反应详情

Compound M (4.12 g) obtained in Reference Example 3 was dissolved in DMF (150 ml), 1-hydroxybenzotriazole monohydrate (5.8 g) and N-ethyl-N-′3-dimethylaminopropylcarbodiimide monohydrochloride (8.2 g) were added thereto, and the mixture was stirred at room temperature for 10 minutes. The mixture was dropwise added to a solution of piperazine (18.6 g) in DMF (300 ml) and the mixture was stirred at room temperature for 12 hours. The solvent was distilled off under reduced pressure and the residue was extracted with chloroform. The extract was washed a saturated aqueous sodium chloride solution and dried over sodium sulfate, and the solvent was distilled off. The resulting residue was suspended in ethanol and the precipitated crystals were collected by filtration to give the desired compound (3.54 g, 73%) as colorless crystals.

1. stirringthe mixture was stirred at room temperature for 12 hours
2. distillationThe solvent was distilled off under reduced pressure
3. extractionthe residue was extracted with chloroform
4. washThe extract was washed a saturated aqueous sodium chloride solution
5. dry with materialdried over sodium sulfate
6. distillationthe solvent was distilled off
7. filtrationthe precipitated crystals were collected by filtration