The synthesis of enamines and ketimines using molecular sieves

The synthesis of enamines and ketimines from the corresponding carbonyl compound and amine in high yield at room temperature is described using a commercial silica‐alumina cracking catalyst to catalyze the reaction and a suspended molecular sieve type A to shift the equilibrium. The mixture of molecular sieve and silica‐alumina can be successfully regenerated. Different solvents, catalysts and molecular sieves have been tested. The combination of cyclohexane, silica‐alumina and molecular sieve type 5A gives the best results; besides the pure powder, pellets type 5A can also be used in combination with silica‐alumina catalyst. The moderate catalytic effect of pellets as such, as reported in the literature, has been traced down to the binding agent present in pelletized material.