3214. Dimethenamid

Nomenclature

CAS number: 87674-68-8
2-Chloro-N-(2,4-dimethyl-3-thienyl)-N-(2-methoxy-1-methylethyl)acetamide; SAN-582H; Frontier (BASF); Guardsman (BASF).
C12H18ClNO2S; mol wt 275.79.
C 52.26%, H 6.58%, Cl 12.86%, N 5.08%, O 11.60%, S 11.63%.

Description and 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.

Chemical structure

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).

Derivative

Dimethenamid P.

Nomenclature

CAS number: 163515-14-8
DMTA-P; BAS-656H; Outlook (BASF).

Description and 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. [α]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).

Use

Herbicide.