Imidazole → tert-butyl N-(2-iodoethyl)carbamate

Participants

Reaction Steps

Iodine (30.46 g, 0.120 mol) was added in three portions to a solution of triphenylphosphine (28.85 g, 0.110 mol) and imidazole (7.49 g, 0.110 mol) in dichloromethane (654 mL), and the reaction was stirred until the iodine dissolved. A solution of tert-butyl 2-hydroxyethylcarbamate (17.7 g, 0.110 mol) 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 the solution became colorless. The organic layer was washed sequentially with saturated aqueous sodium thiosulfate, water, and brine; dried over magnesium sulfate; filtered; and concentrated under reduced pressure. The resulting pale yellow oil was purified by column chromatography on silica gel (eluting with 80:20 hexanes:ethyl acetate) to provide a pale yellow oil which slowly crystallized to afford 24.6 g of tert-butyl 2-iodoethylcarbamate as a yellow solid.

Provenance & Evidence