Carbonylation of benzyl chloride in a biphasic system using phase transfer catalysts

Abstract

Carbonylation of benzyl chloride to phenyl acetic acid is of great importance, from synthesis as well as catalyst chemistry point of view. This paper presents a study of phase transfer catalysed carbonylation of benzyl chloride in a biphasic liquid mixture as reaction medium, under very mild conditions (14 atm & 338K). The role of different phase transfer catalysts in promoting the Pd complex catalysed reaction is found different. Quaternary ammonium halides were found to be better phase transfer agents for this reaction. Different organic solvents as the second liquid phase also played their own role in changing the activity of the catalyst and selectivity to phenyl acetic acid. An increase in the ligand concentration reduced the deactivation of the Pd complex catalyst to Pd metal thereby increasing the activity of the catalyst considerably.