反应详情

1-Cinnamoyl-4-formylpiperazine (1.22 g) was dissolved in chloroform (8 mL), and the atmosphere was purged with nitrogen. Under stirring of the solution in an ice-water bath, a liquid mixture (concentrated hydrochloric acid:methanol=1:4) (5 mL) was added thereto. The mixture was stirred at room temperature for 20 hours and 30 minutes and in a 60° C.-water bath for one hour. Further, under stirring of the mixture in an ice-water bath, the same liquid mixture as described above (concentrated hydrochloric acid—methanol mixture) (4 mL) was added thereto, and the resultant mixture was stirred in a water bath for 6 hours at 60° C. The solvents were removed under reduced pressure, and water was added to the residue, followed by extraction with ethyl acetate. The ethyl acetate layer was removed, and pH of the water layer was adjusted to 8 to 9 with saturated sodium hydrogencarbonate solution, followed by extraction twice with chloroform. The chloroform layers were combined and dried over sodium sulfate anhydrate. The solvent was removed under reduced pressure, to thereby yield 1.14 g of the product of interest as a colorless oil. The product was employed in the next step in a crude form.

1. customthe atmosphere was purged with nitrogen
2. additiona liquid mixture (concentrated hydrochloric acid:methanol=1:4) (5 mL) was added
3. stirringThe mixture was stirred at room temperature for 20 hours and 30 minutes and in a 60° C.-water bath for one hour
4. stirringFurther, under stirring of the mixture in an ice-water bath
5. additionwas added
6. stirringthe resultant mixture was stirred in a water bath for 6 hours at 60° C
7. customThe solvents were removed under reduced pressure, and water
8. additionwas added to the residue
9. extractionfollowed by extraction with ethyl acetate
10. customThe ethyl acetate layer was removed
11. extractionfollowed by extraction twice with chloroform
12. dry with materialdried over sodium sulfate anhydrate
13. customThe solvent was removed under reduced pressure