Table 3. Scaling Up of Cu-Catalyzed Nitrobenzene Reduction in EG under Continuous Flow.
| en.a | CuNPs/Celite (w/w %) | flow rate (mL/min) | resid. time (min) | anilineb | nitrobenzeneb | azobenzeneb | azoxybenzeneb |
|---|---|---|---|---|---|---|---|
| 1 | 1.1 g (5% w/w) | 0.132 | 7.2 | >99 | - | - | - |
| 0.22 | 4.3 | 98.1 | 1.3 | - | 0.6 | ||
| 0.308 | 3.1 | 66.6 | 32.7 | - | 0.7 | ||
| 0.440 | 2.2 | 52.9 | 45.7 | - | 1.4 | ||
| 2 | 2.5 g (5% w/w) | 0.3 | 6.8 | >99 | - | - | - |
| 0.5 | 4.1 | >99 | - | - | - | ||
| 0.75 | 2.7 | 73 | 24.7 | - | 2.3 | ||
| 1.0 | 2.0 | 39.6 | 51.9 | 1.5 | 6.8 | ||
| 3 | 5 g (5% w/w) | 0.600 | 7.0 | >99 | - | - | - |
| 1.0 | 4.2 | 98.3 (97%)c | 1 | - | 0.7 | ||
| 1.4 | 3.0 | 67 | 30.2 | - | 2.8 |
a
Reaction performed using a 0.5 M solution of nitrobenzene in EG, KOH 2 eq. Reaction temperature: 130 °C.
b
Reaction yield determined by GC-MS.
c
Reaction was performed in the presence of reused EG.