Hydrochloric Acid → 4-Methoxybenzoylacetonitrile

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of acetonitrile (15 g) in DMSO (25 mL) was added methyl p-anisate (25 g) and the mixture was stirred with heating at 60° C. for 1 hour. The reaction mixture was allowed to cool and cold water (100 mL) was added dropwise. The mixture was acidified with hydrochloric acid and the precipitated crystals were collected by filtration. The obtained crystals were extracted with ethyl acetate and the solvent was evaporated under reduced pressure. The residue was recrystallized from ethyl acetate to give 4-methoxybenzoylacetonitrile (21 g) as colorless crystals. To a solution of the obtained crystals in toluene was added hydrazine monohydrate (13 g) and the mixture was heated under reflux for 3 hours. The mixture was cooled and the precipitated crystals were collected by filtration to give 5-amino-3-(4-methoxyphenyl)pyrazole (22 g). Subsequently, the title compound was prepared from methyl butyrate, 2-chlorobenzaldehyde and 5-amino-3-(4-methoxyphenyl)pyrazole in the same manner as in Example 94.

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