A. A. Zubarev

Reductive desulfurization of 3-cyano-2-methylthiopyridines under the action of Raney nickel

The action of Raney nickel on substituted 3-cyano-2-methylthiopyridines was studied. Under conditions of catalytic hydrogenation, the reaction yields a mixture containing the aminosulfide resulting from reduction of the nitrile group with retention of the methylthio group, the nitrile resulting from elimination of the methylthio group, and the amine resulting from both reduction of the nitrile group and elimination of the methylthio group. Treatment of 3-cyano-2-methylthiopyridines with a large amount of Raney nickel under desulfurization conditions induces simultaneous elimination of the methylthio group and reduction of the nitrile group to the aminomethyl group. When reductive desulfurization is carried out in methanol or THF, primary amines are formed, while the reactions in isopropyl or ethyl alcohol give secondary or tertiary amines, which are formed upon alkylation of the amino group with alcohols.

Synthesis of 2-alkyl-2-(3-cyanopyridin-2-ylthio)propionic acids

Derivatives of 2-alkyl-2-mercaptopropionic acid were synthesized based on the substituted 3-cyanopyridin-2(1H)-thiones. The synthesis was carried out by the heating of a mixture of thione, alkyl methyl ketone, and chloroform in the presence of a base. The reaction proceeds readily for acetone, whereas alkyl methyl ketones require a prolonged heating in the presence of a phase-transfer catalyst. Methyl esters were prepared from the acids obtained.

Sodium bis(2-methoxyethoxy)aluminum hydride in reactions with 3-cyano-6-methylpyridine-2(1H)-thione and 3-cyano-6-methyl(4,6-dimethyl)-2-methylthiopyridines

The reactions of sodium bis(2-methoxyethoxy)aluminum hydride with 3-cyano-6-methylpyridine-2(1H)-thione and 3-cyano-6-methyl-2-methylthiopyridine afforded 3-aminomethyl-6-methylpyridine-2(1H)-thione and azomethine of the pyridine series, respectively. The corresponding reaction with 3-cyano-4,6-dimethyl-2-methylthiopyridine gave rise to azomethine, substituted 3-aminomethylpyridine, and substituted dipyridylmethane.

3-Cyanopyridine-2(1H)-thiones and 3-cyano-2-(methylthio)pyridines in the synthesis of substituted 3-(aminomethyl)pyridines

The reactions of substituted 3-cyanopyridine-2(1H)-thiones and 3-cyano-2-(methylthio)pyridines with lithium aluminum hydride in anhydrous diethyl ether afforded the corresponding 3-aminomethyl derivatives, which were used in the synthesis of the corresponding amides.

Synthesis of 2-alkylthio-6-methylpyridine-3-carbaldehydes

The action of sodium bis(2-methoxyethoxy)aluminum hydride and its complex with piperidine on 2-alkylthio-3-cyano-6-methylpyridines and on their esters in anhydrous ether yielded 2-alkylthio-3-formyl-6-methylpyridines. The aldehydes obtained undergo condensation with malononitrile and methyl cyanoacetate to give the corresponding hetarylidene derivatives.

Reduction of Derivatives of α-Arylidene-α-(2-Thiazolyl)acetonitrile with Lithium Aluminum Hydride

The action of lithium aluminum hydride on derivatives of α-arylidene-α-(2-thiazolyl)acetonitrile in absolute ether leads to reduction of the nitrile group without affecting the double bond conjugated with it. The reaction products are the corresponding substituted allylamines.