Silica-Alumina Catalyst Support, an Efficient Catalyst for Synthesis of Halogen Substituted 2,6-Bis(imino)pyridines

Silica-alumina catalyst support was found to be an efficient catalyst for the condensation reaction of 2,6-, 2,5-, and 2,4-difluoroaniline and ortho-halogen-aniline with 2,6-diacetylpyridine to afford corresponding 2,6-bis(imino)pyridines in 56-75% isolated yields under extremely mild reaction conditions. The catalyst can be recovered and reused.