| Compounds | R | Molecular Formula | MIC µg/mL | % Inhibition |
| 4a | CONH2 | C25H20ClN3O5 | >6.25 | 71 |
| 4b | CSNH2 | C25H20ClN3O4S | >6.25 | 95 |
| 4c | NHCONH2 | C25H21ClN4O5 | >6.25 | 79 |
| 4d | NHCSNH2 | C25H21ClN4O4S | >6.25 | 94 |
| 4e | COCH3 | C26H21ClN2O5 | >6.25 | 55 |
| 4f | COC6H5 | C31H23ClN2O5 | >6.25 | 68 |