1387639-89-5Relevant academic research and scientific papers
Synthesis and properties of cross-conjugated ω,ω′-bis- dimethylamino ketones and dinitriles with N-acetyl- and N-benzylpiperidine cycles
Krasnaya,Tret'Yakova,Kachala,Zlotin
, p. 2014 - 2020 (2011)
Reactions of N-acetyl- and N-benzyl-4-piperidones with aminal of β-dimethylaminoac-rolein yielded ketocyanines bearing piperidine cycle. Reaction of 3-dimethylamino-1,1,3-tri-methoxypropane with 1-acetylpiperidin-4- ylidenemalononitrile in the presence of ionic liquid, 1-butyl-3- methylimidazolium tetrafluoroborate ([bmim]BF4), resulted in cross-conjugated ω,ω′-dimethylamino dinitrile. Protonation of ketocyanines bearing N-acetyl- and N-benzyl-piperidine cycles with Et 2O · HBF4 (1 equiv.) furnished piperidinium salts, while protonation of the latter with Et2O·HBF4 (2 equiv.) afforded doubly charged 4-hydroxypolymethine salts. Unlike protonation, reaction of 3,5-bis(3-dimethylaminoprop-2-enylidene)-1-acetylpiperidin-4-one with Me2SO4 involved only the oxygen atom and led to a singly charged 4-methoxypoly-methine salt. Methylation of 3,5-bis(3- dimethylaminoprop-2-enylidene)-1-benzylpiperidin-4-one with Me 2SO4 (1 equiv.) involved cyclic nitrogen atom and resulted in piperidinium salt; heating of the latter with the excess of Me 2SO4 afforded doubly charged bis-methoxysulfonate. Starting from 4-methoxytetrahydropyridinium salts, meso- methoxythiapentacarbocyanine dyes were synthesized.
