Table 1 Effect of different amounts of catalyst, temperature and solvent (5.0 mL) in the synthesis dicyanomethylene pyridine.
| |||||
|---|---|---|---|---|---|
Entry | Solvent (5 mL) | Cat. (mg) | Temp. (˚C) | Time (min) | Isolated yield (%) |
1 | DMF | 10 | 100 | 120 | 38 |
2 | EtOH | 10 | Reflux | 120 | 60 |
3 | CH2Cl2 | 10 | Reflux | 120 | 63 |
4 | CHCl3 | 10 | Reflux | 120 | 20 |
5 | EtOAc | 10 | Reflux | 120 | 40 |
6 | CH3CN | 10 | Reflux | 120 | 58 |
7 | PEG | 10 | Reflux | 120 | 35 |
8 | n-Hexane | 10 | Reflux | 120 | 65 |
9 | H2O | 10 | Reflux | 120 | 52 |
10 | – | 10 | 100 | 20 | 87 |
11 | – | 5 | 100 | 30 | 75 |
12 | – | 15 | 100 | 30 | 87 |
13 | – | 20 | 100 | 30 | 85 |
14 | – | 10 | 25 | 120 | 15 |
15 | – | 10 | 50 | 120 | 68 |
16 | – | – | 75 | 120 | 10 |
17 | – | 10 | 100 | 120 | 70 |
