Accelerated Preparation of Pyridazines Enabled by High-Temperature Diazo Cycloadditions in Continuous Flow Mode

Abstract

The effective application of continuous flow chemistry for the generation of substituted pyridazines via the thermal cycloaddition between α-diazo esters and difluorocyclopropenes is reported. Replacing DMF with MeCN and using stoichiometric reactant amounts at a temperature of up to 150 °C safely afforded the pyridazine targets in only 5-15 minutes in yields up to 93%.