反应详情

To a solution of 13 g. of 4-carbobenzoxy-1-(o-nitrophenyl)piperazine-2-carboxylic acid and 11.0 g. of sodium hydroxide in 200 ml. of water is added a solution of 20 g. of sodium hydrosulfite in 200 ml. of H2O. The orange solution gradually turns colorless over a period of 2-3 hours. Dilute hydrochloric acid is added to bring the pH of the solution to about 3. A white precipitate forms. Stirring is continued for about 3-5 minutes, and the pH is raised to about 7 by the addition of 40% sodium hydroxide. Filtration gives 8.6 g. of product, m.p. 125°-140°. The analytical sample on recrystallization from ethyl acetate hexane gave a m.p. 167°-170°.

1. waitis continued for about 3-5 minutes
2. filtrationFiltration
3. customgives 8.6 g
4. customThe analytical sample on recrystallization from ethyl acetate hexane
5. customgave a m.p. 167°-170°