Table 23.
Five-component synthesis of dihydropyrano[2,3-c]pyrazoles 88 and their in vitro antibacterial activity against four bacterial strains.
| ||||||
|---|---|---|---|---|---|---|
| Compound | Ar | Yield of 88 (%) | Antibacterial Activity of Compounds 88 (Zone of Inhibition (in mm) at conc. 100 mg/mL after 24 h) | |||
| Gram-Positive Bacteria | Gram-Negative Bacteria | |||||
| BS | SA | EC | PA | |||
| 88a | 4-MeOC6H4 | 81 | -- | -- | -- | -- |
| 88b | 4-MeC6H4 | 85 | 3.8 | 3.0 | 2.9 | 2.6 |
| 88c | 4-HOC6H4 | 84 | 9.1 | 8.8 | 8.7 | 8.0 |
| 88d | Ph | 82 | 4.9 | 4.6 | 4.5 | 4.3 |
| 88e | 4-FC6H4 | 80 | 18.8 | 17.1 | 17.5 | 15.2 |
| 88f | 3-FC6H4 | 83 | 13.6 | 12.2 | 10.9 | 9.6 |
| 88g | 3-HOC6H4 | 84 | 5.6 | 5.1 | 5.6 | 5.6 |
| 88h | 2-HOC6H4 | 86 | 7.5 | 7.4 | 6.3 | 7.0 |
| 88i | 2-MeC6H4 | 83 | -- | 2.8 | -- | -- |
| 88j | 2-MeOC6H4 | 89 | -- | -- | -- | -- |
| 88k | 2-ClC6H4 | 88 | 11.4 | 10.4 | 10.2 | 9.1 |
| 88l | 4-ClC6H4 | 82 | 15.6 | 13.1 | 12.7 | 11.0 |
| 88m | 4-BrC6H4 | 84 | 9.8 | 9.3 | 8.9 | 8.2 |
| 88n | 4-NO2C6H4 | 83 | 16.2 | 15.2 | 15.3 | 13.7 |
| Tetracycline a | -- | -- | 19.4 | 18.1 | 16.8 | 14.2 |
BS (Bacillus subtilis), SA (Staphylococcus aureus), EC (Escherichia coli), PA (Pseudomonas aeruginosa). a Standard drug for this study.