Synthesis of 2‐substituted‐3‐nitroimidazo[1,2‐<i>b</i>]pyridazines as potential biologically active agents

Abstract

Abstract A new heterocyclic reductive alkylating agent, 6‐chloro‐2‐chloromethyl‐3‐nitroimidazo[1,2‐ b ]pyridazine, was synthesized for the first time. It was shown to react under phase‐transfer catalysis conditions with 2‐nitropropane anion by an S RN 1 mechanism to give excellent yield of isopropylidene derivative formed from a base‐promoted nitrous acid elimination of C‐alkylation product. Extension of this S RN 1 reaction to various nitronate anions led to a new class of 3‐nitroimidazo[1,2‐ b ]pyridazine derivatives bearing a trisub‐stituted double bond at the 2‐position.