The reaction of imidazo[1,5‐a]pyridines with methyl‐ and phenyltriazolinediones and with diethyl azodicarboxylate

Imidazo[1,5‐a]pyridines react in one of two ways with methyl‐ and phenyl triazolinediones and diethyl azodicarboxylate to give either Michael type addition products at C‐3 or C‐1, or novel 1,2,4‐triazolines. The nature of the product depends upon the dienophile and the substitution pattern of the imidazo[1,5‐a]pyridine.