Dimethenamid, a herbicide

Dimethenamid, on its full name:  (RS)-2-Chloro-N-(2,4-dimethyl-3-thienyl)-N-(2-methoxy-1-methylethyl)acetamide, is a widely used herbicide. In 2001, about 7 million pounds of dimethenamid were used in the United States.  Dimethenamid is registered for control of annual grasses, certain annual broadleaf weeds and sedges in field corn, seed corn, popcorn and soybeans. Supplemental labeling also allows use on sweet corn, grain sorghum, dry beans and peanuts. In registering dimethinamide (SAN 582H/Frontier), EPA concluded that the primary means of dissipation of dimethenamid applied to the soil surface is photolysis, whereas below the surface loss was due largely to microbial metabolism. The herbicide was found to undergo anaerobic microbial degradation under denitrifying, iron-reducing, sulfate-reducing, or methanogenic conditions.  In that study, more than half of the herbicide carbon (based on 14C-labeling) added was found to be incorporated irreversibly into soil-bound residue.

Identifiers

• CAS number 87674-68-8 Yes
• PubChem 91744
• ChemSpider 82842 Yes
• KEGG C18499 Yes
• RTECS number AB5444200

Properties

• Molecular formula C12H18ClNO2S
• Molar mass 275.79 g/mol
• Appearance Tan to brown liquid
• Density 1.141 g/cm3

Hazards

• Flash point 151 °C
•  Moderate toxicant
• R-phrases R22
• Main hazards Xn (harmful)
• Possible carcinogene
• Moderate aquatic toxicity
• Toxic for algae
  
• Slightly toxic for some non-target terrestrial plans.