反应详情

19.5 g (141 mmol) of potassium carbonate then 19.5 ml (134 mmol) of dimethyl bromomalonate are added to a solution of 25 g (134 mmol) of tert-butyl piperazine-1-carboxylate in 300 ml of acetonitrile. The reaction medium is stirred at ambient temperature for 24 h then filtered to remove the insoluble salts and concentrated under vacuum. The crude residue obtained is purified by chromatography by silica gel eluted with a 70/30 heptane/ethyl acetate mixture. 41 g (97%) of dimethyl 2-(4-tert-butoxycarbonylpiperazin-1-yl)malonate are obtained in the form of a clear oil.

1. filtrationthen filtered
2. customto remove the insoluble salts
3. concentrationconcentrated under vacuum
4. customThe crude residue obtained
5. customis purified by chromatography by silica gel
6. washeluted with a 70/30 heptane/ethyl acetate mixture