Table 1 Comparison of yields of 4d through methods with or without microwave irradiation
Entry | Solvent | Method | Time (min) | Temperature/°C | Yield/ % |
|---|---|---|---|---|---|
1 | EtOH | No-MW | 300 | r.t. | 90 |
2 | EtOH | No-MW | 120 | Reflux | 85 |
3 | EtOH | MW | 1 | 78 | 68 |
4 | EtOH | MW | 5 | 78 | 80 |
5 | EtOH | MW | 10 | 78 | 92 |
6 | EtOH | MW | 15 | 78 | 92 |
7 | EtOH | MW | 10 | 70 | 78 |
8 | EtOH | MW | 10 | 85 | 91 |