A new method for the synthesis of 3, 5-disubstituted pyridines is described. Reactions of the N-substituted methanimines 1 with the 8-substituted enamines 2 give l-aza-1, 3-butadienes 3a-i and/or symmetrically 3, 5-disubstituted pyridines 4a-c, eh in moderate to good yields. At reaction temperatures of 150" C the azadienes 3 are the predominant products, and the reaction provides a good route to 1-azadienes with no substituent at the 4-position. At ...