反应详情

The crude product compound III (˜6.6 mmol) and piperazine (2.3 g, 26 mmol) was dissolved in dry MeCN (50 mL) and heated at reflux 12 h. The solvent was removed in vacuo, the residue dissolved in CH2Cl2 and washed with water and the organic phase dried (K2CO3) and evaporated in vacuo. After chromatography on silica (0-20% MeOH in CH2Cl2, 1% NH4OH), a total of 1.8 g (68%, 2 steps) compound 1 was obtained. Further purification could be achieved by reverse phase chromatograpy (LiChroprep RP-18, 10-50% MeCN in water, 0.1% TFA) to give 1.2 g colorless product. The dihydrochloride salt was made by treatment with 2 eq. HCl in ether.

1. temperatureheated
2. temperatureat reflux 12 h
3. customThe solvent was removed in vacuo
4. dissolutionthe residue dissolved in CH2Cl2
5. washwashed with water
6. dry with materialthe organic phase dried (K2CO3)
7. customevaporated in vacuo