1,5-Benzothiazepine, a versatile pharmacophore: A review

Solid catalysts for multistep reactions: one-pot synthesis of 2,3-dihydro-1,5-benzothiazepines with solid acid and base catalysts

1,5-Benzothiazepines derivatives were obtained first by starting from 1,3-diphenylpropenone derivatives (chalcones) and 2-aminothiophenol by using aluminosilicate solid catalysts. However, diffusional limitations and the strong adsorption of products on the catalyst are deleterious for catalyst activity and life. Then a structured amorphous mesoporous catalyst with large pores and mild acidity that works at higher temperatures allowed us to obtain high conversions (99 %) and selectivities (98 %) of the desired product. A one-pot synthesis of 1,5-benzothiazepines that starts from benzaldehyde, acetophenone, and 2-aminothiophenol with 95 % yield was performed by combining optimized solid base and acid catalysts in batch mode as well as in a continuous-flow reactor system. Much better conversion and selectivity as well as process intensification has been achieved with the structured mesoporous materials by avoiding intermediate and final neutralization and purification steps required in the synthesis reported previously that uses homogeneous catalysts.

Benzo[1,5]thiazepine: Synthesis, Reactions, Spectroscopy, and Applications

This review article deals with synthesis and reactions of benzo[1,5]thiazepines and the related derivatives and their applications, biological activity as well as spectroscopic data. Most of the reported data on the methods of synthesis, chemical reactions, and biological activity of these heterocycles published over the last ten years are reviewed in this paper.

One pot regioselective synthesis of a small library of dibenzo[b,f][1,4]thiazepin-11(10H)-ones via Smiles rearrangement

A facile and efficient method has been developed for the synthesis of a small library of dibenzo[b,f][1,4]thiazepin-11(10H)-ones via Smiles rearrangement. Compounds were obtained in excellent isolated yields (70%-92%) under metal-free conditions. More specifically, this transition metal-free process relates to an environmentally friendly, economical, and efficient method for preparing benzoic-fused seven-membered lactams.

2P2Ichem: focused chemical libraries dedicated to orthosteric modulation of protein–protein interactions

Design of focused chemical libraries dedicated to protein–protein interaction targets.

Evaluation of structurally diverse benzoazepines clubbed with coumarins as Mycobacterium tuberculosis agents

Tuberculosis caused by Mycobacterium tuberculosis remains a leading cause of mortality worldwide into 21st century. In continuation with our anti-tuberculosis research programme, in this work, we have prepared molecularly diverse coumarins clubbed with benzothiazepines as well as its aza-analogues-benzodiazepines by molecular hybridization. The resulting compounds were screened for their M. tuberculosis activity against H(37) Rv strains using microplate alamar blue assay. Among the designed diversity, the compounds 5k, 5n and 5o were found significantly active in primary anti-tuberculosis assay at minimum inhibitory concentration <6.25 μm. Moreover, the IC(50) values of 5k and 5o in level-2 screening were observed as >10 μg/mL and 3.63 μg/mL, respectively. Design and synthesis of more focused library and its three-dimensional quantitative structure activity relationship analysis are underway.

Amidation of aldehydes and alcohols through α-iminonitriles and a sequential oxidative three-component Strecker reaction/thio-Michael addition/alumina-promoted hydrolysis process to access β-mercaptoamides from aldehydes, amines, and thiols

Mild and general alumina-promoted hydrolysis conditions for converting α-iminonitriles into carboxamides have been developed. In combination with the oxidative three-component Strecker reaction, the one-pot direct amidation of aldehydes and alcohols is reported. Subsequently, an Yb(OTf)(3)-catalyzed Michael addition of thiols to α,β-unsaturated α-iminonitriles is reported for the synthesis of β-mercapto-α-iminonitriles. The successful integration of an oxidative Strecker reaction, thio-Michael addition, and neutral-alumina-promoted hydrolysis of β-mercapto-α-iminonitriles into a three-component one-pot process allowed us to develop the direct conversion of amines, aldehydes, and thiols into β-mercaptoamides. All of these procedures were applicable to aromatic and aliphatic amines and aldehydes.

Synthesis and anticonvulsant activity of 8-alkoxy-5,6-dihydro-4H-[1,2,4]triazolo[4,3-a][1]benzazepin-1-one derivatives

A series of novel 8-alkoxy-5,6-dihydro-4H-[1,2,4]triazolo[4,3-a][1]benzazepin-1-one derivatives were synthesized and screened for their anticonvulsant activities by the maximal electroshock (MES) test, subcutaneous pentylenetetrazol (scPTZ) test, and their neurotoxicity was evaluated by the rotarod neurotoxicity test (Tox). The results of these tests demonstrated that 8-heptyloxy-5,6-dihydro-4H-[1,2,4]triazolo[4,3-a][1]benzazepin-1-one (3f) and 8-hexyloxy -5,6-dihydro-4H-[1,2,4]triazolo[4,3-a][1]benzazepin-1-one (3e) were the most promising compounds, with median effective dose (ED(50)) of 17.6 and 17.9 mg/kg, and protective index (PI) of greater than 63.4 and 62.4 in the MES test, respectively. These PI values were higher than the PI value of the prototype antiepileptic drug carbamazepine. The scPTZ test showed that 8-pentyloxy-5,6-dihydro-4H-[1,2,4]triazolo[4,3-a][1]benzazepin-1-one (3d) was the most potent with ED(50) value of 38.0 mg/kg and PI value of greater than 29.4, which is much safer than marketed drug carbamazepine. The possible structure-activity relationship was discussed.

Cytogenetic activity of newly synthesized 1,5-benzodiazepines in normal human lymphocyte cultures

INTRODUCTION

Many different types of benzodiazepine medications exist to treat a wide array of psychological and physical diseases based on dosage and implications. Benzodiazepines are generally considered as safe and effective drugs in short term; however, cognitive impairments and paradoxical effects occasionally occur. Our recent studies have shown that some 1,4-benzodiazepines exhibit cytogenetic activity (alprazolam, diazepam, and lorazepam) in normal human lymphocyte cultures. 1,5-Benzodiazepine derivatives are used in the synthesis of fused ring compounds, to study the chemical structure-pharmacological activity correlation. We synthesized four compounds of this category with small structural differences.

AIM

The aim of this study was to investigate their cytogenetic activity in vitro at doses equivalent to the per os doses of the used 1,4-benzodiazepines. Sister chromatid exchanges (SCEs), proliferation rate index, and mitotic index were evaluated in lymphocytes of peripheral blood cultures from two healthy donors.

RESULTS

Three of the newly synthesized compounds exhibited positive cytogenetic activity (statistically significant reduction of SCEs, p < 0.01, t-test), without showing cytostatic properties.

CONCLUSION

The observed reduction of the lymphocytes' SCEs because of 1,5-benzodiazepines' activity is remarkable and requires further investigation to improve pharmacological effects.

In silico modeling of the specific inhibitory potential of thiophene-2,3-dihydro-1,5-benzothiazepine against BChE in the formation of beta-amyloid plaques associated with Alzheimer's disease

Background

Alzheimer's disease, known to be associated with the gradual loss of memory, is characterized by low concentration of acetylcholine in the hippocampus and cortex part of the brain. Inhibition of acetylcholinesterase has successfully been used as a drug target to treat Alzheimer's disease but drug resistance shown by butyrylcholinesterase remains a matter of concern in treating Alzheimer's disease. Apart from the many other reasons for Alzheimer's disease, its association with the genesis of fibrils by β-amyloid plaques is closely related to the increased activity of butyrylcholinesterase. Although few data are available on the inhibition of butyrylcholinesterase, studies have shown that that butyrylcholinesterase is a genetically validated drug target and its selective inhibition reduces the formation of β-amyloid plaques.

Rationale

We previously reported the inhibition of cholinesterases by 2,3-dihydro-1, 5-benzothiazepines, and considered this class of compounds as promising inhibitors for the cure of Alzheimer's disease. One compound from the same series, when substituted with a hydroxy group at C-3 in ring A and 2-thienyl moiety as ring B, showed greater activity against butyrylcholinesterase than to acetylcholinesterase. To provide insight into the binding mode of this compound (Compound A), molecular docking in combination with molecular dynamics simulation of 5000 ps in an explicit solvent system was carried out for both cholinesterases.

Conclusion

Molecular docking studies revealed that the potential of Compound A to inhibit cholinesterases was attributable to the cumulative effects of strong hydrogen bonds, cationic-π, π-π interactions and hydrophobic interactions. A comparison of the docking results of Compound A against both cholinesterases showed that amino acid residues in different sub-sites were engaged to stabilize the docked complex. The relatively high affinity of Compound A for butyrylcholinesterase was due to the additional hydrophobic interaction between the 2-thiophene moiety of Compound A and Ile69. The involvement of one catalytic triad residue (His438) of butyrylcholinesterase with the 3'-hydroxy group on ring A increases the selectivity of Compound A. C-C bond rotation around ring A also stabilizes and enhances the interaction of Compound A with butyrylcholinesterase. Furthermore, the classical network of hydrogen bonding interactions as formed by the catalytic triad of butyrylcholinesterase is disturbed by Compound A. This study may open a new avenue for structure-based drug design for Alzheimer's disease by considering the 3D-pharmacophoric features of the complex responsible for discriminating these two closely-related cholinesterases.