Title: Arsphenamine
CAS Registry Number: 139-93-5
Additional Names: salvarsan
Manufacturers' Codes: Ehrlich 606
Literature References: Originally introduced as an antisyphilitic. Initially characterized as 4,4¢-(1,2-diarsenediyl)bis[2-aminophenol] dihydrochloride; composition was later determined to be of a mixture of cyclic 3-amino-4-hydroxyphenylarsenic species. Prepn: P. Ehrlich, A. Bertheim, US 986148 (1911 to Hoechst); eidem, Ber. 45, 756 (1912); W. A. Christiansen, J. Am. Chem. Soc. 42, 2402 (1920). Toxicity data: J. F. Schamberg et al., Am. J. Syph. Neurol. 18, 37 (1934). Review of structure: A. S. Levinson, J. Chem. Educ. 54, 98-99 (1977). MS determn of chemical composition: N. C. Lloyd et al., Angew. Chem. Int. Ed. 44, 941 (2005).
Properties: Light yellow, somewhat hygroscopic powder. It is odorless, or has a slight odor of the precipitant used. Oxidizes on exposure to air, becoming darker and more toxic. It is poisonous! Sol in water, alc or glycerol, very slightly sol in chloroform or ether. Its aq soln is acid; pH about 3. LD100 i.v. in rats: 140 mg/kg (Schamberg).
Toxicity data: LD100 i.v. in rats: 140 mg/kg (Schamberg)
Arsthinol Arteether Arteflene Artemether Artesunate

The structure of Arsphenamine has been proposed to be akin to the azobenzene (A), but mass spectral studies published in 2005 suggest[1] it is actually a mixture of the trimer B and the pentamer C.

Arsphenamine, also known as Salvarsan and compound 606, is a drug that was introduced at the beginning of the 1910s as the first effective treatment for syphilis, and was also used to treat trypanosomiasis.[2] It is an organoarsenic molecule, and was the first modern chemotherapeutic agent.