Table 1 .
Synthesis of imidazole derivatives 5a–k by the three-component condensation of benzoin (2), aldehyde derivatives 3a–k, and ammonium acetate (4) in the presence of LDH–APS–PEI–DTPA nanocomposite (1).
| |||||
|---|---|---|---|---|---|
| Entry | Catalyst | Conditions | Catalyst loading (mg) | Time (min) | Yield (%) |
| 1 | – | Solvent-Free/RT | – | 360 | – |
| 2 | – | EtOH/RT | – | 360 | – |
| 3 | – | H2O/RT | – | 360 | Trace |
| 4 | – | EtOH/50 °C | – | 360 | Trace |
| 5 | – | EtOH/Reflux | – | 360 | 20 |
| 6 | – | H2O/Reflux | – | 360 | Trace |
| 7 | LDH–APS–PEI–DTPA nanocomposite (1) | EtOH/RT | 5 | 360 | 35 |
| 8 | LDH–APS–PEI–DTPA nanocomposite (1) | EtOH/50 °C | 5 | 300 | 60 |
| 9 | LDH–APS–PEI–DTPA nanocomposite (1) | H2O/Reflux | 5 | 180 | 65 |
| 10 | LDH–APS–PEI–DTPA nanocomposite (1) | EtOH/Reflux | 7 | 60 | 85 |
| 11 | LDH–APS–PEI–DTPA nanocomposite (1) | EtOH/Reflux | 5 | 60 | 98 |
| 12 | LDH–APS–PEI–DTPA nanocomposite (1) | EtOH/Reflux | 3 | 60 | 75 |
Reaction conditions: Benzoin (2, 1 mmol), 4-chlorobenzaldehyde (3b, 1 mmol), ammonium acetate (4, 2.5 mmol), and LDH–APS–PEI–DTPA nanocomposite (1).
RT: room temperature.