The 
equilibrium
favours the product
formation due to rapid
dehydration of the
intermediate to form
>C=N-Z Z = Alkyl, aryl, OH, NH2, C6H5NH, NHCONH2, etc Table 8 2: Some N-Substituted Derivatives of Aldehydes and Ketones (>C=N-Z)
-H
Ammonia
Imine
-R
Amine
—OH
Hydroxylamine
Oxime
—NH2
Hydrazine
Hydrazone
Phenylhydrazine
Phenylhydrazone
Z
Reagent name
Carbonyl derivative
Product name
Substituted imine
(Schiff’s base)
* 2,4-DNP-derivatives are yellow, orange or red solids, useful for characterisation of aldehydes and ketones