反应详情

A solution of 4-(3-methyl-2-nitrophenyl)-piperazine-1-carboxylic acid tert-butyl ester (10 g, 31 mmol), N,N-dimethylformamide dimethyl acetal (13.2 mL, 100 mmol) and pyrrolidine (4 mL, 50 mmol) in 45 mL of DMF was heated under reflux for 20 h. The mixture was concentrated in vacuo and the residue was partitioned between ethyl acetate and water. The ethyl acetate was dried and evaporated. The residue was hydrogenated in 200 mL of THF containing 2.5 g of 10% Pd-C at 50 psi for 6 h. The mixture was filtered, concentrated in vacuo, and partitioned between ethyl acetate and aqueous HCl. The ethyl acetate was washed with brine, dried and evaporated. Silica gel chromatography (10% ethyl acetate-hexane) afforded 2.5 g of 4-(1H-Indol-7-yl)-piperazine-1-carboxylic acid tert-butyl ester (19) as a white solid, m.p. 150-151° C.

1. temperatureunder reflux for 20 h
2. concentrationThe mixture was concentrated in vacuo
3. customthe residue was partitioned between ethyl acetate and water
4. dry with materialThe ethyl acetate was dried
5. customevaporated
6. filtrationThe mixture was filtered
7. concentrationconcentrated in vacuo
8. custompartitioned between ethyl acetate and aqueous HCl
9. washThe ethyl acetate was washed with brine
10. customdried
11. customevaporated