Table 9. Influence of the Unreacted Starting Material on the Ratio of Byproducts in the Hydrogenation of PPNa.
| composition of byproduct | ||||||
|---|---|---|---|---|---|---|
| no. | hydrogenation of PPN | purity of PPA (%) | PPN (%) | TPPA (%) | BPPA (%) | PPAL (%) |
| 1 | original reaction | 99.8 | 73.0 | 19.8 | 0 | 7.2 |
| 2b | recycling the unreacted PPN | 99.8 | 73.7 | 18.1 | 0 | 8.2 |
a
Conditions: 5.0 g (38.2 mmol) PPN, 1.5 g 10% Pd/C (Selcat Q) catalyst, 250 mL water and 50 mL dichloromethane, 5.27 g NaH2PO4·H2O (38.2 mmol) and 3.82 g conc. H2SO4 (38.2 mmol), 30 °C, 6 bar, reaction time: 7 h.
b
2.70 g (20.6 mmol) unreacted and 2.30 g (17.6 mmol) fresh PPN.