Synthesis and Characterization of Some Novel 2-(Trifluoromethyl)pyrimido[1,2-a]benzimidazoles and Pyrimido[1,2-a]benzimidazol-2H)-ones of Biological Interest

Abstract

S y n t h e s i s o f S o m e N o v e l P y r i m i d o [ 1 , 2 -a ] b e n z i m i d a z o l e sAbstract: The synthesis of some potentially active 2-(trifluoromethyl)pyrimido[1,2-a]benzimidazoles and pyrimido[1,2-a]benzimidazol-2(1H)-ones by the cyclization of 4-alkoxyvinyl trifluoro(chloro)methyl ketones with 2-aminobenzimidazole is described. The structure of the products was assigned based on 1 H and 13 C NMR as well as 2D-NMR experiments. Some of the obtained products exhibited significant DNA-topoisomerase I inhibitory activity.

Catalyst-free tandem Michael addition-cyclization reactions in aqueous media for the synthesis of benzimidazo[1,2-a]pyrimidinone derivatives

“…Phenyl (1h), phenyl with electron-withdrawing groups (1a-b, 1g) or electron-donating groups (1f) could afford good yields (entries 1-2, 6-8). However, furyl or nitro substituted substrates resulted in relatively low yields due to the decomposition of substrates (1c-e, 1i) through the retro-Morita-Baylis-Hillman reaction under heating conditions (entries [3][4][5]9). Although water and methanol as a cocatalyst could promote the Baylis-Hillman reaction, it is problematic to perform the Baylis-Hillman reaction in aqueous media [25].…”

“…Among them, benzimidazo [1,2-a]pyrimidinone and its derivatives have attracted considerable attention due to their various biological activities [4][5][6]. Although several approaches have been used in the synthesis of benzimidazo [1,2-a]pyrimidinones [6][7][8][9], searching for new types of substrates to enhance the diversity and new synthetic methods to synthesize benzimidazo [1,2-a] pyrimidinone compounds is still required.…”

Electronic spectra and DFT calculations of some pyrimido[1,2-a]benzimidazole derivatives

“…For example, pyrimido[1,2-a]benzimidazoles possess antimicrobial [1][2][3],antimalarial [4], antiproliferative [5], antiamoebic [6] , antineoplastic [7], hypotensive, spasmolytic, antiaggregant [8], anesthetic [9], diuretic [10], antiinflammatory [11][12], antibiotics against staphylococcus and mycobacterium ranae [13]. Other Pyrimidobenzimidazole derivatives have antiarrythmic [13], herbicidal [14], benzodiazepine receptor binding [15], DNA-topoisomerase I inhibitory [16], immunotropic activity [17]. Because of their wide range of biological activities and scientific relevance, the newly synthesized dihydrobenzimidazo [1,2-a]pyrimidine derivatives are expected to have biological potential which needs to be explored by investigating their electronic structure experimentally and theoretically.…”

One‐pot Combinatorial Synthesis of Benzo[4,5]imidazo‐[1,2‐a]thiopyrano[3,4‐d]pyrimidin‐4(3H)‐one Derivatives

“…They play an important role in the field of medicinal chemistry and argrochemistry because of their potential biological activities, such as weed control and antitumor activity. 1,2 Benzo [4,5]imidazo [1,2-a]pyrimidine derivatives can be used as inhibitor of cell proliferation, 3 lymphocyte specific kinase, 4 DNA-topoisomerase and protein kinase. 5,6 The compounds with thiopyran and pyrimidine core unit have important biological activities, such as anti-HIV virus, antibacterial and fungicidal activity, 7 neuroleptic activity.…”