Ethylenediamine → HCID 19424597, compound

A 500 mL three-neck flash was charged with 150 mL of dry DMSO and the flask flushed with nitrogen. Two syringes were charged separately with solutions of diethylenetriaminepentaacetic acid dianhydride (2.00 g, 5.60 mmol) in 125 mL of DMSO, and 1,2-diaminoethane (0.336 g, 5,60 mmol) in DMSO/DBN (122 mL/3 mL). The solutions were added simultaneously to the flask at ambient temperature at a rate of 40 mL/hour. After the addition was complete, the reaction mixture was allowed to stir for 48 hours, concentrated under vacuum to 10 mL and 5 mL of water added. This solution, at pH 10.9, was applied to AG1-X8 (100-200 mesh, OAc-) resin, and the column eluted with 0.5N acetic acid to yield 0.71 g (30%) product as a white solid after acetic acid removal and lyophilization.