Synthese neuer Aryl‐(3,‐dichloro‐4‐pyridazinly)‐ketone und ihre Reaktion mit N,N‐Dinucleophilen

Synthesis of New Aryl (3,6‐Dichloro‐4‐pyridazinyl) Ketones and their Reaction with N,N‐Dinucleophiles The synthesis of the new aryl (3,6‐dichloro‐4‐pyridazinyl) ketones 3a–e vïa Friedel ‐ Crafts acylation of the aromatic compounds 2a–e with 3,6‐dichloro‐4‐pyridazincarbonyl chloride (1) is described. The ketones 3a–e cyclized with N,N‐dinucleophilic reagents to the 3‐aryl‐5‐chloro‐l H ‐pyrazolo[3,4‐ c ]pyridazines 4a–d , and 3a–c are converted into the 3‐aryl‐5‐chloro‐l H ‐pyrazolo[3,4‐ c ]pyridazin ‐ l ‐ethanols 5a–c and to the hitherto unknown ring system of the 5‐aryl‐3‐chloro‐7,8‐dihydro‐9 H ‐pyridazino[3,4‐ e ][1,4]diazepines ( 6a‐c ).