Acetone → 4-Benzyl-1,4,7,10-tetraazacyclododecane-2,6-dione

Participants

Reaction Steps

To a solution of 31.2 g dimethyl-N-benzyliminodiacetate in 2.5 l of dry ethanol at reflux under nitrogen was added dropwise 12.8 g of diethylenetriamine in 160 ml of dry ethanol. Reflux was carried out for a total of 137 hours. The solution was evaporated under reduced pressure leaving a yellow paste. Trituration with acetone left 5.2 g of the desired product as a colorless solid. 13C NMR (methanol, ppm vs TMS): 173.130.5, 129.130.5, 129.6, 128.8, 64.0, 46.3, 38.7. Mass spectrum (CI): m/e 291 (M+H) and 289 (M-H).

Provenance & Evidence