3574. Endosulfan

Nomenclature

CAS number: 115-29-7
6,7,8,9,10,10-Hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin 3-oxide; 1,4,5,6,7,7-hexachloro-5-norbornene-2,3-dimethanol cyclic sulfite; 1,2,3,4,7,7-hexachlorobicyclo[2.2.1]-2-heptene-5,6-bisoxymethylene sulfite; chlorthiepin; Malix (Bayer CropSci.); Thiodan (Bayer CropSci.); Thionex (Makhteshim-Agan).
C9H6Cl6O3S; mol wt 406.93.
C 26.56%, H 1.49%, Cl 52.27%, O 11.80%, S 7.88%.

Description and references

Prepd by reaction of hexachlorocyclopentadiene with cis-butene-1,4-diol to form the bicyclic dialcohol, followed by esterification and cyclization with SOCl2: Geering, Nelson, US 2983732 (1961 to Hooker). Configuration studies: Reimschneider, Wuscherpfenning, Z. Naturforsch. 17b, 585 (1962); Forman et al., J. Org. Chem. 30, 169 (1965). Toxicity study: T. B. Gaines, Toxicol. Appl. Pharmacol. 14, 515 (1969). Review of toxicology and human exposure: Toxicological Profile for Endosulfan (PB2000-108023, 2000) 323 pp.

Chemical structure

Properties

Commercial product brown crystals. mp 70-100° (pure mp 106°). Practically insol in water. Sol in most organic solvents. Stable toward dil mineral acids; hydrolyzed rapidly by alkalies. Commercial product is a mixture of α-isomer, mp 108-110°, and β-isomer, mp 208-210°. LD50 orally in male, female rats: 43, 18 mg/kg (Gaines).

Caution

Potential symptoms of overexposure are skin irritation; nausea, confusion, agitation, flushing, dry mouth, tremors, convulsions, headache. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 126.

Use

Insecticide.