反应详情

To a solution of 6-[4-(2-trifluoromethylbenzoyl)piperazin-1-yl]pyridazine-3-carboxylic acid methyl ester (4.436 g, 11.25 mmol) in tetrahydrofuran (50 mL) and water (25 mL) was added lithium hydroxide monohydrate (2.30 g, 54.81 mmol). The reaction mixture was stirred at ambient temperature for 23 h and the pH of the solution was adjusted to ˜3 with concentrated hydrochloric acid (5.3 mL) at 0° C. The mixture was concentrated. Ethyl acetate (100 mL) was added to the residue and the product was precipitated. The solid was collected by filtration, washed with ethyl acetate and dried in vacuo to afford the title compound (3.60 g). The aqueous layer was extracted with ethyl acetate, dried over Na2SO4 and concentrated to give the second portion of title compound (0.463 g). The total amount of product was 4.063 g (95% yield).

1. concentrationThe mixture was concentrated
2. additionEthyl acetate (100 mL) was added to the residue
3. customthe product was precipitated
4. filtrationThe solid was collected by filtration
5. washwashed with ethyl acetate
6. customdried in vacuo