反应详情

To a solution of diphosgene (4.1 mL, 34.1 mmol) in EtOAc (40 mL) at 0° C. was added a solution of the 4-iodo-2-nitroaniline (45.5 mmol) in EtOAc (200-500 mL), and the mixture was heated to reflux for 18 h. The solvent was removed in vacuum to leave a brown solid, which was triturated with hot hexane (200 mL). The solid material was filtered off and the filtrate was concentrated under reduced pressure to leave the pure 4-iodo-2-nitrophenylisocyanate as a yellow solid. This material was refluxed in a mixture of excess tert.-BuOH in CH2Cl2 for 2.5 h. Removal of the solvent left an orange solid which was purified by silica gel column chromatography with hexane/EtOAc to give the (4-iodo-2-nitro-phenyl)-carbamic acid tert.-butyl ester as a yellow solid.

1. temperaturethe mixture was heated
2. temperatureto reflux for 18 h
3. customThe solvent was removed in vacuum
4. customto leave a brown solid, which
5. customwas triturated with hot hexane (200 mL)
6. filtrationThe solid material was filtered off
7. concentrationthe filtrate was concentrated under reduced pressure