Lithiation and electrophilic substitution of dimethyl triazones

The lithiation and electrophilic substitution of dimethyl triazones is described. Directed lithiation or tin–lithium exchange of dimethyl triazones afforded the corresponding dipole stabilized nucleophiles that were trapped with various electrophiles. Keto-triazone derivatives accessed by acylation of such nucleophiles were readily converted into the corresponding imidazolone heterocycles.