Title: Tabun
CAS Registry Number: 77-81-6
CAS Name: Dimethylphosphoramidocyanidic acid, ethyl ester
Additional Names: ethyl N-dimethylphosphoramidocyanidate; dimethylamidoethoxyphosphoryl cyanide; GA
Molecular Formula: C5H11N2O2P
Molecular Weight: 162.13
Percent Composition: C 37.04%, H 6.84%, N 17.28%, O 19.74%, P 19.10%
Literature References: Nerve gas; potent cholinesterase inhibitor similar in structure and activity to sarin and soman, q.q.v. Prepd from dimethylamidophosphoryl dichloride and sodium cyanide in the presence of ethanol: Holmstedt, Acta Physiol. Scand. 25, Suppl. 90, 26 (1951). Synthesis of dimethylamidophosphoryl dichloride: Michaelis, Ann. 326, 129 (1903). Alternate synthetic route: B. C. Saunders, Some Aspects of the Chemistry and Toxic Action of Organic Compounds Containing Phosphorus and Fluorine (Cambridge, 1957) p 91. Toxicity study: B. Holmstedt, Pharmacol. Rev. 11, 567 (1959). Brief review: Schrader, Die Entwicklung neuer insektizider Phosphorsäure-Ester (Verlag Chemie, Weinheim, 1963) p 3; B. L. Harris in Kirk-Othmer Encyclopedia of Chemical Technology vol. 5 (Wiley-Interscience, New York, 4th ed., 1993) pp 795-816.
Properties: Liquid. Fruity odor reminiscent of bitter almonds. d 1.077. mp -50°. bp760 240°; bp10 120°; bp9 100-108°. nD20 1.4250. IR absorption: Acta Chem. Scand. 5, 1179 (1951). Readily sol in organic solvents. Miscible with water, but quickly hydrolyzed. Destroyed by bleaching powder (chlorinated lime), but gives rise to cyanogen chloride. Extremely poisonous! LD50 i.p. in mice: 0.6 mg/kg (Holmstedt).
Melting point: mp -50°
Boiling point: bp760 240°; bp10 120°; bp9 100-108°
Index of refraction: nD20 1.4250
Density: d 1.077
Toxicity data: LD50 i.p. in mice: 0.6 mg/kg (Holmstedt)
CAUTION: Potential symptoms of overexposure by inhalation are constriction of pupils of the eye, difficulty breathing followed by bronchial constriction, convulsions, death. Also toxic due to absorption through skin and eyes. See Chem. Eng. News 31, 4676 (1953).
Use: Chemical warfare agent. |