entry on Etoxazole in the EU pesticide database; Entry in the national registers of plant protection products in Switzerland , Austria and Germany ; accessed on December 8, 2019.