Flow synthesis of N-alkyl-5-methyl-2-pyrrolidones over Ni2P/SiO2 catalyst

N-alkyl-5-methyl-2-pyrrolidones are an attractive alternative to the common solvent N-methyl-2-pyrrolidone (NMP) and can be used as starting materials for synthesis of various valuable chemicals. Reductive amination of alkyl levulinates derived from biomass feedstock is a promising method for production of these compounds. In the present work, N-alkyl-5-methyl-2-pyrrolidones were obtained in excellent yields by reductive amination of ethyl levulinate with alkylamines over SiO2-supported nickel phosphide in a flow reactor using molecular hydrogen as a reducing agent. At the same time, aromatic amines and 1-nitropropane give a lower yield of the corresponding pyrrolidones. The influence of the solvent nature, temperature, pressure, hydrogen and liquid flow rates on the catalyst performance was studied.

Automated summary

In this study, N-alkyl-5-methyl-2-pyrrolidones were efficiently synthesized at high yields through reductive amination using a SiO2-supported nickel phosphide catalyst and molecular hydrogen as the reducing agent in a flow reactor. Additionally, the influence of the solvent nature, temperature, pressure, hydrogen, and liquid flow rates on the catalyst performance was investigated. The results showed that the reaction conditions play a significant role in the synthesis of the target compounds.