Syntheses of 1,5-Benzothiazepines. Part 20. Syntheses of 8-Substituted-2,5-dihydro-2-(4-N-dimethylaminophenyl)-4-(4-methoxyphenyl)-1,5-benzothiazepines

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.

Screening of biological activities of a series of chalcone derivatives against human pathogenic microorganisms

In an effort to develop new antimicrobial agents, a series of chalcone derivatives, 3-60, were prepared by Claisen-Schmidt condensation of appropriate acetophenones and 2-furyl methyl ketones with appropriate aromatic aldehydes, furfural, and thiophene-2-carbaldehyde in an aqueous solution of NaOH and EtOH at room temperature. The synthesized compounds were characterized by means of their IR- and NMR-spectral data, and elemental analysis. All compounds were tested for their antibacterial and antifungal activities by the disc diffusion method. For the most active compounds, also minimum inhibitory concentrations (MICs) were determined.

Synthesis of 1,5-benzothiazepines with Microwave Irradiation under Solvent and Catalyst-free Conditions

Microwave irradiation of α,β-p-unsaturated ketones (chalcones) and o-aminothiophenol in the absence of solvent and catalyst provides a highly efficient methodology for the synthesis of 1,5-benzothiazepines in moderate to good yields.