Title: Pyriproxyfen
CAS Registry Number: 95737-68-1
CAS Name: 2-[1-Methyl-2-(4-phenoxyphenoxy)ethoxy]pyridine
Additional Names: 4-phenoxyphenyl (RS)-2-(2-pyridyloxy)propyl ether
Manufacturers' Codes: S-9318; S-31183
Trademarks: Sumilarv (Sumitomo)
Molecular Formula: C20H19NO3
Molecular Weight: 321.37
Percent Composition: C 74.75%, H 5.96%, N 4.36%, O 14.94%
Literature References: Juvenile hormone mimic. Prepn: S. Nishida et al., GB 2140010; eidem, US 4751225 (1984, 1988 both to Sumitomo). Ovicidal activity: K. R. S. Ascher, M. Eliyahu, Phytoparasitica 16, 15 (1988). Environmental persistence study: C. H. Schaefer et al., Ecotoxicol. Environ. Saf. 21, 207 (1991). Field trial to control tsetse flies: J. W. Hargrove, P. A. Langley, Bull. Entomol. Res. 83, 361 (1993).
Properties: Pale yellow liquid. nD20.5 1.5823. Solidifies upon standing to give crystals, mp 49.7°.
Melting point: mp 49.7°
Index of refraction: nD20.5 1.5823
Use: Insecticide.
Therap-Cat-Vet: Ectoparasiticide.
Pyrisuccideanol Pyrithiamine Pyrithiobac Pyrithione Pyrithyldione

Chemical structure of pyriproxyfen
CAS number 95737-68-1 YesY
PubChem 91753
ChemSpider 82851 YesY
KEGG C18605 YesY
ChEBI CHEBI:39260 YesY
ATCvet code QP53AX23
Jmol-3D images Image 1
Molecular formula C20H19NO3
Molar mass 321.369 g/mol
Density 1.2 g/cm³
Melting point 46 °C
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Pyriproxyfen is a pyridine-based pesticide which is found to be effective against a variety of arthropoda.[1] It was introduced to the US in 1996, to protect cotton crops against whitefly. It has also been found useful for protecting other crops. It is also used as a prevention for fleas on household pets.

Pyriproxyfen is a juvenile hormone analog, preventing larvae from developing into adulthood and thus rendering them unable to reproduce.

In the US pyriproxyfen is often marketed under the trade name Nylar. In Europe pyriproxyfen is known under the brand names Cyclio (Virbac) and Exil Flea Free TwinSpot (Emax).