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.