Synthesis of new allylidene amino phenol-containing Schiff bases and metal complex formation using trimethinium salts

Abstract

An efficient route for the synthesis of novel Schiff bases from the condensation reaction of 2-substituted 1,3-bis(dimethylamino)-trimethinium salts with diverse aminophenols in the presence of triethylamine in EtOH at reflux is described.

An efficient route to the synthesis of novel zwitterionic pyridinium-cyanopropenides with 3-heteroaryl-substituted trimethinium salts

“…First, trimethinium salts 1 were prepared similar to the previous studies. [26][27][28][29][30][31][32][33] Second, for the synthesis of novel zwitterionic pyridinium-cyanopropenides, trimethinium salts were isolated as perchlorate salts and reacted directly without additional purication were reacted with malononitrile derivatives in the presence of triethylamine in ethanol as a green solvent at reux. Then, In order to optimize the reaction conditions for the synthesis of zwitterionic pyridiniumcyanopropenides derivatives, the model reaction between 1,3bis(dimethylamino)-2-(isoquinolinium-2-yl)trimethinium bis(perchlorate) 3d and ethyl 2-cyanoacetate 2 was investigated in the presence of different bases and solvents.…”

“…In continuation of our interest in the development of trimethinium salts in organic synthesis, 26–30 herein we report a simple and highly efficient synthetic procedure for the preparation of new zwitterionic pyridinium-cyanopropenides from the reaction of trimethinium salts and malononitrile derivatives in the presence of triethylamine in ethanol as a green solvent in excellent yields without any by-products (Scheme 1D).…”