The palladium acetate-catalyzed synthesis of benzophenone in the mixture of water and ionic liquid is described. The Pd(OAc)2-H2O-[bmim][PF6]catalytic system is a desired green midium and is superior to the previous methods in organic systems in terms of reaction conditions, efficiency, and reaction time. It can be recovered and reused eight times with high efficiency and the use of expensive and environmentally unfavorable phosphine ligand is avoided.
Four novel compounds containing two pyridazinone units attached to one benzene or pyridine ring, protected and deprotected 1,5-di[3（2H）-pyridazinon-6-yl]benzene and 2,6-di[3（2H）-pyridazinon-6-yl]pyridine were synthesized in eight steps, which provided a useful method for the preparation of pyridazinone derivatives via the Stetter and cyclization reactions. Their structures were characterized by ^1H NMR, ^13C NMR, and HRMS.
