反应详情

温度

60 °C

To a solution of 8.0 g (R)-4-carbobenzyloxy-1-(4,5-dichloro-2-nitrophenyl)-piperazine-2-carboxylic acid in 200 mL of acetic acid is added 6.0 g of iron powder. With good stirring, the mixture is heated at 60° C. for 2 hours, followed by concentrated under reduced pressure (1-2 mm, <40° C.) to a gray-black residue. This material was slurried with 400 mL of ethyl acetate and filtered. This process was repeated. The combined ethyl acetate filtrates are washed with 150 mL of 1 N HCl, 200 mL of water (2×), 200 mL of brine and dried over MgSO4. Filtration and concentration of the solvent gave a semi-solid material that is crystallized from ethyl acetate-hexane to afford 5.44 g (76.1%) of title compound as a white solid, mp 136-138° C.

1. concentrationby concentrated under reduced pressure (1-2 mm, <40° C.) to a gray-black residue
2. filtrationfiltered
3. washThe combined ethyl acetate filtrates are washed with 150 mL of 1 N HCl, 200 mL of water (2×), 200 mL of brine
4. dry with materialdried over MgSO4
5. filtrationFiltration and concentration of the solvent
6. customgave a semi-solid material that
7. customis crystallized from ethyl acetate-hexane