Synthesis and characterization of phenoxarsin‐10‐yl 2‐R2N‐cyclopent‐1‐ene‐1‐carbodithioate (R = H, C2H5, cyclo‐C6H11CH2) and the crystal and molecular structure of the 2‐amino (R = H) derivative

Abstract

AbstractPhenoxarsin‐10‐yl derivatives of 2‐amino‐cyclopent‐1‐ene‐1‐carbodithioic acid, (ACDA), and its N‐alkyl derivativesO(C6H4)2 AsS2C—C5H6— NHR‐2 (R = H, CH2CH3, CH2C6H11,), have been prepared by reacting O(C6H4)2AsCI with the corresponding ACDA 1,1‐dithioic acid. The compounds were obtained by stirring stoichiometric amounts of the reagents in ethanol, over 24 h, at room temperature. The scale of the preparations were in the order of 2 mmol and the yields of the compounds ca 75%. The reactions were carried out in absolute ethanol. The compounds were characterized by IR, mass and NMR (1H, 13C) spectroscopy. The molecular structure of O(C6H4)2AsS2C—C5H6—NH2‐2 was determined using X‐ray diffractometry, achieving an R‐value of 6.3%; this compound is monomeric and contains an asymmetric monometallic biconnective 1,1‐dithiolato ligand [As—S(1) 2.272(2) å, As … S(2) 3.125(2) å]. An intramolecular hydrogen bond is established between one hydrogen atom of the NH2 group and the sulfur [S(2)] atom involved in the secondary interaction to arsenic. The dihedral angle (150.3(3)°) of the phenoxarsine moiety is practically unaffected by substitution of chlorine on arsenic by the carbodithioato ligand.