反应详情

To a suspension of 2-(4-{2-[2-(acetylamino)-1,3-thiazol-4-yl]ethyl}phenyl)ethyl tert-butyl hydrazine-1,2-dicarboxylate (620.0 mg, 1.382 mmol) in anhydrous dichloromethane (6.9 ml) was added 4M hydrogen chloride dioxane solution (6.9 ml, 27.6 mmol). After stirring at room temperature for 13 hr, the reaction mixture was concentrated under reduced pressure. Dichloromethane was added to the residue, and the mixture was concentrated again under reduced pressure. The operation was performed twice. Ethyl acetate was further added to the residue, and the mixture was concentrated under reduced pressure. This operation was performed 3 times to remove hydrogen chloride gas azeotropically. The residue was dried under reduced pressure to give a crude product (570.4 mg). The crude product was dissolved in methanol (18 ml) and ethyl acetate (144 ml) was added to recrystallize the crude product. The crystals were collected by filtration, washed with ethyl acetate, and dried under reduced pressure to give the title compound (474.8 mg, 1.234 mmol, yield 89.3%) as a white solid.

1. concentrationthe reaction mixture was concentrated under reduced pressure
2. additionDichloromethane was added to the residue
3. concentrationthe mixture was concentrated again under reduced pressure
4. additionEthyl acetate was further added to the residue
5. concentrationthe mixture was concentrated under reduced pressure
6. customto remove hydrogen chloride gas azeotropically
7. customThe residue was dried under reduced pressure
8. customto give a crude product (570.4 mg)
9. customto recrystallize the crude product
10. filtrationThe crystals were collected by filtration
11. washwashed with ethyl acetate
12. customdried under reduced pressure