Diisopropylethylamine → HCID 56832736, compound

Participants

Reaction Steps

2-Fluoro-5-[(4-oxo-3H-phthalazin-1-yl)methyl]benzoic acid 1a (801 mg, 2.69 mmol) was dissolved in 25 mL of N,N-dimethylformamide, followed by addition of O-(1-benzotriazolyl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (1.27 g, 3.36 mmol), crude 3-(2,2,2-trifluoro ethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine 26b (460 mg, 2.24 mmol) and N, N-diisopropylethylamine (0.8 mL, 4.48 mmol). After stirring for 12 hours, the reaction mixture was concentrated under reduced pressure, added with 30 mL of H2O and extracted with ethyl acetate (30 mL×3). The organic phase was combined, concentrated under reduced pressure, added with 30 mL of ethyl acetate, washed with saturated sodium chloride solution (20 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure and the resulting residue was purified by thin layer chromatography with elution system A to obtain 4-[[4-fluoro-3-[3-(2,2,2-trifluoroethyl)-6,8-dihydro-5H-[1,2,4]triazolo[4,3-a]pyrazine-7-carbonyl]phenyl]methyl]-2H-phthalazin-1-one 26 (240 mg, yield 22.1%) as a white solid.

Provenance & Evidence