Title: Dimethenamid
CAS Registry Number: 87674-68-8
CAS Name: 2-Chloro-N-(2,4-dimethyl-3-thienyl)-N-(2-methoxy-1-methylethyl)acetamide
Manufacturers' Codes: SAN-582H
Trademarks: Frontier (BASF); Guardsman (BASF)
Molecular Formula: C12H18ClNO2S
Molecular Weight: 275.79
Percent Composition: C 52.26%, H 6.58%, Cl 12.86%, N 5.08%, O 11.60%, S 11.63%
Literature References: Preemergence herbicide for use in food crops. Prepn: K. Seckinger et al., GB 2114566; eidem, US 4666502 (1983, 1987 both to Sandoz). Bioactivity of stereoisomers: M. Couderchet et al., Pestic. Sci. 50, 221 (1997). Comprehensive description: J. Harr et al., Proc. Br. Crop Prot. Conf. - Weeds 1991, 87-92. Review of field trials and persistence in soil: A. Rahman, T. K. James, Proc. 45th N. Z. Plant Prot. Conf. 1992, 84-88.
Properties: Yellowish-brown, viscous liquid. Odorless to weak tar-like odor. Mixture of 4 stereoisomers (1RS,aRS). bp26.7 Pa 127°. Vapor pressure (25°): 36.7 mPa. d25 1.187. Soly (25°): water 1174 mg/l; heptane 28.2 g/100 g; isooctane 22.0 g/100 g; ether, kerosene, ethanol >50%. LD50 in rats (mg/kg): 1570 orally; >2000 dermally; LC50 in bluegill sunfish, rainbow trout (mg/l): 6.4, 2.6 (Harr).
Boiling point: bp26.7 Pa 127°
Density: d25 1.187
Toxicity data: LD50 in rats (mg/kg): 1570 orally; >2000 dermally; LC50 in bluegill sunfish, rainbow trout (mg/l): 6.4, 2.6 (Harr)
Derivative Type: Dimethenamid P
CAS Registry Number: 163515-14-8
Additional Names: DMTA-P
Manufacturers' Codes: BAS-656H
Trademarks: Outlook (BASF)
Literature References: Consists of the 1S,aRS isomers. Prepn: K. Seckinger et al., US 5457085 (1995 to Sandoz). Review of properties and activity: T. Guillet et al., Phytoma 546, 50-53 (2002).
Properties: Faintly yellow viscous liquid. [a]D23 +3.5° (c = 1.102 in CH3OH). bp9.3 Pa 122.6°. d20 1.195. Vapor pressure (25°): 2.5 ´ 10-3 Pa. Soly in water (25°): 1449 mg/l. LD50 in rats (mg/kg): 429 orally; >2000 dermally. LC50 (96 hr) in rainbow trout (mg/l): 6.3 (Guillet).
Boiling point: bp9.3 Pa 122.6°
Optical Rotation: [a]D23 +3.5° (c = 1.102 in CH3OH)
Density: d20 1.195
Toxicity data: LD50 in rats (mg/kg): 429 orally; >2000 dermally; LC50 (96 hr) in rainbow trout (mg/l): 6.3 (Guillet)
Use: Herbicide.
Dimethicone Dimethindene Dimethirimol Dimethisoquin Dimethoate

CAS number 87674-68-8 YesY
PubChem 91744
ChemSpider 82842 YesY
KEGG C18499 YesY
RTECS number AB5444200
Jmol-3D images Image 1
Image 2
Molecular formula C12H18ClNO2S
Molar mass 275.79 g/mol
Appearance Tan to brown liquid
Density 1.141 g/cm3
R-phrases R22
Main hazards Xn (harmful)
Flash point 151 °C; 304 °F; 424 K
 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

Dimethenamid is a widely used herbicide. In 2001, about 7 million pounds of dimethenamid were used in the United States.[4] 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.[5] 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.