Syntheses of 1,5-Benzothiazepines: Part-50: 8-Substituted 2,3/2,5-dihydro-2,4-diaryl-1,5-benzothiazepines as Potential Antimicrobial Agents

Abstract

The syntheses of two novel series of 8-substituted 2,5-dihydro-2,4-bis(2,4-dichlorophenyl)-1,5-benzothiazepines and 8-substituted 2,3-dihydro-2-(2,4-dichlorophenyl)-4-(2-hydroxyphenyl)-1,5-benzothiazepines being reported herein were achieved by the reactions of 5-substituted 2-aminobenzenethiols, the substituents being fluoro, chloro, bromo, methyl, methoxy, ethoxy, with α,β-unsaturated carbonyl compounds. The enolizable ketone, 1,3-bis(2,4-dichlorophenyl)-2-propenone, or 3-(2,4-dichlorophenyl)-1-(2-hydroxyphenyl)-2-propenone, was reacted with the 5-substituted 2-aminobenzenethiols in dry ethanol containing trifluoroacetic acid, to obtain 12 new compounds, 8-substituted 2,3/2,5-dihydro-2,4-diaryl-1,5-benzothiazepines by Michael type condensation reaction. The products were characterized on the basis of micro analytical data and spectral analysis comprising IR, ¹H NMR and mass spectral studies. All the compounds were screened for antimicrobial activity, against the Gram-positive Staphylococcus aureus and Gram-negative bacteria, Enterobacter cloacae and Klebsiella aerogenes with various reference drugs, Vancomycin for Staphylococcus aureus and Enterobacter cloacae, polymyxin B for Klebsiella aerogenes and against the fungus Candida albicans with reference drug fluconazole.