Butenachlor

Butenachlor
Names
Preferred IUPAC name
N-{[(2Z)-But-2-en-1-yloxy]methyl}-2-chloro-N-(2,6-diethylphenyl)acetamide
Other names
  • KH-218, KH 218, KH218
  • N-{[(2Z)-But-2-enyloxy]methyl}-2-chloro-2',6'-diethylacetanilide
  • (Z)-N-but-2-enyloxymethyl-2-chloro-2′,6′-diethylacetanilide
Identifiers
3D model (JSmol)
ChemSpider
UNII
  • InChI=1S/C17H24ClNO2/c1-4-7-11-21-13-19(16(20)12-18)17-14(5-2)9-8-10-15(17)6-3/h4,7-10H,5-6,11-13H2,1-3H3/b7-4-
    Key: InChIKey=HZDIJTXDRLNTIS-DAXSKMNVSA-N
  • N(COC/C=C\C)(C(CCl)=O)C1=C(CC)C=CC=C1CC
Properties
C17H24ClNO2
Molar mass 309.83 g·mol−1
Appearance Pale yellow liquid
Density 1.10 kg/L (11 lb/imp. gal)
Melting point 12.9 °C (55.2 °F; 286.0 K)
Boiling point 167 °C (333 °F; 440 K)
29 mg/L
Vapor pressure 0.93 mPa (0.02 mpsf)
Hazards
GHS labelling:
H302, H410
Lethal dose or concentration (LD, LC):
  • >2000 mg/kg (rat)
  • 1630 mg/kg
3.34 mg/L (rat, breathing)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Butenachlor is an obsolete selective chloroacetanilide, chloroacetamide herbicide used to control grasses and broadleaf weeds. It was introduced in 1976 and marketed as "Diphenox", by Agro-Kanesho.

Butenachlor's mode of action is to prevent formation of very long chain fatty acids; this makes its HRAC classification Group J (Australia), Group K3 (global) and Group 15 (numeric).

It is stable in acidic, neutral or weakly alkaline conditions; it is unstable in sublight.

Butenachlor is applied at 0.75-1.0 kg/Ha, and usually sold as a pesticide formulation as granules (GR).

Environmental behaviour

Butenachlor does not persist in soil; its soil half-life is 2 to 5 days. It is moderately toxic to fish, with a 96-hour LC50 of 0.48 mg/L (0.034 gr/imp. gal).

Safety

Butenachlor's acute oral LD50 on rats is 1630 mg/kg (male rats) and 1875 mg/kg (female rates). In mice, it is much less harmful, with an LD50 about 6300 mg/kg. It is slightly irritating to skin and eyes. The inhalatory LC50 for rats is 3.34 mg/L of air over 4 hours. A 90 day NOEL is 25 mg/kg/day for dogs. Butenachlor is non-teratogenic, and has no evident reproductive effects.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 Lewis, K.A., Tzilivakis, J., Warner, D. and Green, A. (2016) An international database for pesticide risk assessments and management. Human and Ecological Risk Assessment: An International Journal, 22(4), 1050-1064. DOI: 10.1080/10807039.2015.1133242
  2. ↑ "The WHO Guidelines to Classification of Pesticides by Hazard (Extremely Hazardous to Moderately Hazardous)". www.iloencyclopaedia.org. Retrieved 5 February 2026.
  3. ↑ "Butenachlor | Product Data Sheet | MedChemExpress". medchemexpress.com. Retrieved 5 February 2026.
  4. ↑ Rivard, Linda (2003) "Environmental Fate of Metolachlor", Environmental Monitoring Branch, Department of Pesticide Regulation, Sacramento, California, retrieved 5 February 2026
  5. ↑ "List of Herbicides Globally". www.weedscience.org.
  6. ↑ "Global Herbicide Classification Lookup". Herbicide Resistance Action Committee. Retrieved 5 February 2026.
  7. 1 2 3 4 Macbean, C. (2012). A World Compendium The Pesticide Manual (16th ed.). Hampshire, UK: British Crop Protection Council. p. 68. ISBN 978 1 901396 86 7.