Synthesis and antimicrobial evaluation of novel polyheterocyclic systems derived from cyclopenta[4',5']pyrido[3',2':4,5]furo[3,2-d]pyrimidine.

The synthesis of new cyclopenta[4',5']pyrido[3',2':4,5]furo[3,2-d]pyrimidin-7-amines have been carried out to study their antimicrobial activity. The biological tests evidenced that some of the synthesized compounds exhibit pronounced antimicrobial properties. A study of the structure–activity relationship revealed that the 3,5-dimethyl-1H-pyrazol-1-yl moiety linked to the carbon C-9 of the pyrimidine plays a decisive role in the manifestation of activity. The influence of 3,5-dimethyl-1H-pyrazol-1-yl group on the Dimroth rearrangement and azide-tetrazole equilibrium has also been examined. [ABSTRACT FROM AUTHOR]