反应详情

温度

130 °C

Copper (I) iodide (0.18 g, 0.95 mmol) was added to a suspension of 4,5,6,7-tetrahydro-4-oxo-pyrazolo[1,5-a]pyrazine-2-carboxylic acid ethyl ester (1.0 g, 4.78 mmol), 1-bromo-4-fluorobenzene (1.0 mL, 9.56 mmol), N,N′-dimethylethylenediamine (0.30 mL, 2.86 mmol) and K2CO3 (1.3 g, 9.56 mmol) in toluene (20 mL). The reaction mixture was stirred at 130° C. for 16 hours. The mixture was filtered through a pad of diatomaceous earth which was washed with AcOEt. The mixture was diluted with AcOEt and washed with a 16% aqueous solution of NH4OH. The organic layer was separated, dried (Na2SO4), filtered and the solvents evaporated in vacuo. The crude product was purified by flash column chromatography (silica; AcOEt in DCM 0/100 to 30/70). The desired fractions were collected and the solvents evaporated in vacuo to yield 5-(4-fluorophenyl)-4-oxo-4,5,6,7-tetrahydro-pyrazolo[1,5-a]pyrazine-2-carboxylic acid ethyl ester (1.3 g, 90% yield) as a white solid.

1. filtrationThe mixture was filtered through a pad of diatomaceous earth which
2. washwas washed with AcOEt
3. additionThe mixture was diluted with AcOEt
4. washwashed with a 16% aqueous solution of NH4OH
5. customThe organic layer was separated
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. customthe solvents evaporated in vacuo
9. customThe crude product was purified by flash column chromatography (silica; AcOEt in DCM 0/100 to 30/70)
10. customThe desired fractions were collected
11. customthe solvents evaporated in vacuo