Ammonium Chloride → 1-acetyl-3-trifluoromethyl-5,6-dihydro-8H-imidazo[1,5-a]pyrazine-7-carboxylic acid tert-butyl ester

Participants

Reaction Steps

1-(Methoxy-methyl-carbamoyl)-3-trifluoromethyl-5,6-dihydro-8H-imidazo[1,5-a]pyrazine-7-carboxylic acid tert-butyl ester 27e (0.3 g, 0.79 mmol) was dissolved in 20 mL of tetrahydrofuran under stirring, and methylmagnesium bromide (1.13 mL, 1.58 mmol) was then added dropwise to the solution at 0° C. The reaction mixture was reacted at 0° C. for 1.5 hours and monitored by thin layer chromatography until the disappearance of the starting materials. 50 mL of saturated ammonium chloride and 10 mL of saturated brine were added to the reaction mixture. The mixture was extracted with ethyl acetate (50 mL×3). The combined organic phase was dried with anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography to obtain the title compound 1-acetyl-3-trifluoromethyl-5,6-dihydro-8H-imidazo[1,5-a]pyrazine-7-carboxylic acid tert-butyl ester 27f (0.24 g, yield 90%) as a yellow oil.

Provenance & Evidence