Table 1 Screening experimental data for condensation of 13 and 14
Solvent | Base | Catalyst | Temp (°C) | Time (h) | Reaction yield (%) | Isolated yield (%) | HPLC purity |
|---|---|---|---|---|---|---|---|
Ethanol | TEA | – | 75–78 | 30.0 | 62.5 | 28.25 | 68.00 |
IPA | DIPEA | DBU | 78–80 | 50.0 | 70.2 | 34.28 | 75.00 |
Methanol | DIPEA | DBU | 61–65 | 52.0 | 12.0 | 45.71 | 15.00 |
Toluene | TEA | KI | 108–111 | 31.0 | 11.5 | 48.97 | 15.00 |
MEG | DIPEA | KI | 120–125 | 6.0 | 83.5 | 72.00 | 99.51 |
MEG | DIPEA | – | 120–125 | 5.0 | 85.00 | 67.97 | 99.60 |
MEG | DIPEA | DBU | 120–125 | 5.0 | 85.5 | 77.14 | 99.65 |
MEG | TEA | DBU | 120–125 | 6.0 | 54.0 | 54.29 | 60.00 |
ACN | K2CO3 | – | 80–85 | 30.0 | 25.0 | 60.00 | 30.00 |
DMF | K2CO3 | – | 100–105 | 24.0 | 16.0 | 56.00 | 21.00 |