3575. Endothall

Nomenclature

CAS number: 145-73-3
7-Oxabicyclo[2.2.1]heptane-2,3-dicarboxylic acid; 3,6-endoxohexahydrophthalic acid; endothal.
C8H10O5; mol wt 186.16.
C 51.61%, H 5.41%, O 42.97%.

Description and references

Prepn: Olin, US 2550494 (1951 to Sharples Chemicals). Of the three possible isomers, the exo-cis form has the greatest biological activity. Fate in the environment and toxicity: Simsiman et al., Residue Rev. 62, 131-174 (1976); T. B. Gaines, R. E. Linder, Fundam. Appl. Toxicol. 7, 299 (1986).

Chemical structure

Properties

Solubility of the acid in g/100 g at 20°: water 10; acetone 7; benzene 0.01; methanol 28. Converted to the anhydride at 90°. LD50 in adult male, female rats (mg/kg): 57, 46 orally (Gaines, Linder).

Derivative

Dipotassium salt.

Nomenclature

Aquathol (Elf Atochem); Aquathol K (Elf Atochem).
C8H8K2O5; mol wt 262.34.
C 36.63%, H 3.07%, K 29.81%, O 30.49%.

Caution

May be very irritating to skin, eyes, mucous membranes. Ingestion may cause severe G.I. inflammation with erosion. See Clinical Toxicology of Commercial Products, R. E. Gosselin et al., Eds. (Williams & Wilkins, Baltimore, 5th ed., 1984) Section II, p 342.

Use

Herbicide; defoliant.