反应详情

4-(4-Chloro-benzoyl)-piperazine-1-carboxylic acid tert-butyl ester (26 g) was dissolved in CH2Cl2 (350 mL). 4M HCL/Dioxane (150 mL) was added. The mixture was stirred at RT for 4 h. White precipitate was formed. The mixture was concentrated. The white solid was washed with Et2O. After the white solid was treated with 1N NaOH (200 mL) and extracted with Ethyl acetate (3×100 mL), the combined organic phase was dried over Na2SO4 and concentrated to give 17.79 g of desired product (99% yield). 1H-NMR (for HCl salt) (300 MHz, MeOD): δ 2.80-2.90 (m, 4H), 3.20-3.80 (m, 4H), 7.29-7.36 (m, 4H).

1. customWhite precipitate was formed
2. concentrationThe mixture was concentrated
3. washThe white solid was washed with Et2O
4. additionAfter the white solid was treated with 1N NaOH (200 mL)
5. extractionextracted with Ethyl acetate (3×100 mL)
6. dry with materialthe combined organic phase was dried over Na2SO4
7. concentrationconcentrated