The objective of the proposed research is the development of synthetic routes to currently inaccessible azaazulene heteroaromatic compounds. Azaazulenes are isoelectronic and structurally related to compounds of known biological importance. However, due to their non-benzenoid aromaticity azaazulenes are a significant departure from conventional systems. Thus their properties, particularly biological activity, are of interest and will be explored in the proposed study. The recent discovery of biologically active natural products incorporating azaazulene structures further suggests the potential importance of this class of compounds. Information concerning the properties of azaazulenes is lacking because general methods for their synthesis do not yet exist. Five different azaazulene structures have been selected for synthesis. None of these systems has been previously prepared. They range from monoaza- to pentaaza-, with variation in the position of nitrogen within the aromatic azulene framework. Structural variation in this manner will provide insight into the effects of heteroatom substitution. The feasibility of individual reactions in each synthetic sequence is supported by precedent in the chemical literature. Wherever possible, established techniques of organic synthesis will be employed. The parent heteroaromatic azaazulenes as well as precursors will be characterized with regard to their physical and chemical properties. Structural analogy to compounds of recognized activity (e.g. 6-mercaptopurine, metrazol, valium) indicates the need for biological testing. Central nervous system activity assays will be conducted and samples will be submitted to the National Cancer Institute for anti-tumor screening.
