Revisitation of the reaction between Aniline and Formaldehyde. 6. The Accumulated Amide Ester Function from Addition of Carboxylic Anhydrides to N-Methyleneamines or their Trimers.

Some aliphatic carboxylic anhydrides gave excellent yields of the novel addition products to both aliphatic and aromatic N-methyleneimines, starting from their aliphatic and aromatic trimeric cyclic oligomers. A preliminary positive ion mass spectrometric study is here reported. They hydrolyze surprisingly faster than the corresponding acid amides, making necessary the intervention of a special mechanism. The reduction of the acetylamideester of cyclohexylmethyleneimine (3c) with LiAlH4 was also “abnormal”, as it yielded N-methyl-N-ethylcyclohexylamine in quantitative yield.