One-pot Synthesis Of Oxalylamino Substituted Indoaniline Dyes

The indoaniline dyes had been synthesized for long but received little attention because their usefulness was limited by a general instability. In recent years, however, with their increasing use as cyan dye images in color photography, indoaniline dyes have been developed to be used in the fields of thermal sublimation transfer, chromogenic sensors and near infrared areas.In chemistry, one-pot synthesis is a strategy used to improve the efficiency of reactions, which is a continuous multi-step chemical reaction of reactants in one reaction system. Mild reaction conditions, simple operation, good selectivity and high yield are advantages of one-pot synthesis, and which can reduce lengthy purification and separation processes of intermediate compound effectively. Meanwhile, it can also reduce human input to some extent, which will save time and resources while increase chemical yield.This one-pot synthesis needs to add reagents for three times in total:firstly, we use oxalyl chloride as starting material, adding ethanol slowly into it to obtain oxalyl chloride monoethyl ester; and then o-aminophenol or m-aminophenol was added to get intermediate; finally, potassium ferricyanide and N,N-diethyl-p-phenylenediamine dihydrochloride was added to conduct condensation. The reaction has been carried out in just one system.The experiment has synthesized two compounds:o-substituted and m-substituted in indoaniline dyes. The stability of the dyes has been compared by analyzing their structures. This work will benefit further rational design or synthesis more complicated structures.