200283-08-5

24424-99-5

111-41-1

200283-08-5

The general procedure for the synthesis of tert-butyl (2-((tert-butoxycarbonyl)amino)ethyl)(2-hydroxyethyl)carbamate from di-tert-butyl dicarbonate and hydroxyethyl ethylenediamine was as follows: N-(2-hydroxyethyl)ethylenediamine (2.06 g, commercially available) and triethylamine (13.8 mL) were dissolved in a solvent mixture of ethanol (30 mL) and tetrahydrofuran (30 mL). Subsequently, di-tert-butyl dicarbonate (10.8 g) was added to the reaction mixture and the reaction mixture was stirred at room temperature for 24 hours. Upon completion of the reaction, the reaction mixture was extracted by adding tert-butyl methyl ether (TBME) and 2 M aqueous hydrochloric acid to the reaction mixture. The organic layer was washed sequentially with saturated aqueous sodium bicarbonate and brine and then dried with anhydrous magnesium sulfate. The dried organic layer was concentrated under reduced pressure to give tert-butyl (2-((tert-butoxycarbonyl)amino)ethyl)(2-hydroxyethyl)carbamate as an off-white oil (6.98 g, quantitative yield). Mass spectrum (ESI, m/z): 305.01 [M + H]+; retention time (tR) = 0.73 min.