Trifluoroacetic acid → HCID 22122234, compound

Participants

Reaction Steps

In 16.5 ml of anisole was dissolved 8.25 g of 4-[3-(4-benzyloxycarbonylamidinophenoxy)propyl]-1-(2,4-dimethoxybenzyl)-2,3-dioxopiperazine, and 33 ml of trifluoroacetic acid was added to the solution, followed by refluxing for 5 hours. After cooling, the solvent was distilled off under reduced pressure. To the resulting residue was added 40 ml of ethyl acetate, and stirred for 30 minutes, after which the precipitate was collected by filtration and dried to obtain 8.23 g of 4-[3-(4-amidinophenoxy)propyl]-2,3-dioxopiperazine trifluoro-acetate. Then, the compound obtained was dissolved in a mixed solvent of 182 ml of dioxane and 82 ml of water, followed by adding thereto 8.37 g of sodium carbonate and 3.62 g of di-tert-butyl dicarbonate, and the resulting mixture was stirred at room temperature for 5 hours. The solvent was distilled off under reduced pressure and 80 ml of ethyl acetate and 80 ml of water were added to the resulting residue and stirred for 30 minutes. The crystals precipitated were collected by filtration and dried to obtain 4.27 g of 1-[3-(4-tert-butoxycarbonyl-amidinophenoxy)propyl]-2,3-dioxopiperazine as colorless crystals.

Provenance & Evidence