Reaction #1716958

Reaction equation

5-bromo-1,1,1-trifluoropentane

hexane

4-iodo-1H-pyrazole

sodium hydride

→

desired product

Yield 83.3%

4-Iodo-1-(5,5,5-trifluoropentyl)-1H-pyrazole

Yield 83.3%

Solvents

water

ether

DMF

Conditions

Workup

1. 1
   WashThe organic layer was washed with H2O
2. 2
   Dryingdried over MgSO4
3. 3
   Filtrationfiltered
4. 4
   Concentrationconcentrated in vacuo
5. 5
   OtherThe crude product was purified by silica gel chromatography (24 g silica gel, eluted with 0-60% EtOAc in hexanes)

Procedure

To a stirred solution of 4-iodo-1H-pyrazole (337 mg, 1.737 mmol) in DMF (10 mL) was added sodium hydride (104 mg, 2.61 mmol). After 30 min, 5-bromo-1,1,1-trifluoropentane (427 mg, 2.085 mmol) was added. The reaction was stirred at rt for 2 h. 3:1 hexane:ether and water were added. The organic layer was washed with H2O, dried over MgSO4, filtered and concentrated in vacuo. The crude product was purified by silica gel chromatography (24 g silica gel, eluted with 0-60% EtOAc in hexanes) to give the desired product (460 mg, 83%) as clear oil. LCMS Anal. Calc'd for C8H10F3IN2 318.0, found [M+H] 319.0. 1H NMR (400 MHz, CDCl3) δ 7.49 (s, 1H), 7.40 (s, 1H), 4.12 (t, J=6.9 Hz, 2H), 2.00-2.15 (m, 2H), 1.85-1.96 (m, 2H), 1.47-1.61 (m, 2H).

Source