Azoalkene Route to Methyl 2,5-Dimethyl-4-[2-(phenylmethyl)benzoyl]-1H-pyrrole-3-carboxylate (FPL 64176) and Analogues: Synthesis of 1-(BOC-amino)pyrrole-3-carboxylates and Their Conversion to 1H-Pyrroles via 1-Aminopyrroles

Abstract

A new route to the calcium channel activator methyl 2,5-dimethyl-4-[2-(phenylmethyl)benzoyl]-1H-pyrrole-3-carboxylate (FPL 64176) and analogues is presented. Reaction of activated diones with BOC-azoalkenes gave pyrroles with the required functionality but having an extra 1-(BOC-amino) substituent. This group was readily removed in two steps to give the required 1H-pyrroles.