On the Reaction of Triaryl Trithioarsenites, (ArS)₃As, with Octasulfur

Abstract

para‐Substituted with electron donating or electron withdrawing groups triphenyl trithioarsenites, (ArS)3As, and octasulfur in refluxing carbon disulfide or chloroform do not give the triaryl tetrathioarsenates, (ArS)3As=S, as was claimed in the literature for tris(4‐methylphenyl) tetrathioarsenate. In some cases oxidative decomposition to As2O3 and disulfides ArSSAr was found. When equivalent amounts of the same esters and octasulfur were heated at 105 or 150 °C no AsV compound was detected or isolated and again some esters decomposed to As2O3 and disulfides. These experiments demonstrated that the aromatic trithioarsenites do not react with octasulfur, probably because they cannot open the octasulfur ring. These esters in solution react with octasulfur in the presence of a catalytic (10—20 mol%) amount of triethylamine giving disulfides, As2O3 and colored solids which could not be characterized.

The reactions of triethylamine-activated octasulfur with thioarsinites, L2As‒SPh (L = Me, Ph), Bunsen's cacodyl disulfide, Me2As(S)‒S‒AsMe2, and triphenylarsine

“…Instead, some esters decomposed to As 2 O 3 and disulfides, ArSSAr [3,5]. When octasulfur was activated by catalytic amounts of triethylamine [6], the (ArS) 3 As esters gave disulfides, As 2 O 3 , and colored, insoluble to all common solvents, solids which could not be characterized [3]. The same was observed with certain aliphatic esters (RS) 3 As [7].…”

“…In particular, compounds of As(III) having no alkyl or aryl group directly bonded to arsenic behave differently toward S 8 depending on the nature of the compound. Thus, octasulfur oxidized alkaline arsenite, Na 3 AsO 3 , to the trisodium salt of monothioarsenic acid, Na 3 AsO 3 S [1], by a mechanism most probably involving the attack of AsO 3 37 on the penultimate sulfur of À ÀSÀ ÀS 5 À ÀSÀ ÀSÀ ÀAsO 3 27 [2]. Triaryl trithioarsenites, (ArS) 3 As, on the other hand, do not react with S 8 in solution or in the molten state [3] contrary to the earlier reports [4].…”

“…Thus, octasulfur oxidized alkaline arsenite, Na 3 AsO 3 , to the trisodium salt of monothioarsenic acid, Na 3 AsO 3 S [1], by a mechanism most probably involving the attack of AsO 3 37 on the penultimate sulfur of À ÀSÀ ÀS 5 À ÀSÀ ÀSÀ ÀAsO 3 27 [2]. Triaryl trithioarsenites, (ArS) 3 As, on the other hand, do not react with S 8 in solution or in the molten state [3] contrary to the earlier reports [4]. Instead, some esters decomposed to As 2 O 3 and disulfides, ArSSAr [3,5].…”

“…Triaryl trithioarsenites, (ArS) 3 As, on the other hand, do not react with S 8 in solution or in the molten state [3] contrary to the earlier reports [4]. Instead, some esters decomposed to As 2 O 3 and disulfides, ArSSAr [3,5]. When octasulfur was activated by catalytic amounts of triethylamine [6], the (ArS) 3 As esters gave disulfides, As 2 O 3 , and colored, insoluble to all common solvents, solids which could not be characterized [3].…”

Oxidation of structural cysteine residues in thioredoxin 1 by aromatic arsenicals enhances cancer cell cytotoxicity caused by the inhibition of thioredoxin reductase 1

“…As 1-7 ( Fig. 1) were synthesized according to literature: As1-3 were synthesized according to reference [9]; As4 and As5 were synthesized according to reference [21]; As6 was synthesized according to reference [22]; and As7 was synthesized according to reference [23,24]. The purity of the compounds was better than 99% and were characterized by melting point, elemental analyses, IR, NMR and in the case of As7 by X-ray analysis [24].…”