Water → 3-Fluoro-4-formylbenzonitrile

Beteiligte Stoffe

Reaktionsschritte

The reaction was carried out under argon. 3-Fluoro-4-methylbenzonitrile (121 g, 895 mmol) and N,N-dimethylformamide dimethyl acetal (245 g, 2.06 mol) were dissolved in DMF (1.8 liters) and stirred under reflux overnight. The contents of the flask was then poured into water (2 liters), the mixture was extracted twice with ethyl acetate and the combined organic phases were washed with saturated sodium chloride solution. The organic phase was concentrated, and the residue was dissolved again in THF/water (1:1, 2.7 liters). Sodium periodate (503 g, 2.35 mol) was added, and the mixture was stirred at room temperature for one hour. The precipitate was then separated off, and the filtrate was recovered and extracted repeatedly with ethyl acetate. The combined organic phases were washed once with saturated sodium bicarbonate solution and once with saturated sodium chloride solution, dried and concentrated to give an oil. This was purified by column chromatography on silica gel (mobile phase: petroleum ether/dichloromethane 6:4, then 4:6, finally pure dichloromethane). The product fractions were concentrated. This gave 28.0 g (20% of theory) of the target compound as a white crystalline solid.

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