Iodine → tert-Butyl (4-chloro-3-iodopyridin-2-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

tert-Butyl (4-chloropyridin-2-yl)carbamate (10 g, 43.7 mmol) and tetramethylethylenediamine (12 mL) in anhydrous tetrahydrofuran (200 mL) was cooled to −70° C. and treated dropwise with a solution of 2.5M n-butyllithium (52 mL, 131 mmol) in hexane over a period of 30 minutes. The mixture was stirred at −70° C. for 1 hour and treated dropwise with a solution of iodine (27 g, 109 mmol) in anhydrous tetrahydrofuran at −70° C. After the addition, the mixture was stirred at the −70° C. for 30 minutes and was allowed to warm to room temperature. The mixture was treated with saturated sodium hydrogensulfite solution (200 mL) and stirred for 30 minutes. The mixture was extracted with ethyl acetate (100×3 mL) and the organic layer was washed with water and brine solution (200 mL each) and dried over anhydrous sodium sulfate. Filtration and concentration under vacuum and recrystallization with ethyl acetate-hexane afforded the title compound. LCMS: 298.9 (M+H—NCOOH)+.

Provenance & Evidence