The doctoral Thesis is prepared as a set of thematically unified scientific publications, which summarizes research on the use of the azido group in synthetic methodology – for inducing regioselectivity and reactivity in annelated pyrimidines and in materials science, specifically the development of new primary explosives. The Thesis examines pyrido[2,3 d]pyrimidines and pyrido[3,2 d]pyrimidines as a new type of structures, which has been investigated for reactivity; purines, for which a new type of ring-opening reaction has been discovered; pyrimidopyrimidine based on the designed binary energetic compound C6N16 and annelated diazidopyrimidines for which energetic profile was determined.