An efficient method of chemical modification of BODIPY core

A simple approach to the modification of BODIPY nucleus has been developed. The method is based on the reaction of acetaldehyde-substituted dye with primary amines followed by cyclization of enamine intermediates. This procedure allowed preparing a series of new BODIPY derivatives with functional substituents useful for various practical purposes, including bioconjugation and other biomedical applications. The synthesized BODIPYs annealed to a pyridone fragment are stable compounds and intense fluorophores with emission maximum around 615 nm. This λem may be red-shifted by the introduction of styryl substituent.