Catalytic synthesis of N-alkylacrylamide from acrylonitrile and alcohol with solid acids

Catalytic synthesis of N-alkylacrylamides, which are useful monomers for functional polymers, from acrylonitrile and alcohols, such as 1-adamantanol, tert-butyl alcohol, and isopropyl alcohol has been studied using various solid acids including heteropoly compounds and zeolites. For the reaction with 1-adamantanol or tert-butyl alcohol, a heteropoly compound, Cs_2.5H_0.5PW₁₂O₄₀, exhibited a high catalytic performance and water-tolerance. On the other hand, for the synthesis of N-isopropylacrylamide from isopropyl alcohol, a high-silica zeolite, H-ZSM-5 with Si/Al ratio of 37, showed an exceptionally high activity, while it was less active in the reaction with tert-butyl alcohol or 1-adamantanol. This marked effect of reactant alcohol observed for H-ZSM-5 is probably due to shape selectivity. The prominent performance for N-isopropylacrylamide synthesis is attributable to a steric effect of the constrained pores; two reactants might be arranged adequately to form an intermediate in the pores.