Реакция #44295

Уравнение реакции

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

4-iodopyrazole

Cs2CO3

DMF

→

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

Выход 87.1%

Растворители

water

EtOAc

Условия реакции

Обработка

1. 1
   workup.STIRRINGthe reaction was stirred at 70° C. for 16 hours
2. 2
   ТемператураAfter cooling down
3. 3
   ДругоеThe organic layer was collected
4. 4
   Экстракцияthe aqueous layer was extracted with EtOAc (3×100 mL)
5. 5
   ПромывкаThe combined organic layers were washed with water (3×100 mL)
6. 6
   Сушкаdried over Na2SO4
7. 7
   Концентрированиеconcentrated
8. 8
   Другоеto afford dark brown oil
9. 9
   ДругоеThe crude product was purified on a silica gel column
10. 10
    Промывкаeluting with ethyl acetate and hexanes

Методика

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).

Источник