Synthesis and biological evaluation of 7-azaindole derivatives, synthetic cytokinin analogues

Cytokinins, N6-substituted adenine derivatives, are plant hormones playing important roles in various processes in plant development. Furthermore, cytokinins and their derivatives are able to control mammalian cell apoptosis and differentiation. The aim of our study was the synthesis of 7-azaindole derivatives as cytokinin analogues with the Hartwig–Buchwald coupling reaction in order to evaluate their biological properties on human myeloblastic leukaemia cells (HL-60 cell line). All these compounds presented a cytotoxic activity on HL-60 cells especially the 4-phenylaminopyrrolo[2,3-b]pyridine and the 4-phenethylaminopyrrolo[2,3-b]pyridine.