To a solution of tert-butyl 2-aminoethylcarbamate (4.81 g) in dehydrated chloroform (10 ml) were added sodium carbonate (1.06 g) and N-(2-bromoethyl)tritylamine (3.66 g), and the mixture was stirred under reflux for 3 hours. To the reaction mixture were added diethyl ether and hexane, and the solution was washed with water. The mixture was extracted with 5% aqueous citric acid solution, and the aqueous layer was washed with diethyl ether. The aqueous layer was then made alkaline with sodium hydrogencarbonate followed by extraction with diethyl ether. The organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to give tert-butyl 2-{[2-(tritylamino)ethyl]amino}ethylcarbamate (1.86 g) as a viscous oil.
