A Novel Synthesis of Alkylpyridines from Olefins and Ammonia

Abstract

A novel synthesis of alkylpyridines from some lower olefins and ammonia was studied. In a series of reactions of ethylene with ammonia in the presence of palladium(j) chloride, 27methylpyridine and 5-ethyl-2-methylpridine were predominantly obtained in high yield. when copper(11) chloride as a redox reagent was added to the above system, palladium(jI) chloride was found to function as a catalyst, and both the conversion of ethylene and the selectivity of alkylpyridines were increased remarkably. The optimum conditions for production of alkylpyridines were as follows; the reaction temperature was 200°C and the molar ratios of PdCl2/ C_2CI-I4, CuCl2/C_2CH4, and NH₃/CuCl2 were O.01, 1-1.5, and 5, respectively. Under these conditions, the conversion of ethylene was nearly 65%, and the selectivities for 2-methylpyridine and 5-ethyl-2-methylpyridine were 7, -12% and abuot 48%, respectively. It is assumed that the reaction proceeds via acetaldehyde formed by the catalytic reaction of tetraammine palladium and-copper complex ions with ethylene.