Amines alkoxylamines

Primary amines (RNH2) also add reversibly to ketones or aldehydes to give imines (Schiff bases) and related compounds via the intermediate hemiaminals. The position of the equilibrium depends on the structure of the amine and the carbonyl compound. With alkylamines, the equilibrium favors the carbonyl compound, but it can be driven to the imine by removal of H20. With hydrazines (R2NNH2) and hydroxyl-and alkoxylamines (RONH2), the equilibrium greatly favors the hydrazone, oxime, or oxime ether, and it is difficult to drive the reaction in the reverse direction. Secondary amines (R2NH) can form hemiaminals, but they cannot form imines. 

An ethereal soln. of p-chlorobenzaldehyde dimethylhydrazone added dropwise at —10 to 36 to a soln. of phenyllithium prepared from bromobenzene and Li in ether, stirring continued for several hrs. N- (phenyl-p-chlorophenylmethyl) -N jN -dimethyldrazine. Y 86%. F. e., also sec. amines from azomethines (cf. Synth. Meth. 4, 643), and alkoxylamines from alkoximes, s. A. Marxer and M. Horvath, Helv. 47, 1101 (1964). 

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