1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → Tert-butyl(1r)-2,2-dimethyl-1-((4-((5-methyl-3-oxo-1h-imidazo[1,5-c]imidazol-2(3h)-yl)methyl)-1-piperidinyl)carbonyl)propylcarbamate

Participants

Reaction Steps

To a solution of Boc-D-tert-leucine (0.69 g), HOBt (0.69 g) and WSC (0.86 g) in acetonitrile (20 ml) was added a solution of 5-methyl-2-(4-piperidinylmethyl)-1,2-dihydro-3H-imidazo[1,5-c]imidazol-3-one dihydrochloride (0.91 g) as described above, DBU (0.6 ml) and triethylamine (0.61 ml) in acetonitrile (20 ml), and mixed for 15 hours. The solvent was distilled off under reduced pressure, and the residue was dissolved in dichloromethane. The dichloromethane solution was washed with an aqueous sodium hydrogen carbonate solution and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the residue was purified with basic silica gel column (ethyl acetate/methanol=10/1) to obtain the title compound as colorless powder (1.2 g, 66%).

Provenance & Evidence