Synthesis of All Regioisomers of 2-Aryl Azaindole-3-acetic Acid Derivatives

A novel protocol was developed for synthesizing 2-aryl-substituted azaindole-3-acetic acid derivatives from 2-aminoazacinnamic acid derivatives and aryl aldehydes through an imino-Stetter reaction. Condensation of 2-aminoazacinnamic acid derivatives with aldehydes forms the corresponding aldimines, which are then treated with cyanide to yield the desired 2-aryl-substituted azaindole-3-acetic acid derivatives. Notably, this protocol could be employed for the synthesis of all regioisomers of azaindole-3-acetic acid derivatives by using the appropriate azacinnamic acid derivatives.