2127. o-Chlorobenzylidenemalononitrile

Nomenclature

CAS number: 2698-41-1
[(2-Chlorophenyl)methylene]propanedinitrile; o-chlorobenzalmalononitrile; β,β-dicyano-o-chlorostyrene; CS.
C10H5ClN2; mol wt 188.61.
C 63.68%, H 2.67%, Cl 18.80%, N 14.85%.

Description and references

Lacrimatory chemical warfare agent. Prepn: B.B. Corson, R. W. Stoughton, J. Am. Chem. Soc. 50, 2825 (1928). Pharmacology: R. W. Brimblecombe et al., Br. J. Pharmacol. 44, 561 (1972). Toxicology: C. L. Punte et al., Toxicol. Appl. Pharmacol. 4, 656 (1962); J. R. Gaskins et al., Arch. Environ. Health 24, 449 (1972); B. Ballantyne, S. Callaway, Med. Sci. Law 12, 43 (1972). Comparative toxicity of CS and ω-chloroacetophenone, q.v.: B. Ballantyne, D. W. Swanston, Arch. Toxicol. 40, 75 (1978).

Chemical structure

Properties

White crystalline solid, mp 95-96°, bp 310-315°. Vapor pressure at 20°: 3.4 × 10-5 mm Hg. Sparingly sol in water; sol in acetone, dioxane, methylene chloride, ethyl acetate, benzene. LD50 in rats (mg/kg): 28 i.v., 48 i.p.; LC50 in rats: 88,480 mg/min/m3 (Ballantyne, Swanston).

Caution

Potential symptoms of overexposure are pain, burning of eyes, lacrimation and conjunctivitis; erythemic eyelids, blepharospasm; irritation of throat, coughing and chest constriction; headache; erythema and vesiculation of skin. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 62.

Use

Riot control agent.