Pyridine bases were prepared by reactions of aldehydes(formaldehyde

acrolein and/or acetaldehyde)with ammonium acetate

using acetic acid as solvent

in a refluxing tank reactor under atmospheric pressure.Quantum chemical and thermodynamic calculations were conducted to analyze the configurations and charges of acrolein and propylene imine and to investigate the electrostatic interaction

frontier molecular orbital and energy changes during the formations of intermediate dihydropyridine and product 3-methyl pyridine.Based on these results

a reaction mechanism was proposed for the formation of 3-methyl pyridine from acrolein and ammonia

and also

a general rule was summarized for the reaction of aldehyde with ammonia to form pyridine bases.The products distribution predicted theoretically was consistent with that obtained by experiment.