反应详情

1.01 g of 4-acetyl-1-(2-pyrimidinyl)-5-methylpyrazole was dissolved in 80 ml of anhydrous ethanol. After adding 1.25 g of 1-benzylpiperazine hydrochloride and 0.45 g of paraformaldehyde, the mixture was heated under reflux for 18 hours. Further, 0.60 g of 1-benzylpiperazine hydrochloride and 0.20 g of paraformaldehyde were added and the resulting mixture was heated under reflux for additional 8 hours. After cooling, the crystals were collected by filtration and extracted with chloroform and a saturated aqueous solution of sodium hydrogencarbonate. The extract was washed with a saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. After evaporating the solvent, the residue thus obtained was purified by silica gel column chromatography (50 g, chloroform:methanol=50:1), converted into hydrochloride by adding a 1N hydrochloric acid/ethanol solution and then recrystallized from ethanol. Thus 742 mg of the title compound was obtained.

1. temperaturethe mixture was heated
2. temperatureunder reflux for 18 hours
3. temperaturethe resulting mixture was heated
4. temperatureunder reflux for additional 8 hours
5. temperatureAfter cooling
6. filtrationthe crystals were collected by filtration
7. extractionextracted with chloroform
8. washThe extract was washed with a saturated aqueous solution of sodium chloride
9. dry with materialdried over anhydrous sodium sulfate
10. customAfter evaporating the solvent
11. customthe residue thus obtained
12. customwas purified by silica gel column chromatography (50 g, chloroform:methanol=50:1)
13. additionby adding a 1N hydrochloric acid/ethanol solution
14. customrecrystallized from ethanol