反应详情

19.5 g (141 mmol) of potassium carbonate and 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 and then filtered in order to remove the insoluble salts, and concentrated under vacuum. The crude residue obtained is purified by chromatography on silica gel, elution being carried out 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 light oil.

1. filtrationfiltered in order
2. customto remove the insoluble salts
3. concentrationconcentrated under vacuum
4. customThe crude residue obtained
5. customis purified by chromatography on silica gel, elution