L. G. Shagun

Chemistry of Halomethyl Thioketones

The review summarizes and systematizes the authors data on the synthesis and reactivity of halomethyl thioketones. Reactions involving the title compounds as intermediates are also considered. Mechanisms of formation of halomethyl thioketones are discussed in terms of the results of quantum-chemical calculations.

Oxidation of 2-chloro-1-phenylethane-1,1-dithiol

Oxidation of 2-chloro-1-phenylethane-1,1-dithiol with bromine, iodine, and elemental sulfur, as well as under UV irradiation, leads to formation of 1,4-bis(chloromethyl)-1,4-diphenyl-2,3,5,6-tetrathiane in 50–95% yield. Oxidation of the same substrate with selenium dioxide gives 1,5-bis(chloromethyl)-1,5-diphenyl-2,4-dithia-3-selenapentane-1,5-dithiol. On heating to 60°C, the latter loses selenium to afford 1,4-bis-(chloromethyl)-1,4-diphenyl-2,3-dithiabutane-1,4-dithiol.

Unexpected Reaction of 2-Chloro-1-Phenylethane-1,1-dithiol with Hydrazine- A New Route to 4,5-Dihydro-1,2,3-thiadiazoles

The reaction of 2-chloro-1-phenylethane-1,1-dithiol with hydrazine gave an unexpected product, 2-hydrazono-1-phenylethane-2,2-dithiol, which underwent intramolecular ring closure to 5-phenyl-4,5-dihydro-1,2,3-thiadiazole in 69% yield. Elementary steps of the process were studied by quantum-chemical methods, and their kinetic and thermodynamic parameters were determined.

Organylthiochloroacetylenes: IX. Reactions with geminal and vicinal dithiols

Alkylthiochloroacetylenes react with geminal (in ether) and vicinal (in THF) dithiols to form, respectively, functional 1,3-dithiolenes (yield 43%) or 1,3-dithiolanes (yield 34%).

1-Haloethane-2,2-dithiols

Optimal conditions were found for the synthesis of 1-bromopropane-2,2-dithiol and 1-halo-2-aryl- ethane-2,2-dithiols by low-temperature acid-catalyzed hydrosulfurization of the corresponding 1-haloketones RCOCH2X (R = CH3, X = Br; R = C6H5, X = Cl; R = 4-CH3C6H4, X = Cl; R = 4-CH3C6H4, X = Br; R = 1-C10H7, X = Cl). Reaction paths and solvent effect are discussed.

Homopolycondensation of 1-halogenopropane-2-thiones

Homopolycondensation of 1-halogenopropane-2-thiones was studied; the polymers obtained were structurally characterized by ESR, UV, and IR spectroscopy, elemental analysis, and electrochemical methods. Their molecular masses, dark conductivities, and photoconductivities were determined. The capability for film formation on various substrates was investigated. These polymers were found to be new organic metals (Hal=I), semiconductors (Hal=Cl and Br), and photoconductors (Hal=Cl, Br).

Reaction of 1-chloro-2-phenylethane-2,2-dithiol with divalent metal (Cu, Hg, Pb, Fe, Co, and Ni) salts

Reactions of 1-chloro-2-phenylethane-2,2-dithiol with lead(II) acetate and mercury(II) chloride lead to 1-chloro-2-phenylethane-2,2-dithiolates of lead and mercury. The reactions with copper(II) chloride, iron(II) sulfate hydrate, cobalt (II) chloride hydrate, and nickel(II) acetate give metal-containing compounds C16H18S4M. The1H NMR, IR, and ESR spectra of the obtained compounds were recorded; their specific dark electroconductivities and activation energies of dark conductivity were determined, and their film-forming ability was studied.

Quantum-chemical study of the molecular and electronic structure of 2,2′-dithiodi(2-methyl-2,3-dihydro-1,4-thiazino[2,3,4-i,j]quinolinium)

Conformational isomerism of 2,2′-dithiodi(2-methyl-2,3-dihydro-1,4-thiazino[2,3,4-i,j]quinolinium) has been studied by semiempirical MNDO and AM1 methods. Six symmetrical and unsymmetrical stationary states have been found. Optimum intramolecular rotations around single bonds have been considered. The possibility of the inversion of the reaction centers in nucleophilic and electrophilic reactions depending on the conformational state of the molecule has been shown. The spatial structure of one of the conformers found is similar to that typical of (−)-cystine. The observed constancy of some geometric and electronic parameters makes it possible to study the principal physicochemical properties of dithiazinoquinolinium compounds by the most sophisticatedab initio methods using small model structures, which are constructed by taking into account the variability of other geometric parameters, as an example.