Fenoprop

Fenoprop, also called 2,4,5-TP, is the organic compound 2-(2,4,5-trichlorophenoxy)propionic acid.^[2] It is a phenoxy herbicide and a plant growth regulator, an analog of 2,4,5-T in which the latter's acetic acid sidechain is replaced with a propionate group (with an extra CH₃). The addition of this extra methyl group creates a chiral centre in the molecule and useful biological activity is found only in the (2R)-isomer.^[3] The compound's mechanism of action is to mimic the auxin growth hormone indoleacetic acid (IAA).^[4] When sprayed on plants it induces rapid, uncontrolled growth. As with 2,4,5-T, fenoprop is toxic to shrubs and trees.

Fenoprop

Names
Preferred IUPAC name rac-(2R)-2-(2,4,5-trichlorophenoxy)propanoic acid
Other names 2-(2,4,5-Trichlorophenoxy)propionic acid Silvex
Identifiers
CAS Number	93-72-1 Y
3D model (JSmol)	Interactive image
Abbreviations	2,4,5-TP
ChEBI	CHEBI:34758
ChEMBL	ChEMBL460296 Y
ChemSpider	6891 Y
ECHA InfoCard	100.002.066
KEGG	C14532 Y
PubChem CID	7158
UNII	D2HZL58IS3
CompTox Dashboard (EPA)	DTXSID0021387
InChI InChI=1S/C9H7Cl3O3/c1-4(9(13)14)15-8-3-6(11)5(10)2-7(8)12/h2-4H,1H3,(H,13,14) Y Key: ZLSWBLPERHFHIS-UHFFFAOYSA-N Y InChI=1/C9H7Cl3O3/c1-4(9(13)14)15-8-3-6(11)5(10)2-7(8)12/h2-4H,1H3,(H,13,14) Key: ZLSWBLPERHFHIS-UHFFFAOYAC
SMILES Clc1cc(OC(C(=O)O)C)c(Cl)cc1Cl
Properties[1]
Chemical formula	C9H7Cl3O3
Molar mass	269.51
Appearance	White powder
Density	1.21 g/cm3 at 20 °C
Melting point	180 °C (356 °F; 453 K)
log P	3.8 (20 °C)
Acidity (pKa)	2.84
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

The name Silvex was used in the USA but it has been banned from use there since 1985. According to the Environmental Protection Agency its greatest use was as a postemergence herbicide for control of woody plants, and broadleaf herbaceous weeds in rice and bluegrass turf, in sugarcane, in rangeland improvement programs and on lawns.^[5] Fenoprop and some of its esters were in use from 1945 but are now obsolete.^[1]

See also

• Phenoxy herbicides
• 2,4,5-Trichlorophenoxyacetic acid

References

1. Pesticide Properties Database. "Fenoprop". University of Hertfordshire. Retrieved 2021-03-11.
2. "Compendium of Pesticide Common Names". alanwood.net.
3. Wendeborn, S.; Smits, H. (31 December 2012). "Synthetic Auxins". In Erick M. Carreira; Hisashi Yamamoto (eds.). Comprehensive Chirality. ISBN 9780080951683.
4. Grossmann, K. (2010). "Auxin herbicides: current status of mechanism and mode of action". Pest Management Science. 66 (2): 2033–2043. doi:10.1002/ps.1860. PMID 19823992.
5. US Environmental Protection Agency. "Consumer Factsheet on: 2,4,5-TP (SILVEX)" (PDF). Retrieved 2021-03-11.