Examination of Pyridazine as a Possible Scaffold for Nucleophilic Catalysis

Pyridazines with amino groups positioned para to each aromatic ring nitrogen and fixed in six-membered rings were prepared. The representative symmetric amino N-Et derivative was found to slightly exceed DMAP in catalytic activity in the acetylation reaction of a tertiary alcohol in C6D6. Nucleophilicity eclipsing that of DMAP was established in competitive reactions using phenacyl bromide as the electrophile, and the unsymmetric N-Et derivative was revealed to have even higher nucleophilicity.