Reaction #51597

Reaction equation

2,4,6-trifluoropyridine

5-hydroxy-1-methyl-3-trifluoromethylpyrazole

potassium carbonate

→

colorless crystals

Yield 93.0%

2,4,6-Tris(1-methyl-3-trifluoromethylpyrazol-5-yloxy)pyridine

Yield 93.0%

Solvents

sulfolane

pentane ethyl acetate

isopropyl ether

Conditions

Workup

1. 1
   TemperatureAfter cooling
2. 2
   Filtrationfiltered through a bed of silica gel
3. 3
   WashThe filtrate is washed 10 times with water
4. 4
   Dryingthe organic layer is dried over magnesium sulfate
5. 5
   OtherAfter removal of the solvents

Procedure

A mixture of 4.8 g (36 mmol) 2,4,6-trifluoropyridine, 19.8 g (119 mmol) 5-hydroxy-1-methyl-3-trifluoromethylpyrazole and 18.1 g (131 mmol) potassium carbonate in 25 ml anhydrous sulfolane is stirred and heated to 80° C. over a period of 3 days. After cooling, the mixture is diluted with pentane/ethyl acetate (by volume ration 1/1) and filtered through a bed of silica gel. The filtrate is washed 10 times with water and the organic layer is dried over magnesium sulfate. After removal of the solvents, the residue is washed with isopropyl ether and 19.1 g (93% yield) colorless crystals of melting point 130° C. are obtained.

Source