SYNTHESIS OF PYRIDINE BASE

PROBLEM TO BE SOLVED: To obtain a pyridine base at a high yield by condensing an aliphatic aldehyde and/or a ketone and ammonia in the presence of a specific catalyst in the gaseous phase while repressing reduction of catalytic activity of the catalyst by taking advantage of high activity and excellent thermal stability of the catalyst. SOLUTION: This synthesis of a pyridine base comprises using a crystalline metal aminophosphate (e.g. crystalline silicoaminophosphate) when an aliphatic aldehyde and/or ketone and ammonia are condensed in the presence of a catalyst in the gaseous phase. The preferable acid quantity of the crystalline aminophosphate is 100 micromol or more per gram of the catalyst as saturated adsorption at 100 deg.C when ammonia is used as the adsorptive base, and the preferable metal content is 0.05-0.3 when expressed by molar fraction. The above-mentioned reaction is preferably carried out using ammonia in a quantity of a mole ratio of 1-3 to the total of the aliphatic aldehyde and/or ketone at temperature of 350-550 deg.C and at a space velocity of 100-3000hr .