Ethyl acetoacetate, reaction with nitric

This reaction consists of the condensation of two molecular equivalents of a 1,3 diketone (or a J3-keto-ester) with one equivalent of an aldehyde and one of ammonia. Thus the interaction of ethyl acetoacetate and acetaldehyde and ammonia affords the 1,4-dihy dro-pyridine derivative (1), which when boiled with dilute nitric acid readily undergoes dehydrogenation and aromatisation" to gb e the diethyl ester of collidine (or 2,4,6-trimethyl-pyridine-3,5 dicarboxylic acid (II)). For the initial condensation the solid aldehyde-ammonia can conveniently be used in place of the separate reagents. 

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