Table 1.
Synthesis of benzyl isocyanate.a
| entry | solvent | reaction conditions | conversionb(%) | yieldb(%) |
| 1 | toluene | 90 °C, MW, CO2 (14.5 bar) | >99 | 75 |
| 2 | toluene | 70 °C, MW, CO2 (14.5 bar) | 96 | 84 |
| 6 | toluene | 50 °C, MW, CO2 (14.5 bar) | 82 | 78 |
| 3 | THF | 70 °C, MW, CO2 (14.5 bar) | 50 | 25 |
| 4 | DMF | 70 °C, MW, CO2 (14.5 bar) | 95 | 80 |
| 5 | MeCN | 70 °C, MW, CO2 (14.5 bar) | >99 | 85 |
| 7 | MeCN | 50 °C, MW, CO2 (14.5 bar) | >99 | 94 |
| 8c | MeCN | 50 °C, CO2 (1 bar) | 41 | 25 |
| 9 | MeCN | rt, CO2 (1 bar) | 25 (95)d | 21 (85)d |
| 10e | MeCN | 50 °C, CO2 (14 bar) | 93 | 89 |
aUnless otherwise stated, reactions were performed in the presence of PS-PPh2 (5 equiv), reaction time 4 h. bDetermined by GC–MS. cThe reaction was performed in an oil bath. dReaction time 24 h. eThe reaction was performed in a Parr reactor.