Two series of new 8-substituted-4-(4-tert-butylphenyl)-2,3-dihydro-1,5-benzothiazepine-2-carboxylic
acids and 8-substituted-4-(4-acetamidophenyl)-2,3-dihydro-1,5-benzothiazepine-2-carboxylic acids
have been synthesized by Michael condensation of 5-substituted-2-aminobenzenethiols with β-(4-
tert-butylbenzoyl) acrylic acid or β-(4-acetamidobenzoyl) acrylic acid, in ethanol in acidic medium in
a single step, in 58-64 % yield. The structures of the newly synthesized compounds were confirmed
by their IR, 1H NMR and mass spectral analyses and micro analytical data. They were screened for
antimicrobial activity, against the Gram-positive bacteria, Staphylococcus aureus, Gram-negative
bacteria, Enterobacter cloacae and Escherichia coli, with respective reference compounds, vancomycin,
polymyxin B, colistin-polymyxin B and against the fungus, Candida albicans with reference drug
fluconazole. Most of the compounds showed activity against Staphylococcus aureus, Enterobacter
cloacae and fungus Candida albicans, while none of the compounds showed activity against Escherichia
coli.