4-Chlorobenzaldehyde → (4-Chlorophenyl)[3-chloro-5-(trifluoromethyl)-2-pyridinyl]methanone

With stirring, 21.6 g of 2,3-dichloro-5-trifluoromethylpyridine, 14.1 g of 4-chlorobenzaldehyde and 2.24 g of 1,3-dimethylimidazolium iodide were added in succession to a suspension of 3.0 g of sodium hydride (80% by weight suspension in mineral oil) in 100 ml of anhydrous dioxane. The mixture was then stirred (under a nitrogen atmosphere) for 11 hours at 50° C. and then for 60 hours at 22° C. The reaction mixture was diluted with 200 ml of water and most of the dioxane was distilled off under reduced pressure. The product was extracted from the residue with methylene chloride (three times 100 ml). The combined organic phases were washed with 50 ml of water, dried over sodium sulfate and finally concentrated. Distillation of the residue at 0.65 mbar (boiling range: 126-139° C.) gave 22.4 g of a colorless oil. Yield: 70% (purity: about 95%); 1H-NMR see Ex. 7.

1. stirringThe mixture was then stirred (under a nitrogen atmosphere) for 11 hours at 50° C.
2. distillationwas distilled off under reduced pressure
3. extractionThe product was extracted from the residue with methylene chloride (three times 100 ml)
4. washThe combined organic phases were washed with 50 ml of water
5. dry with materialdried over sodium sulfate
6. concentrationfinally concentrated
7. distillationDistillation of the residue at 0.65 mbar (boiling range: 126-139° C.)

ORD-Eintrag

ord-d326953d2b9c4a29915a3f725455ab2e

Quelldatensatz

uspto-grants-2002_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06337305B1