Entry | Solvent (reflux) | Catalyst | Time (min) | Yield (%)a |
---|---|---|---|---|
1 | EtOH | – | 500 | 39 |
2 | EtOH | CAN (7Â mol%) | 250 | 53 |
3 | EtOH | NaHSO4 (5Â mol%) | 300 | 45 |
4 | EtOH | InCl3 (4Â mol%) | 200 | 56 |
5 | EtOH | ZrO2 (6Â mol%) | 250 | 60 |
6 | EtOH | p-TSA (3Â mol%) | 200 | 64 |
7 | EtOH | Nano-Fe3O4 (10Â mg) | 200 | 52 |
8 | EtOH | Cross-PAA-SO3H (10Â mg) | 150 | 56 |
9 | EtOH | nano-Fe3O4 (5 mg) + Cross-PAA-SO3H (5 mg) | 150 | 60 |
10 | H2O | Cross-PAA-SO3H@nano-Fe3O4 (7Â mg) | 150 | 77 |
11 | DMF | Cross-PAA-SO3H@nano-Fe3O4 (7Â mg) | 150 | 82 |
12 | CH3CN | Cross-PAA-SO3H@nano-Fe3O4 (7Â mg) | 150 | 89 |
13 | EtOH | Cross-PAA-SO3H@nano-Fe3O4 (5Â mg) | 150 | 92 |
14 | EtOH | Cross-PAA-SO3H@nano-Fe3O4 (7Â mg) | 150 | 94 |
15 | EtOH | Cross-PAA-SO3H@nano-Fe3O4 (9Â mg) | 150 | 94 |