反应详情

To an ice-cold, stirred solution of triphosgene (108 mg, 0.36 mmol) and diisopropylethylamine (0.6 mL, 3.3 mmol) in methylene chloride (2.0 mL) was added amino sulfone from step 4 (210 mg, 0.98 mmol) in methylene chloride (3.5 mL) dropwise. After 5 min a solution of dihydrochloride of (2R,3S)-3-amino-4-(3,5-difluorophenyl)-1-[(3-ethylbenzyl)amino]butan-2-ol (401 mg, 0.98 mmol) was added and the reaction mixture was warmed until the solution became homogeneous. The reaction mixture was diluted with methylene chloride, washed with 1 N hydrochloric acid (25 mL), saturated sodium bicarbonate (25 mL), and saturated sodium chloride, dried (magnesium sulfate), filtered, and concentrated under reduced pressure. Purification by flash column chromatography (silica, 15:85 methanol/chloroform) provided a clear solid. The solid was dissolved in methanol (1 mL), and treated with hydrochloric acid (0.3 mL of a 1.0 M solution in diethyl ether, 0.3 mmol). The resulting precipitate was collected by filtration to provide the title compound (38 mg): mp 130-134° C.; APCI MS m/z 538 [M+H]+.

1. temperaturethe reaction mixture was warmed until the solution
2. washwashed with 1 N hydrochloric acid (25 mL), saturated sodium bicarbonate (25 mL), and saturated sodium chloride
3. dry with materialdried (magnesium sulfate)
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customPurification by flash column chromatography (silica, 15:85 methanol/chloroform)
7. customprovided a clear solid
8. filtrationThe resulting precipitate was collected by filtration