Discovery of hydrazide-based pyridazino[4,5-]indole scaffold as a new phosphoinositide 3-kinase (PI3K) inhibitor for breast cancer therapy.

Herein, the mono and dialkylation of pyridazino[4,5-]indole were achieved with a set of alkylating agents, including amyl bromide, allyl bromide, benzyl bromide and ethyl chloroacetate in the presence of KCO/acetone or KOH/DMSO. The hydrazinolysis of mono and di-esters 10 and 11 gave the target hydrazides 12 and 13, which displayed promising, potent, and significant cytotoxic activity against the MCF-7 cell line with IC values of 4.25 and 5.