Etoxazole

Etoxazole is a narrow spectrum systemic acaricide used to combat spider mites. It targets a variety of mites in the egg, larvae and nymph stages however not the adult stage. It also exhibits insecticidal activity towards aphids, the green rice leafhopper and diamondback moth. The mode of action has been shown to inhibit chitin synthase (IRAC group 10B).^[2] Resistance due to its high efficacy and cross resistance when used with other acaricides are both of concern similar to was seen in the fast development of cross resistance in the previous generation of acaricides. The LC₅₀ for resistant mite strains has been observed over 100,000 times greater than that of susceptible strains. Thus resistance management strategies are important in order to limit the increase of etoxazole resistant mite strains.^[3][4]

Etoxazole

Names
IUPAC name 2-(2,6-Difluorophenyl)-4-[2-ethoxy-4-(2-methyl-2-propanyl)phenyl]-4,5-dihydro-1,3-oxazole
Other names (R,S)-5-tert-butyl-2-[2,6-difluorophenyl)-4,5-dihydro-1,3-oxazol-4-yl]phenetole [1]
Identifiers
CAS Number	153233-91-1
3D model (JSmol)	Interactive image
Beilstein Reference	8930214
ChEBI	CHEBI:39329
ChEMBL	ChEMBL1881674
ChemSpider	135707
ECHA InfoCard	100.107.983
EC Number	604-891-2
KEGG	C18495
PubChem CID	153974
UNII	LBE5H21G6L
CompTox Dashboard (EPA)	DTXSID8034586
InChI InChI=1S/C21H23F2NO2/c1-5-25-18-11-13(21(2,3)4)9-10-14(18)17-12-26-20(24-17)19-15(22)7-6-8-16(19)23/h6-11,17H,5,12H2,1-4H3 Key: IXSZQYVWNJNRAL-UHFFFAOYSA-N
SMILES CCOc1cc(ccc1C2COC(=N2)c3c(cccc3F)F)C(C)(C)C
Properties
Chemical formula	C21H23F2NO2
Molar mass	359.417 g·mol−1
Appearance	colorless crystalline powder with a musty odor [1]
Density	1.238 [1]
Melting point	101.5–102.5°C [1]
Solubility in water	insoluble in H2O, slightly soluble in hexane, n-heptane, soluble in MeOH, EtOH, acetone, cyclohexanone, THF, MeCN, EtOAc, xylene.[1]
log P	Kow 5.59 [1]
Vapor pressure	7 mPa @ 25°C [1]
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H410
Precautionary statements	P273, P391, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Etoxazole has a mammalian toxicity LD₅₀ of 5 g/kg and an environmental persistence DT₅₀ of 19 days.^[5] Toxicity towards fish is of potential concern.

Etoxazole was discovered in the 1980s by Yashima and was released for commercial use in 1998 in Japan. It is sold under various commercial preparations for crop application such as TetraSan 5 WDG^[6] and Zeal by Valent in the United States.

Stereoisomerism

Etoxazole (2 stereoisomers)
(S)-configuration	(R)-configuration