Structural Characterization and Antimicrobial Activities of 7H-Benzo[h]chromeno[2,3-d]pyrimidine and 14H-Benzo[h]chromeno[3,2-e][1,2,4]triazolo[1,5-c] pyrimidine Derivatives.

Three new series of chromene molecules have been synthesized in order to explore their antimicrobial activity. The series encompass 2-substituted 14-(4-halophenyl)-12-methoxy-14-benzo[]chromeno[3,2-][1,2,4]-triazolo[1,5-]pyrimidines -, 9-benzylideneamino-7-(4-halo-phenyl)-5-methoxy-8-imino-7-benzo-[]chromeno[2,3-]pyrimidines - and 3-ethoxycarbonyl-14-(4-halophenyl)-12-methoxy-14-benzo-[]chromeno[3,2-][1,2,4]triazolo[1,5-]pyrimidine-2-one derivatives -. The structure of these novel compounds were confirmed using IR, ¹H- and C-NMR as well as MS spectroscopy. The new compounds were evaluated in vitro for their antimicrobial activity and it was demonstrated that 7-benzochromenopyrimidine and derivatives of 14-benzochromenotriazolopyrimidine exhibited the most promising antibacterial activities compared to the reference antimicrobial agents. The structure activity relationship (SAR) studies of the target compounds agreed with the in vitro essays and confirmed higher potent antimicrobial activity against some of the tested microorganisms.