Yu. A. Sharanin

6-Amino-5-cyano-1H,4H-pyrazolo[3,4-b]pyrans

The reaction of 3-methyl-1-phenyl-5-pyrazolene with arylideneamino nitriles in alcohol leads to the formation of 3-methyl-4(1-aryl-2,2-dicyanoethyl)-5-pyrazolones, which are readily cyclized in the presence of bases to the corresponding 6-amino-5-cyano-3-methyl-4-aryl- 1H,4H-pyrazolo[3,4-b]pyrans. The structures of the intermediate and final products were confirmed by the IR, UV, PMR, and mass spectra.

Synthesis and some reactions of 3-cyanopyridine-2-thiones

New methods for the synthesis of 3-cyanopyridine-2-thiones by the reaction of δ-keto nitroles with sulfur and by condensation of chalcones or benzylideneacetone with cyanothioacetamide are given. The compounds obtained were used in various reactions for the preparation of alkylated products, disulfides, and condensed heterocycles, viz., thieno[2,3-b]pyridines and pyrido[2′,3′:2,3]thieno[4,5-d]-pyrimidines.

SYNTHESIS AND REACTIONS OF CYCLIC NITRILES

Die durch Erhitzen der Nitrile (I) und (II) in Gegenwart organischer Basen gebildeten Cyclohexadiene (III) werden bei weiterem Erhitzen mit Basen zu den Anilinen (IV) gespalten.