Triethylamine → N,N'-di-Boc-2-methanesulfonyloxy-1,3-diaminopropane

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Reaction Steps

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.

Provenance & Evidence