The reaction between acetone and ammonia. III. Reduced pyridine, deriviaties

Abstract

The preparation of 2,2,4,6-tetramethyldihydropyridine by the reaction of acetone and ammonia at temperatures of 100-180 °C. has been studied; using an alkaline catalyst at 120 °C. for 3 hr, a yield of over 60 per cent. can be obtained. This dihydro-pyridine is identical with the product obtained by Matter (1948) in the pyrolysis of 2,2,4,4,6-pentamethyltetrahydropyrimidine Possible mechanisms for its formation are discussed. Catalytic hydrogenation over Raney nickel leads to tetramethyl-piperidine, while with palladium a partial reduction product, formulated as 2,2,4,6-tetramethyl-2,3,4,5-tetrahydropyridine is obtained ; the chemistry of these reduction products has been examined.