A solution of Benzyl (3-aminopropyl)carbamate (5b) (7.57 g, mmol) and tert-butyl acrylate (4.66 g, mmol) in EtOH (abs, 100 mL) was stirred overnight and the solvent was removed in vacuo. The product was purified on a dry column (eluting from heptane, 10% EtOAc) to give 3.82 g (31%) of the product as a colorless oil. 1 4.9.9 Di-t-butyl 3,3'-((2-aminoethyl)azanediyl)dipropionate (4a) A solution of compound 3a 78 mmol) in MeOH (100 mL) was treated with Pd/C (1.59 g, 10%) and H2 at a pressure of 3 bar overnight. The mixture was filtered through a plug of celite on a glass filter funnel with suction and additional fractions of MeOH (3 × 10 mL) was added the filter to wash any residue of product out of the celite. The solvent was removed in vacuo to give 10.04 g (quant.) of the product as a light yellow oil. 1