Heptachlor

Heptachlor

Names
IUPAC name 1,4,5,6,7,8,8-Heptachloro-3a,4,7,7a-tetrahydro-4,7-methano-1H-indene
Identifiers
CAS Number	76-44-8 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:34785 Y
ChEMBL	ChEMBL194400 Y
ChemSpider	3463 Y
ECHA InfoCard	100.000.876
KEGG	C14185 Y
PubChem	3589
UNII	7GLS9ACN3L Y
InChI InChI=1S/C10H5Cl7/c11-4-2-1-3-5(4)9(15)7(13)6(12)8(3,14)10(9,16)17/h1-5H Y Key: FRCCEHPWNOQAEU-UHFFFAOYSA-N Y InChI=1/C10H5Cl7/c11-4-2-1-3-5(4)9(15)7(13)6(12)8(3,14)10(9,16)17/h1-5H Key: FRCCEHPWNOQAEU-UHFFFAOYAM
SMILES ClC1/C=C\C2C3(Cl)C(\Cl)=C(\Cl)C(Cl)(C12)C3(Cl)Cl
Properties
Chemical formula	C10H5Cl7
Molar mass	373.32 g/mol
Appearance	White to tan solid
Odor	Camphorous
Density	1.58 g/cm3
Melting point	95 to 96 °C (203 to 205 °F; 368 to 369 K)
Boiling point	135 to 145 °C (275 to 293 °F; 408 to 418 K) at 1-1.5 mmHg
Solubility in water	0.0006% (20°C)
Vapor pressure	0.0003 mmHg (25°C)
Hazards
Flash point	noncombustible
Lethal dose or concentration (LD, LC):
LD50 (median dose)	116 mg/kg (oral, guinea pig) 40 mg/kg (oral, rat) 100 mg/kg (oral, rat) 68 mg/kg (oral, mouse) 100 mg/kg (oral, hamster)
LDLo (lowest published)	50 mg/kg (cat, oral)
LCLo (lowest published)	150 mg/m3 (cat, 4 hr) 200 mg/m3 (mammal, 4 hr)
US health exposure limits (NIOSH):
PEL (Permissible)	TWA 0.5 mg/m3 [skin]
REL (Recommended)	Ca TWA 0.5 mg/m3 [skin]
IDLH (Immediate danger)	Ca [35 mg/m3]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Heptachlor is an organochlorine compound that was used as an insecticide. Usually sold as a white or tan powder, heptachlor is one of the cyclodiene insecticides. In 1962, Rachel Carson's Silent Spring questioned the safety of heptachlor and other chlorinated insecticides. Due to its highly stable structure, heptachlor can persist in the environment for decades. The US EPA has limited the sale of heptachlor products to the specific application of fire ant control in underground transformers. The amount that can be present in different foods is regulated.

Analogous to the synthesis of other cyclodienes, heptachlor is produced via the Diels-Alder reaction of hexachlorocyclopentadiene and cyclopentadiene. The resulting adduct is chlorinated followed by treatment with hydrogen chloride in nitromethane in the presence of aluminum trichloride or with iodine monochloride.

Compared to chlordane, it is about 3–5 times more active as an insecticide, but more inert chemically, being resistant to water and caustic alkalies.

Soil microorganisms transform heptachlor by epoxidation, hydrolysis, and reduction. When the compound was incubated with a mixed culture of organisms, chlordene (hexachlorocyclopentadine, its precursor) formed, which was further metabolized to chlordene epoxide. Other metabolites include 1-hydroxychlordene, 1-hydroxy-2,3-epoxychlordene, and heptachlor epoxide. Soil microorganisms hydrolyze heptachlor to give ketochlordene. Rats metabolize heptachlor to the epoxide 1-exo-1-hydroxyheptachlor epoxide and 1,2-dihydrooxydihydrochlordene. When heptachlor epoxide was incubated with microsomal preparations form liver of pigs and from houseflies, the products found were diol and 1-hydroxy-2,3-epoxychlordene. Metabolic scheme in rats shows two pathways with the same metabolite. The first involves following scheme: heptachlor → heptachlor epoxide → dehydrogenated derivative of 1-exo-hydroxy-2,3-exo-epoxychlordene → 1,2-dihydrooxydihydrochlordene. The second involves: Heptachlor → 1-exo-hydroxychlordene → 1-exo-hydroxy, 2,3-exo-epoxychlordene → 1,2-dihydrooxydihydrochlordene.