Reaction of N-aryl substituted maleimides with aliphatic ketazines leads to the formation of 4,5-dihydropyridazin-3(2H)-ones in moderate yields. The reaction proceeds through 1,4-addition of an azine to the maleimide double bond, as confirmed by separation of the corresponding adducts in some cases, which are then converted into 4,5-dihydropyridazin-3(2H)-ones. In addition, the solid-state synthesis of 4,5-dihydropyridazin-3(2H)-ones is demonstrated for the first time. 2011 Published by Elsevier Ltd.
- N-Arylmaleimides Aliphatic ketazines 4
- 5-Dihydropyridazin-3(2H)-ones Solvent-free conditions Microwave irradiation Michael addition product