Pyridazines. LI. On the Reactivity of Pyridazine‐carbaldehydes towards Selected Active‐Hydrogen Compounds

Abstract

Reactions of 3‐pyridazinecarbaldehyde and 4‐pyridazinecarbaldehyde with various active methylene carbanions were studied. The products obtained in Knoevenagel reactions, Wittig‐Horner‐Emmons reactions, and Hantzsch‐type reactions are presented.

Reaction of aromatic aldehydes with β-dicarbonyl compounds in a catalytic system: Piperidinium acetate-1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid

“…[3][4][5][6][7][8][9][10][11] Recently, the results of investigation of Knoevenagel condensation in solutions of imidazolium salts with fluorine containing anions have been reported. 1,2 This reaction is gener ally performed in polar organic solvents (for example, in EtOH or THF), which provide good solvation of CH acid anions and promote dehydration of aldols.…”

“…Apparently, the [Bmim][BF 4 ] and [Pip][OAc] salts complement each other under the reaction conditions: [Pip][OAc] acts as a base, whereas [Bmim][BF4 ] stabilizes the carbanion of the CH acid (presumably, through hydrogen bonding with the involvement of the proton at position 2 of the imid azole ring 27 ). of [Bmim][BF 4 ] and/or [Pip][OAc] to the reaction mixture.…”