Imidazole → tert-butyl N-(3-iodopropyl)carbamate

Participants

Reaction Steps

Iodine (21.1 g, 83.1 mmol) was added in three portions to a solution of triphenylphosphine (19.83 g, 75.6 mmol) and imidazole (5.15 g, 75.6 mmol) in dichloromethane (300 mL). The resulting reddish-brown solution with a white precipitate was stirred until all of the iodine had dissolved. A solution of tert-butyl 3-hydroxypropylcarbamate (13.25 g, 75.61 mmol) in dichloromethane (150 mL) was added over a period of 45 minutes, and the reaction was stirred for 16 hours at ambient temperature. The reaction mixture was poured into saturated aqueous sodium thiosulfate and stirred until solution became colorless. The organic layer was separated and washed sequentially with saturated aqueous sodium thiosulfate, water, and brine; dried over anhydrous magnesium sulfate; filtered; and concentrated under reduced pressure to a pale yellow oil. The oil was purified by flash column chromatography (eluting with 80:20 hexanes:ethyl acetate) to a pale yellow oil which slowly crystallizes upon standing to afford 16.2 g of tert-butyl 3-iodopropylcarbamate as a yellow solid.

Provenance & Evidence