反应详情

3-bromopyridin-4-amine (5 g, 28.90 mmol) was suspended in dry toluene (100 mL) and cooled in an ice-bath. A solution of thiophosgene (6.646 g, 4.407 mL, 57.80 mmol) in dry toluene (100 mL) was added dropwise over 25 mins. The resulting orange/red suspension was stirred at reflux overnight. The red suspension was allowed to cool to RT and concentrated under reduced pressure to give a dark brown/red solid. This material was partitioned between saturated NaHCO3 and DCM. The aqueous layer was extracted with further DCM (3×50 mL) and the combined organics were dried over Na2SO4, filtered and concentrated under reduced pressure to give a dark red solid/gum. This material was suspended in MeOH/DCM, adsorbed onto silica under reduced pressure and purified by column chromatography (75% EtOAc in hexanes, ˜300 mL silica) to give 3-bromo-4-isothiocyanatopyridine as a red oil which solidified on standing (3.513 g, 57% Yield). MS (ES+) 216.9.

1. temperaturecooled in an ice-bath
2. temperatureat reflux overnight
3. concentrationconcentrated under reduced pressure
4. customto give a dark brown/red solid
5. customThis material was partitioned between saturated NaHCO3 and DCM
6. extractionThe aqueous layer was extracted with further DCM (3×50 mL)
7. dry with materialthe combined organics were dried over Na2SO4
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure
10. customto give a dark red solid/gum
11. custompurified by column chromatography (75% EtOAc in hexanes, ˜300 mL silica)