反应详情

Trimethylaluminium (2M in toluene, 9.64 ml, 19.28 mmol) was added dropwise to a stirred suspension of 5-[2-(3,5-dimethoxyphenyl)ethyl]-2H-pyrazol-3-amine (1.91 g, 7.71 mmol) and methyl 5-chloropyrazine-2-carboxylate (1.33 g, 7.71 mmol) in anhydrous toluene (38.6 ml) at ambient temperature. The resulting solution was then stirred under nitrogen at ambient temperature for 18 h. The reaction was incomplete so the temperature was increased to 60° C. and the reaction mixture was stirred for a further 3 h. The reaction mixture was quenched with methanol (10 mL) and HCl (2M aqueous solution). The mixture was diluted with EtOAc (100 mL) and water (250 mL) and then acidified with HCl (2N aqueous solution). The organic layer was removed and the aqueous further extracted with EtOAc (2×100 mL). The combined organics were washed with water (200 mL), brine (200 mL) dried over MgSO4 and concentrated under reduced pressure. Upon concentration a precipitate formed. The precipitate was collected by filtration, washed with MeOH (10 mL) and air dried to afford the desired compound (1.88 g, 63%) as a yellow solid, which was used without further purification.

1. temperaturewas increased to 60° C.
2. stirringthe reaction mixture was stirred for a further 3 h
3. customThe reaction mixture was quenched with methanol (10 mL) and HCl (2M aqueous solution)
4. additionThe mixture was diluted with EtOAc (100 mL) and water (250 mL)
5. customThe organic layer was removed
6. extractionthe aqueous further extracted with EtOAc (2×100 mL)
7. washThe combined organics were washed with water (200 mL), brine (200 mL)
8. dry with materialdried over MgSO4
9. concentrationconcentrated under reduced pressure
10. concentrationUpon concentration a precipitate
11. customformed
12. filtrationThe precipitate was collected by filtration
13. washwashed with MeOH (10 mL) and air
14. customdried