Synthesis of Acetamide Derivatives using S-MWCNT and S-MC as an Efficient Heterogeneous Catalysts

Sulphate modified multiwalled carbon nanotubes (S-MWCNT) and Mesoporous carbon (S-MC) catalysts were prepared by wet impregnation method. These materials were characterized by different analytical techniques such as Powder-XRD, BET surface area analysis, SEM-EDS and TEM analysis to evaluate their bulk and surface properties. Surface acidity of the catalyst was measured by TPD-NH3 technique, as well as n-butyl amine titration. The estimated surface acidity of S-MWCNT and S-MC using n-butyl amine titration was found to be 0.82 and 1.75 mmol/g respectively. The catalytic activity of these materials was investigated in the synthesis of acetamide derivatives using aromatic acids with substituted aromatic amines in a liquid phase reaction. The reaction conditions were optimized to achieve good % yield of the products. In general S-MC catalyst exhibited good catalytic activity and gave higher % yield of the respective acetamides than S-MWCNT. This is attributed to higher surface acidity of S-MC, however the catalyst was found to be non-recyclable. S-MWCNT exhibited moderate % yield and 100% selectivity towards the formation of products. S-MWCNT catalyst was recycled up to 5 times with a consistent % yield of the respective acetamide derivatives. The synthesized acetamide derivatives were analyzed by M.P, 1HNMR techniques.