Hydrochloric Acid → t-butyl [(1R)-2-chloro-1-(4-iodobenzyl)ethyl]carbamate

Participants

Reaction Steps

25 ml of methanol and 25 ml of tetrahydrofuran were added to 6.2 g (18 mmol) of methyl (2R)-t-butoxycarbonylamino-3-(4-iodophenyl)propionate. 3.44 g (91 mmol) of sodium borohydride was added to the resultant mixture under cooling with ice, and they were stirred for 17 hours. The reaction liquid was slowly poured into 1 N hydrochloric acid. After the extraction with ethyl acetate, the organic layer was successively washed with water, 1 N hydrochloric acid, 1 N sodium hydroxide and saturated aqueous NaCl solution, and then dried over anhydrous magnesium sulfate. The solvent was evaporated. 50 ml of dichloromethane was added to the residue. Then, 5.02 ml (36 mmol) of triethylamine and 3.09 g (27 mmol) of methanesulfonyl chloride were added to the resultant mixture under cooling with ice, and they were stirred for 30 minutes. The temperature was elevated to room temperature, and the mixture was stirred for 15 hours. The reaction liquid was diluted with water. After the extraction with dichloromethane, the organic layer was successively washed with 1 N hydrochloric acid, 1 N sodium hydroxide and saturated aqueous NaCl solution, and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure. 40 ml of dimethylformamide and 3.85 g (91 mmol) of lithium chloride were added to the residue, and they were stirred at 50° C. for 19 hours. The reaction liquid was diluted with water. After the extraction with ethyl acetate, the organic layer was successively washed with water and saturated aqueous NaCl solution. The solvent was evaporated, and the residue was purified by the silica gel column chromatography to obtain the title compound.

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