反应详情

3-Trifluoromethyl-5,6-dihydro-8H-imidazo[1,5-a]pyrazine-1,7-dicarboxylic acid 7-tert-butyl ester 1-methyl ester 27c (1.92 g, 5.5 mmol) was dissolved in 50 mL of methanol under stirring, and 30 mL of 4 N sodium hydroxide was then added to the solution. The reaction mixture was reacted for 30 minutes at room temperature and monitored by thin layer chromatography until the disappearance of the starting materials. The mixture was adjusted to pH 4-5 with 2 N hydrochloric acid, and then extracted with ethyl acetate (100 mL×3). The combined organic phase was dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to obtain the title compound 3-trifluoromethyl-5,6-dihydro-8H-imidazo[1,5-a]pyrazine-1,7-dicarboxylic acid 7-tert-butyl ester 27d (2 g) as a white solid, which was directly used in the next step.

1. customThe reaction mixture was reacted for 30 minutes at room temperature
2. extractionextracted with ethyl acetate (100 mL×3)
3. dry with materialThe combined organic phase was dried over anhydrous magnesium sulfate
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure