A recoverable catalyst Co(salen) in zeolite Y for the synthesis of methyl N-phenylcarbamate by oxidative carbonylation of aniline

A green process for the synthesis of methyl N-phenylcarbamate (MPC) by the oxidative carbonylation of aniline was studied. In this process, Co(salen) complexes were successfully encapsulated in zeolite Y by a flexible ligand method. The heterogeneous catalysts were characterized by AAS, BET, IR, TGA, XRD and XPS. The catalytic activities of the encapsulated catalysts and their homogeneous analogues were examined in the oxidative carbonylation of aniline to MPC. Under the conditions of aniline (11 mmol), encapsulated catalyst (0.5 g), KI (0.365 g), CO/O2 ratio 9:1, 4 MPa, 170 °C, 3 h, Co(salophen)(OH)2–Y catalyst shows the highest activity with the conversion of 67.1% and the selectivity of 77.3%. Co(salophen)(OH)2–Y could be recycled at least five times and no significant loss of catalytic activity was observed.

Co(salen) complexes were encapsulated in zeolite Y by a “ship in bottle” method. Such encapsulated complexes were applied as catalysts for the synthesis of methyl N-phenylcarbamate by oxidative carbonylation of aniline. The conversion of 67.1% and the selectivity of 77.3% in the reaction were obtained with Co(salophen)(OH)2–Y. The catalyst could be recycled at least five times without significant loss of its catalytic activity.Figure optionsDownload as PowerPoint slide