A Sustainable Catalyst-Free Approach to Bipyrazoles Under Batch and Flow Chemistry Techniques

Abstract

We have developed an efficient and sustainable approach for the synthesis of 4,4′-bipyrazole derivatives from spirocyclopropanyl-pyrazolone and hydrazine under mild conditions. This methodology is catalyst-free, operating effectively in both batch and continuous flow processes. The flow synthesis allows the production of products up to 110 mg/h which provides industrial applicability and scalability. Additionally, 4,4’-bipyraole has been transformed into a triphenyl-substituted pyrazole derivative.