Theophyllinylpyrimidine Scaffolds Undergo Intramolecular Cyclization Reactions to Form 1,3-Diazepines and Imidazopurines

Polyheterocyclic pyrimidinyltheophyllines have been synthesized from pyrimidine and theophylline precursors. Attempts to cyclize these reactive bis‐heterocyclic systems resulted in the formation of the corresponding diazepine moieties. In addition, modification of the reaction conditions led to the formation of imidazo[2,1‐f]purines. Polyheterocyclic pyrimidinyltheophyllines have been synthesized from pyrimidine and theophylline precursors. Attempts to cyclize these reactive bis‐heterocyclic systems resulted in the formation of the diazepine moiety. Modification of the reaction conditions led to the formation of imidazo[2,1‐f]purines.