Eco-Friendly Approach for the Synthesis of Thiophene Linked Benzothiazepines as
Biocompatible Free Radical Scavengers
A series of new thiophene tethered benzothiazepines (5a-h) were synthesized through citrus juice mediated (4+3) annulations of thienyl chalcones with 2-aminobenzenethiol in the presence of tetrabutylammonium bromide as phase transfer catalyst under reflux conditions. The synthesized compounds were characterized by spectroscopic and CHN analysis. To check the antioxidant potentials of the synthesized compounds, in vitro DPPH and hydroxyl radical scavenging assays were conducted. The results shows that amongst the series, compounds 5b with (21.44-49.72%) and (16.88-42.60%); 5c with (24.88-56.00%) and (22.33-53.12%); and 5h with (22.80-47.10%) and (15.33-44.12%) excellent DPPH and hydroxyl radical potencies comparable with the respective standards used in the experiments.