3352. Diquat Dibromide

Nomenclature

CAS number: 85-00-7
6,7-Dihydrodipyrido[1,2-a:2′,1′-c]pyrazinediium dibromide; 1,1′-ethylene-2,2′-dipyridylium dibromide; FB/2; Reglone (Syngenta).
C12H12Br2N2; mol wt 344.05.
C 41.89%, H 3.52%, Br 46.45%, N 8.14%.

Description and references

Prepn: Fielden et al., US 2823987 (1958 to ICI). Herbicidal properties: Brian et al., Nature 181, 446 (1958). Environmental fate and toxicity: Simsiman et al., Residue Rev. 62, 131-174 (1976). Acute toxicity study: T. B. Gaines, R. E. Linder, Fundam. Appl. Toxicol. 7, 299 (1986). Review: Akhavein, Linscott, ibid. 23, 97-145 (1968).

Chemical structure

Derivative

Monohydrate.

Nomenclature

CAS number: 6385-62-2

Properties

Pale yellow crystals from water, mp <320° (dec). Also reported as mp 335-340°. uv max: 308.31 nm (ε 18000). Soly in water at 20°: 70%. Insoluble in organic solvents. Slightly sol in alcohol. Stable in acid or neutral soln. LD50 in male, female rats (mg/kg): 147, 121 orally; in male rats (mg/kg): 433 dermally (Gaines, Linder).

Caution

Potential symptoms of overexposure are irritation of eyes, skin, mucous membranes, respiratory system; rhinorrhea, epistaxis; skin burns; nausea, vomiting, diarrhea, malaise; kidney and liver injury; cough, chest pain, dyspnea, pulmonary edema; tremor, convulsions; delayed wound healing. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 122.

Use

Contact herbicide used also to produce desiccation and defoliation.