Ethanol → HCID 54094027, compound

Temperature

0 °C

(2S)-5-(Acetylamino)-2-(tert-butoxycarbonylamino)hexanoic acid (purchased at Bachem, 5.0 g, 17.34 mmol) and 1-hydroxybenzotriazole hydrate (2.65 g, 17.34 mmol) were subsequently dissolved in dichloromethane (40 ml) and N,N-dimethylformamide (20 ml). The solution was cooled to 0° C. N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (3.32 g, 17.34 mmol) was added. The reaction mixture was stirred at 0° C. for 20 min. A 8.0 M solution of methylamine in ethanol (13 ml, 104 mmol) was added. The reaction mixture was stirred for 16 h, while it was warming up to room temperature. It was diluted with ethyl acetate (300 ml) and washed with a 10% aqueous solution of sodium hydrogensulfate (300 ml). The aquoeus phase was extracted with ethyl acetate (2×150 ml). The combined organic layers were washed with a saturated aqueous solution of sodium hydrogen carbonate (300 ml) and dried over magnesium sulfate. The solvent was removed in vacuo. The crude product was purified by flash chromatography on silica (65 g), using dichloromethane/methanol (10:1) as eluent to give 792 mg of ((1S)-5-(acetylamino)-1-(methylcarbamoyl)pentyl)carbamic acid tert-butyl ester.

1. stirringThe reaction mixture was stirred for 16 h, while it
2. temperaturewas warming up to room temperature
3. washwashed with a 10% aqueous solution of sodium hydrogensulfate (300 ml)
4. extractionThe aquoeus phase was extracted with ethyl acetate (2×150 ml)
5. washThe combined organic layers were washed with a saturated aqueous solution of sodium hydrogen carbonate (300 ml)
6. dry with materialdried over magnesium sulfate
7. customThe solvent was removed in vacuo
8. customThe crude product was purified by flash chromatography on silica (65 g)

ORD record

ord-c99798ddd710424488c2390176bd4491

Source dataset

uspto-grants-2000_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06127341