Journal of Saudi Chemical Society (May 2019)
A hierarchically zeolite Y for the N-heterocyclic compounds synthesis
Abstract
High activity and selectivity of the hierarchical H-Ymmm zeolite in the synthesis of practically important pyridines (by interaction of C2–C4 alcohols with formaldehyde and ammonia, cyclocondensation of acetaldehyde and propanal with ammonia), dialkyl quinolines (by reaction of aniline with aldehydes) and alkyl dihydroquinolines (by reaction of aniline with ketones- acetone, acetophenone) were revealed in the research.The advantages of the micro-meso-macroporous H-Ymmm zeolite over the microporous H-Y zeolite in the synthesis of pyridines and quinolines were demonstrated. In the products formed by the reaction of ethanol with formaldehyde and ammonia, picolines (up to 63%) and lutidine are predominant in H-Ymmm, Pb-H-Ymmm and Fe-H-Ymmm zeolites. The interaction of n-propanol (n-butanol) with formaldehyde and ammonia in the presence of H-Ymmm zeolite with high selectivity produced 3,5-lutidine (up to 90%) or 3,5-diethylpyridine (85%). H-Ymmm zeolite makes it possible to prepare 2-methyl-5-ethylpyridine with 87% selectivity (reaction of acetaldehyde with ammonia) and 2-ethyl-3,5-dimethylpyridine with 58% selectivity (reaction of propanal with ammonia).The synthesis of dialkylquinolines and dialkyltetrahydroquinolines with a total selectivity of 65–73% by the interaction of aniline with C3–C5 aldehydes has been carried out. The dihydroquinoline derivatives with the selectivity of up to 70% have been synthesized by the reaction of aniline with ketones (acetone, acetophenone). Keywords: N-heterocyclic compounds synthesis, Pyridines, Dialkyl quinolines, Alkyl dihydroquinolines, A hierarchically zeolite Y