M. Israel, L. Jones
Oct 1, 1971
Citations
0
Influential Citations
24
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
Reaction of ethyl acetoacetate with 3,4-diaminopyridine can theoretically give rise to the iso-meric dihydrodiazepinones 1 and 3. However, only one of these (compound 1) was formed on direct condensation of the reactants in boiling toluene. The preparation of 3 required the synthesis of the pyridylaminocrotonate 2, which cyclized under conditions of base catalysis. When subjected to dry fusion, both diazepine derivatives rearranged to give isomeric isopropenylpyridoimidazol-ones. The structures of these rearranged products were used to characterize the diazepines from which they were derived, according to a technique previously described (20,21). Our results contradict a recent report (17) ascribing structure 3 to the product from 3,4-diaminopyridine and ethyl acetoacetate in boiling xylene.