Benzodiazepine Coordination Chemistry And Nitrogen Heterocyclic Compounds From Reactions Of Carbonyl Alkynes With O-Phenylenediamines

The presence of heterocyclic compounds in active pharmaceutical ingredients and natural products implicates their importance to synthetic chemistry. Moreover, their inherent structures offer potential as metal-chelators. This work involved the design of simple methods for the construction of new nitrogen-containing heterocycles and to explore examples of coordination complexes. Benzodiazepines and their derivatives are biologically active heterocycles often prescribed as a treatment for anxiety, epilepsy, and insomnia. In addition, benzimidazo[2,1-a]isoquinolines are another class of biologically active heterocycles that are composed of moieties inherent to a wide variety of active pharmaceutical ingredients. Herein, the microwave-assisted reaction in ethanol of o-phenylenediamines with either alk-2-ynones or 2-ethynyl benzaldehydes was found to yield 1,5-benzodiazepines and benzimidazo[2,1-a]isoquinolines, respectively. To facilitate selective coordination of benzodiazepines, new pyridine containing 1,5-benzodiazepine chelators were synthesized and combined with metal reagents to form new benzodiazepine metal complexes characterized by X-ray crystallography.