Synthesis of pyrrolo[3,4‐<i>c</i>]pyridazines

Abstract

Abstract We have prepared the pyrrolopyridazines 7a‐f starting from the diazo compounds 4 . The synthesis involves a tandem condensation‐aza‐Wittig reaction or a combination of Wittig and aza‐Wittig reactions as key steps. Reaction of pyridazine 7d with diazomethane results in C ‐methylation to yield 7g . Sodium borohydride reduces 7d to either the dihydropyridazine 12 or the hydroxylactam 13b depending of the reaction conditions.