Solvent free acid catalysed direct N-alkylation of amines with alcohols using Al grafted MCM-41

• Al grafted MCM-41 showed potential of direct N-alkylation of amines with alcohols.
• Solvent free and base/promotor free N-alkylation method was established.
• Effect of catalyst acidity, reaction conditions and substrates nature were studied.
• Benzylic, primary and secondary alcohols were activated for N-alkylation reaction.
• Deactivated amine substrates could also be alkylated by alcohols.

The catalytic activity of Al grafted MCM-41 (Al-MS) was explored for solvent free acid catalysed direct N-alkylation of amines using alcohols as green alkylating agent to establish a clean method for synthesis of N-alkylated amines. The study revealed that acidity of Al-MS catalyst, reaction conditions and substrate's (amines and alcohols) nature are important factors influencing the N-alkylation reaction. The Al grafted MCM-41 with Si/Al molar ratio of 5 showed excellent activity for N-alkylation of amines with alcohols. The reusability of spent catalyst regenerated by simple washing with acetone was demonstrated for subsequent four reaction cycles.

The Al grafted MCM-41 (Si/Al = 5) showed good to excellent activity in solvent free acid catalysed direct N-alkylation of amines with alcohols giving selective conversion to N-alkylated amines.Figure optionsDownload high-quality image (141 K)Download as PowerPoint slide