5-Chloro-1-methyl-3-(trifluoromethyl)-1H-pyrazole-4-carbaldehyde → 1-methyl-5-(oxetan-3-yloxy)-3-trifluoromethyl-1H-pyrazole-4-carbaldehyde

Participants

Reaction Steps

Oxetane-3-ol (6.12 g, 82.7 mmol) was added dropwise to potassium tert-butoxide (1M in THF) (69.6 ml, 69.6 mmol) at room temperature. 5-Chloro-1-methyl-3-trifluoromethyl-1H-pyrazole-4-carbaldehyde (9.86 g, 46.4 mmol) was dissolved in THF (40 ml) and added slowly to the solution. After 25 minutes the mixture was concentrated and the residue partitioned between ethyl acetate and water. The two phases were separated and the aqueous phase was extracted several times with ethyl acetate. The combined organic phases were washed with brine, dried over magnesium sulfate and concentrated to yield the product as brown oil (11.6 g) which was used in the next step without further purification.

Provenance & Evidence