Syntheses of 1,5-Benzothiazepines: Part XXXVI—Syntheses and Antimicrobial Evaluation of 2-(2-Chlorophenyl)-4-(4-chlorophenyl/2-thienyl)-2,5-dihydro-8-substituted-1,5-benzothiazepines

Abstract

Six 5-substituted-2-aminobenzenethiols have been reacted with 3-(2-chlorophenyl)-1-(4-chlorophenyl)-2-propenone and 3-(2-chlorophenyl)-1-(2-thienyl)-2-propenone in dry ethanol saturated with dry HCl gas, to obtain twelve new compounds, 8-substituted-2-(2-chlorophenyl)-4-(4-chlorophenyl/2-thienyl)-2,5-dihydro-1,5-benzothiazepines in satisfactory yields. The structures of the final products have been assigned by elemental microanalyses data for elements, C, H, and N and by IR, ¹ H NMR, and mass spectroscopies. The synthesized compounds have been evaluated for their relative antimicrobial activity against the gram-positive bacteria, Staphylococcus aureus, gram-negative bacteria, Pseudomonas aeruginosa and the fungus, Candida albicans. The compounds have been found to show little antibacterial activity, but interestingly, showed significant antifungal activity.

Keywords:

• Antifungal
• chlorophenyl
• clentiazem
• diltiazem

The authors gratefully acknowledge the financial assistance provided by the CSIR, New Delhi, and the Sophisticated Analytical Instrument Facility (SAIF), Central Drug Research Institute, Lucknow, for providing the elemental analyses and spectral data. Thanks are also due to Principal, LBS Government PG College, Kotputli, Jaipur, the Head, Department of Chemistry, University of Rajasthan, Jaipur, and Dr. Ramesh Mishra, Department of Microbiology, S.M.S. Medical College, Jaipur, for providing the facility to work.

Notes

^a Zone of Inhibitions is in mm.

^b Values in parentheses represent activity index.

^c Zone of Inhibition of Gatifloxin for S. aureus is 25 mm for 5a–f and 22mm for 5g–l.

^d Zone of Inhibition of Natilmicin for P. aeruginosa is 24 mm.

^e Zone of Inhibition of Fluconazole for C. albicans is 14 mm.

^f Concentration used for the test and reference compounds were 100 μ g/disc.