Crystal structure of 2,3,5,6-tetrakis[(methylsulfanyl)methyl]pyrazine

The title compound, C12H20N2S4, synthesized by the reaction of 2,3,5,6-tetrakis(bromomethyl)pyrazine with sodium methanethiolate, crystallizes with a half -molecule in the asymmetric unit. The whole molecule is generated by inversion symmetry; the inversion centre being located in the centre of the pyrazine ring. The molecule has an S-shaped conformation with two (methylsulfanyl)methyl substituent arms directed above the plane of the pyrazine ring and two below. The C(H3)—S—C(H2)—C(aromatic) torsion angles are 70.47 (18) and −67.65 (17)°, respectively. In the crystal, molecules are linkedviaweak C—H...S hydrogen bonds, forming chains along [001] and enclosingR22(12) ring motifs. The chains are linked by further weak C—H...S hydrogen bonds, forming sheets lying parallel to (101).

A New Approach to Imidazo[1,5-a]indole Derivatives

Reaction of indole-2-carbonyl isothiocyanate (1) with sodium methanethiolate afforded 1-thioxo-1H-imidazo[1,5-a]indol-3(2H)-one (3). Its methylation with methyl iodide in the presence of lithium hydride in dimethylformamide, or potassium carbonate in acetone resulted in the formation of corresponding S- and N-methyl derivatives 4 and 5. N-(Indole-2-carbonyl)thiocarbamates and N-(indole-2-carbonyl)thioureas prepared by treatment of isothiocyanate 1 with corresponding nucleophilic reagents were S-methylated with methyl iodide in acetone in the presence of potassium carbonate. The obtained N-(indole- 2-carbonyl) substituted thiocarbonimidates 15, 16 and isothioureas 17-20 afforded by treatment with lithium hydride in dimethylformamide the derivatives of imidazo[1,5-a]- indol-3-one 23-28 in 49-87% yields. Antifungal activity of the prepared compounds has been examined, using the fungus Bipolaris leersiae. 1-Methylsulfanyl-3H-imidazo-[1,5-a]- indol-3-one (4) exhibited the highest antifungal activity.

Thioxanthene derivatives with neurotropic activity; synthesis of 9-(3-dimethylaminopropylidene)-2-(methylthiomethyl)thioxanthene and of some related compounds

A reaction of 2-(bromomethyl)thioxanthone with sodium methanethiolate with sodium methanethiolate gave 2-(methylthiomethyl)thioxanthone (II) which was transformed by treatment with 3-dimethylaminopropylmagnesium chloride to the tertiary alcohol IV. Its dehydration by heating with dilute sulfuric acid afforded the title compound I. An attempt at preparing the analogous 2-(methoxymethyl) derivative proceeded similarly but failed in the stage of the acid-catalyzed dehydration of the tertiary alcohol V. Acids VIII-XII and the nitrile XIII were prepared as potential intermediates. Compound I has properties of a tranquilizer with a weak cataleptic activity.