Reductive N-methylation of alkanolamines with paraformaldehyde in the presence of cobalt catalysts

Abstract Herein a simple method for N-methylation of ethanolamines with paraformaldehyde as a dual methylation and reducing agent has been investigated. Two new cobalt complexes, Co[Methyl 6-(morpoline methyl) picolinate]2Cl2 and Co(2,6 bis morpholine methyl pyridine)Cl2 were prepared and applied as homogeneous catalyst in reductive methylation reaction. All experiments have progressed with excellent conversion and selectivity toward N,N dimethyl ethanolamine. On the other hand, Pyrolysis of prepared cobalt complexes on activated carbon at 550 °C leads to the formation of cobalt oxide nano-particles. These heterogeneous catalysts were shown similar activities in this reaction. Single-crystal X-ray crystallography, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were used for characterization of prepared catalysts.