تفاعل #44295

معادلة التفاعل

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

4-iodopyrazole

Cs2CO3

DMF

→

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

المردود 87.1%

المذيبات

water

EtOAc

ظروف التفاعل

المعالجة

1. 1
   workup.STIRRINGthe reaction was stirred at 70° C. for 16 hours
2. 2
   درجة الحرارةAfter cooling down
3. 3
   أخرىThe organic layer was collected
4. 4
   استخلاصthe aqueous layer was extracted with EtOAc (3×100 mL)
5. 5
   غسيلThe combined organic layers were washed with water (3×100 mL)
6. 6
   تجفيفdried over Na2SO4
7. 7
   تركيزconcentrated
8. 8
   أخرىto afford dark brown oil
9. 9
   أخرىThe crude product was purified on a silica gel column
10. 10
    غسيلeluting with ethyl acetate and hexanes

الإجراء التجريبي

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).

المصدر