[OH:1][CH:2]([CH2:12][NH:13][C:14](=[O:20])[O:15][C:16]([CH3:19])([CH3:18])[CH3:17])[CH2:3][NH:4][C:5](=[O:11])[O:6][C:7]([CH3:10])([CH3:9])[CH3:8].C(N(CC)CC)C.[CH3:28][S:29](Cl)(=[O:31])=[O:30]>C(Cl)Cl>[CH3:28][S:29]([O:1][CH:2]([CH2:12][NH:13][C:14]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:20])[CH2:3][NH:4][C:5]([O:6][C:7]([CH3:10])([CH3:9])[CH3:8])=[O:11])(=[O:31])=[O:30]To a solution of di-tert-butyl (2-hydroxy-1,3-propanediyl)biscarbamate (200 g) in methylene chloride (1.2 L) was added triethylamine (384 ml) under cooling on an ice-water bath and then a solution of methanesulfonyl chloride (64 ml) in methylene chloride (300 ml) was dropwise added at a temperature below 15° C. The mixture was stirred at the same temperature for 1.5 hours and quenched with saturated aqueous sodium hydrogencarbonate solution (200 ml). The organic layer was made acidic (pH=3) with diluted hydrochloric acid, and washed with saturated aqueous sodium hydrogencarbonate solution and brine, and dried over anhydrous magnesium sulfate. Concentration under reduced pressure gave a residue, which was triturated with ethyl acetate (100 ml)—hexane (500 ml) to give 2-[(tert-butoxycarbonyl)amino]-1-{[(tert-butoxycarbonyl)amino]methyl}ethyl methanesulfonate (202 g) as a white solid.
Wird geladen…
