Reacción #44295

Ecuación de reacción

2-(2-bromoethoxy)tetrahydro-2H pyran

4-iodopyrazole

Cs2CO3

DMF

→

4-iodo-1-[2-(tetrahydro-pyran-2-yloxy)-ethyl]-1H-pyrazole

Rendimiento 87.1%

Disolventes

water

EtOAc

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.STIRRINGthe reaction was stirred at 70° C. for 16 hours
2. 2
   TemperaturaAfter cooling down
3. 3
   OtroThe organic layer was collected
4. 4
   Extracciónthe aqueous layer was extracted with EtOAc (3×100 mL)
5. 5
   LavadoThe combined organic layers were washed with water (3×100 mL)
6. 6
   Secadodried over Na2SO4
7. 7
   Concentraciónconcentrated
8. 8
   Otroto afford dark brown oil
9. 9
   OtroThe crude product was purified on a silica gel column
10. 10
    Lavadoeluting with ethyl acetate and hexanes

Procedimiento

In a round bottom flask was added 4-iodopyrazole (10.22 g, 52.70 mmol), Cs2CO3 (20.6 g, 63.2 mmol), and anhydrous DMF (100 mL). The suspension was stirred at 23° C. for 5 min. 2-(2-bromoethoxy)tetrahydro-2H pyran (9.95 mL, 63.2 mmol) was added and the reaction was stirred at 70° C. for 16 hours. After cooling down, EtOAc (100 mL) and water (100 mL) was added to the reaction. The organic layer was collected, and the aqueous layer was extracted with EtOAc (3×100 mL). The combined organic layers were washed with water (3×100 mL), dried over Na2SO4, and concentrated to afford dark brown oil. The crude product was purified on a silica gel column eluting with ethyl acetate and hexanes to provide 4-iodo-1-[2-(tetrahydro-pyran-2-yloxy)-ethyl]-1H-pyrazole as yellow oil (14.78 g, 87% yield). 1H NMR (300 MHz, DMSO-d6) δ 7.89 (s, 1H) 7.52 (s, 1H) 4.47-4.56 (m, 1H) 4.25-4.35 (m, 2H) 3.81-3.96 (m, 1H) 3.66-3.75 (m, 1H) 3.45-3.57 (m, J=2.83 Hz, 1H) 3.32-3.40 (m, 1H) 1.34-1.71 (m, 6H).

Fuente