Triclopyr

Triclopyr^[1]

Names
Preferred IUPAC name [(3,5,6-Trichloropyridin-2-yl)oxy]acetic acid
Other names 3,5,6-TPA; Trident (Agriphar)
Identifiers
CAS Number	55335-06-3^Y
3D model (JSmol)	Interactive image Interactive image
ChEBI	CHEBI:9682^N
ChemSpider	37801^N
ECHA InfoCard	100.054.161
PubChem CID	41428
UNII	MV06PHJ6I0^Y
CompTox Dashboard (EPA)	DTXSID0032497
InChI InChI=1S/C7H4Cl3NO3/c8-3-1-4(9)7(11-6(3)10)14-2-5(12)13/h1H,2H2,(H,12,13)^N Key: REEQLXCGVXDJSQ-UHFFFAOYSA-N^N InChI=1/C7H4Cl3NO3/c8-3-1-4(9)7(11-6(3)10)14-2-5(12)13/h1H,2H2,(H,12,13) Key: REEQLXCGVXDJSQ-UHFFFAOYAE
SMILES ClC1=C(OCC(O)=O)N=C(Cl)C(Cl)=C1 C1=C(C(=NC(=C1Cl)Cl)OCC(=O)O)Cl
Properties
Chemical formula	C7H4Cl3NO3
Molar mass	256.46 g·mol^−1
Appearance	Fluffy solid
Melting point	148 to 150 °C (298 to 302 °F; 421 to 423 K)
Solubility in water	440 mg/L
Solubility in acetone	989 g/kg
Acidity (pKa)	2.68
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is ^YN ?) Infobox references

Triclopyr (3,5,6-trichloro-2-pyridinyloxyacetic acid) is an organic compound in the pyridine group that is used as a systemic foliar herbicide^[2] and fungicide.^[3]

Uses

Triclopyr is a selective weedkiller used to control dicotyledonous weeds (i.e. broadleaf plants) while leaving monocotyledonous plants (mostly bulbs, grasses and conifers) unaffected,^[2] or to control rust fungus on soybean crops.^[3]

In the USA, it is sold under the trade names Garlon, Remedy, Turflon, Weed-B-Gon (purple label), Brush-B-Gon among others, and in the UK as SBK Brushwood Killer.

It is a major ingredient in Confront, which was withdrawn from most uses because of concerns about compost contamination from the other major ingredient, clopyralid.

Environmental effects

Triclopyr breaks down in soil with a half-life between 30 and 90 days. It degrades rapidly in water, and remains active in decaying vegetation for about 3 months.^[4]

The compound is slightly toxic to ducks (LD₅₀ = 1698 mg/kg) and quail (LD₅₀ = 3000 mg/kg).^[5] It has been found nontoxic to bees and marginally toxic to fish (rainbow trout LC₅₀ (96 hr) = 117 ppm).^[4]

Garlon's fact sheet for their triclopyr ester product indicates that triclopyr is highly toxic to fish, aquatic plants, and aquatic invertebrates, and should never be used in waterways, wetlands, or other sensitive habitats.^[6] This is only for the triclopyr ester product, not for the triclopyr amine product.

References

1. Merck Index, 11th Edition, 9572.
2. Appleby, Arnold P.; Müller, Franz; Carpy, Serge (2001). "Weed Control". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a28_165. ISBN 3-527-30673-0.
3. Shanmugasundaram, S.; Yeh, C.C.; Hartman, G.L.; Talekar, N.S. (1991). Vegetable Soybean Research Needs for Production and Quality Improvement (PDF). Taipei: Asian Vegetable Research and Development Center. pp. 86–87. ISBN 9789290580478. Retrieved 6 February 2016.
4. Environmental Fate Of Triclopyr, Carissa Ganapathy, Environmental Monitoring & Pest Management Branch Department of Pesticide Regulation Sacramento, CA (dead link 23 October 2023)
5. EXTOXNET (Extension Toxicology Network), Oregon State University
6. "Garlon XRT Herbicide" (PDF).

External links

• archived Triclopyr Technical Fact Sheet – National Pesticide Information Center
• Triclopyr General Fact Sheet – National Pesticide Information Center
• Triclopyr Pesticide Information Profile – Extension Toxicology Network
• Triclopyr in the Pesticide Properties DataBase (PPDB)