Aniline derivatives dicarbonyl compounds

Solid-solid reactions 2.00 mmol of the 1,3-dicarbonyl compound 1 or 4 and 2.00 mmol of the solid aniline derivative 2 were ball-milled at room temperature for 30 min. After drying of the solid hydrates at 0.01 bar at 80 °C the pure enam-ine ketones 3 or 5 were obtained with quantitative yield. 

Kaupp et al. described that the 1,3-dicarbonyl compounds such as 1,3-cyclohex-anedione, dimedone, and dehydracetic acid reacted in the solid state with aniline derivatives to obtain enamine ketones 250 and 252 in quantitative yields (Scheme 3.66) [18]. Advantages over the solvent synthesis were identified it is unnecessary to use acid catalysis, solvents, or liquid phases. A further benefit of avoiding iminiiim salt intermediates in such synthesis is the lack of workup requirements. 

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