摘要:
Reactions of 2,6-disubstituted 1,4,3,5-octathiadiazine-4,4-dioxides with cyano-containing compounds (nitriles, thiocyanates, NN-disubstituted cyanamides) proceeding with replacement of imine fragment in dioxide by corresponding fragment of cyanide were investigated. The limits of the reaction were revealed determined by electronic effects of substituents R-1 and R-2 in dioxide and R-3 in cyanide. Transimination occurred in dioxides with strong electron-withdrawing substituents R-1 (CCl3, CBr3, C6F5) and weak acceptor or donor substituents R-2 (4-NO2C6H4, 4-ClC6H4, CH3) under the action of compounds (RC)-C-3=N with cyano groups of relatively high nucleophilicity (R-3 = 4-ClC6H4, C6H5, (CH3)(2)CHS, piperidino, morpholino, diethylamino), on the one hand, and with strong electron-withdrawing substituents R-3 (CCl3) on the other hand.