反应详情

To 3-bromo-7-{[2-chloro-3-(trifluoromethyl)phenyl]carbonyl}-5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyrazine (0.150 g, 0.366 mmol, e.g. see Example 1 for methods of preparation) in 1,2-dimethoxyethane (DME) (3 mL) was added aqueous sodium carbonate solution (1.9 mL, 1 M) followed by phenylboronic acid (0.067 g, 0.549 mmol, commercially available e.g. from Sigma-Aldrich or Strem Chemicals) and dichlorobis(triphenylphosphine)palladium(II) (0.013 g, 0.018 mmol). The reaction mixture was heated at reflux for 7 hours. The mixture was diluted with water (10 mL) and extracted with ethyl acetate (twice). The combined organic fractions were dried, filtered and evaporated. An attempt to purify the crude material on silica gel chromatography using methanol in Dichloromethane (0-20%) as eluent was unsuccessful. The residue was then purified using mass-directed automated (preparative) HPLC (MDAP) to give 7-{[2-chloro-3-(trifluoromethyl)phenyl]carbonyl}-3-phenyl-5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyrazine (0.076 g) as a white solid.

1. temperatureThe reaction mixture was heated
2. temperatureat reflux for 7 hours
3. extractionextracted with ethyl acetate (twice)
4. customThe combined organic fractions were dried
5. filtrationfiltered
6. customevaporated
7. customAn attempt to purify the crude material on silica gel chromatography
8. customThe residue was then purified