Synthesis and Structural Features of New Cyclofunctionalized Benzimidazoles

Abstract

The synthesis of new tricyclic derivatives having sulfur-containing six or seven-membered rings fused to the «a» edge of benzimidazole system, is reported.The stereochemical characteristics of thiazino-and thiazepinobenzimidazoles (4-7) are described and comparative NMR data are discussed. The synthetic approach to new benzo-or pyridothiazinobenzimidazole tetracyclic systems (8) is also reported.

A Highly Selective Fluorescent Chemosensor for Zinc Ion and Imaging Application in Living Cells

“…To observe the binding interaction with Zn 2+ in a buffer medium, the binding constant value has been determined from the emission intensity data following the equation , Y = Y 0 + Y lim − Y 0 2 { 1 + C M C L + 1 K a C L − [ ( 1 + C M C L + 1 K a C L ) 2 − 4 C M C L ] 1 / 2 } Y , Y 0 , and Y lim are the recorded fluorescence intensity, fluorescence intensity without the addition of Zn 2+ , and fluorescence at the limiting value, respectively, where C M is the target molecule concentration, C L is the chemosensor 1 concentration, and K a is the association constant. The following equation was used for the nonlinear least-squares analysis to determine the association constant K a (Figure ), and the value of K a was estimated as 3.1 (±0.1) × 10 7 mol −1 L. The estimated value of K a is too high compared with the reported values, and it significantly indicates the strong association of 1 with the zinc ion. This high value is probably due to the formation of a neutral complex of Zn 2+ with a bridging bimetallic N 4 O donor chelating Schiff-base ligand.…”

“…Thus, the development of fluorescent chemosensors for probing Zn 2+ has been an active topic as a result of operational simplicity and high sensitivity. To the best of our knowledge, the 5,6-dihydrobenzo[4,5]imidazo[1,2- c ]quinazoline (DBIQ)-based fluorescent probe for sensing Zn 2+ for cellular imaging in living cells is still unexplored, despite the fact that it exhibits a broad spectrum of biological activities …”

Recent Advances in the Research of 2,3-Diaryl-1,3-thiazolidin-4-one Derivatives as Potent HIV-1 Non-nucleoside Reverse Transcriptase Inhibitors

“…2). It was also evidenced by the extensive structural modifications on TBZ derivatives [15][16][17][18][19][20][21][22][23] (Fig. 3) that specific requirements existed in respect of the determining factors for an optimal anti-HIV potency.…”

A thiazepino[4,5-a]benzimidazole derivative hampers the RNA replication of Eurasian serotypes of foot-and-mouth disease virus

“…This molecule is derived from a class of compounds of which the synthesis and structural features were originally described by Chimirri et al [15]. We were first able to identify in vitro activity of this class of compounds against FMDV during a high-throughput screening of a library of drug-like small molecules [16].…”