NOMENCLATURE

Common name dichlormid (WSSA)

IUPAC name N,N-diallyl-2,2-dichloroacetamide 

Chemical Abstracts name 2,2-dichloro-N,N-di-2-propenylacetamide 

CAS RN [37764-25-3]  Development codes R-25788 (Stauffer) 

PHYSICAL CHEMISTRY

Composition Tech. grade is c. 95% pure.  Mol. wt. 208.1  M.f. C₈H₁₁Cl₂NO  Form Clear viscous liquid; (tech., amber-to-brown).  M.p. 5.0-6.5 ºC (tech.)  B.p. 130 °C/10 mmHg  V.p. 800 mPa (25 ºC)  K_OW logP = 1.84?.03 (25 ºC)  S.g./density 1.202 (20 ºC); (tech., 1.192-1.204)  Solubility In water c. 5 g/l. In kerosene c. 15 g/l. Miscible with acetone, ethanol, and xylene.  Stability Unstable above 100 ºC. Decomposes violently if heated with iron. Stable to light. 

COMMERCIALISATION

History Its use to enhance herbicidal selectivity reported by F. Y. Chang et al. (Can. J. Plant Sci., 1972, 52, 707). G. R. Stephenson (J. Agric. Food Chem., 1978, 26, 137) compared the chemical structure/biological activity of analogues. Introduced by the Stauffer Chemical Co. (now Syngenta AG).  Patents US 4137070 

APPLICATIONS

Mode of action See R. E. Wilkinson (Chemistry and Mode of Action of Herbicide Antidotes, p. 85); uptake by plant roots studied (R. A. Gray & G. K. Joo, ibid., p. 67).  Uses Increases the tolerance of maize to thiocarbamate herbicides.  Formulation types CG; CS; EC; GR; Liquid. 

ANALYSIS

Product and residue analysis by capillary glc, details available from Syngenta.

MAMMALIAN TOXICOLOGY

Oral Acute oral LD₅₀ for male rats 2816, female rats 2146 mg/kg.  Skin and eye Acute percutaneous LD₅₀ for rabbits >5000, rats >2000 mg/kg. Mild skin irritant; slightly irritating to eyes (rabbits). Mild skin sensitiser (guinea pigs).  Inhalation LC₅₀ (1 h) for rats >5.5 mg/l air.  NOEL (2 y) for rats 7 mg/kg diet.  Toxicity class WHO (a.i.) III  EC hazard (Xi; R38) 

ECOTOXICOLOGY

Birds Dietary LC₅₀ (5 d) for mallard ducks 14 500, bobwhite quail >10 000 mg/kg diet.  Fish LC₅₀ (96 h) for rainbow trout 141 mg/l.  Daphnia LC₅₀ (48 h) 161 mg/l. 

ENVIRONMENTAL FATE

Animals For metabolism in rats, see J. B. Miallis et al., Chemistry and Mode of Action of Herbicide Antidotes, p. 109.  Plants For metabolism in maize, see idem, ibid.  Soil/Environment In soil, DT₅₀ c. 8 d (27-29 ºC). For degradation in soil, see idem, ibid.