The biologically active compounds of pyrimidine, dihydropyrimidinone, and dihydroimidazole have been
synthesized in excellent yield under free solvent conditions. The antibacterial evaluation of the products
showed a high inhibitory effect. Reaction of 2-guanidinobenzothiazole with several active methylene compounds
has revealed formation of the corresponding pyrimidine, dihydropyrimidinone, and dihydroimidazole
derivatives under free solvent conditions in very good yield. All compounds have been characterized
on the basis of IR, 1H NMR, 13C NMR, mass spectrometry, and X-ray.