The monography was dedicated to the research directed to the synthesis, transformations and studies of the biologically active substances having multidisciplinary scientific and technical application areas. For the first time, synthesized and functional properties of some different di-, tetra-, hexapyrimidines-derivatives of cyclic thioureas, which are a new generation of multifunctional compounds and their carboxylic-based compounds were examined, the antimicrobial properties of these compounds were studied with the laboratory experiments and was approved that they have active physiologically active compounds compared to their analogues.