2-Aminocyclopentene-1-carbodithioic acid (ACDA) and its N-/S-alkyl derivatives of methylsilicon(IV)
chloride have been synthesized by the reactions of MeSiCl3 with sodium salt of ACDA and its
N-/S-alkyl derivatives in 1:1 and 1:2 molar ratios. All these complexes have been characterized by
elemental analysis, molecular weight measurements and spectroscopic (IR, 1H and 13C NMR) studies.
The central silicon atom is coordinated to two sulphur atoms or one sulphur atom and one nitrogen
atom of the ligand moiety in all of these derivatives, resulting in five and six coordination.
We have proposed a method for the synthesis of previously unknown bromo xanthenes using the reagent PBr3/DMF as a rearrangement initiator. Bromo derivatives of xanthenes in the form of organic perchlorates were prepared by reacting the corresponding benzo(naphtho)dioxin-4(1)-ones with a three-fold excess of Vilsmeier-Haack PBr3/DMF reagent at 1100C for 2 hours, followed by the addition of sodium perchlorate. The conditions for the synthesis of formyl derivatives of xanthenes under conditions of acid hydrolysis were selected. The structure of the compounds was confirmed by 1H and 13C NMR spectral data and mass spectrometry. Preliminary studies showed that it is possible to selectively replace the dimethylamino group and the bromine atom with various nucleophiles in bromo derivatives of xanthenes, which opens up wide possibilities for the synthesis of low-molecular building blocks and dyes.
Monoorganosilicon(IV) Complexes of 2-Aminocyclopentene-1-carbodithioic
Acid and its N-/S-Alkyl Derivatives: Synthesis and Characterization