Dimethylformamide → 5-Chloro-3-(4-methoxy-3-methylphenyl)-1-methyl-1H-pyrazole-4-carboxaldehyde

Participants

Reaction Steps

At 0° C., to phosphorus oxychloride 56 g was added N,N-dimethylformamide 4.0 g and the resulting mixture was stirred for a half hour. Thereto was added 5-hydroxy-3-(4-methoxy-3-methyl-phenyl)-1-methyl-1H-pyrazole (described in Reference preparation example 90) 9.3 g. The resulting mixture was stirred for seven hours and the reaction solvent was distilled off under reduced pressure. To the reaction mixture was added ice water 100 ml and the resulting mixture was extracted with ethyl acetate. The organic layer was washed with water and was dried over anhydrous magnesium sulfate, and was then concentrated under reduced pressure. The resulting residue was subjected to a silica gel column chromatography to give 5-chloro-4-formyl-3-(4-methoxy-3-methyl-phenyl)-1-methyl-1H-pyrazole 6.3 g.

Provenance & Evidence