Pyridine → 2-[(2,4-Dichlorophenyl)methyl]-4,4-dimethylisoxazolidine-3,5-dione

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Seventy-five ml of methylene chloride and 9.6 ml (0.12 mole) of pyridine were placed in a flask under argon and cooled to 0° C. To this solution 8.4 grams (0.05 mole) dimethylmalonylchloride in 20 ml methylene chloride was added dropwise with stirring. This mixture was cooled to -70° C. and 9.6 g (0.05 mole) of N-(2,4-dichlorophenylmethyl)hydroxylamine (Intermediate E) was added in a single portion, and the temperature rose to 35° C. Stirring was continued for two hours at -10° C., and at ambient temperature for about 18 hours. The reaction mixture was washed with 2 N hydrochloric acid and saturated aqueous sodium chloride solution, and the methylene chloride layer was dried over sodium sulfate, which was removed by filtration. The filtrate was evaporated under reduced pressure and the resulting viscous liquid was subjected to column chromatography on silica gel. Elution was accomplished with 25% ethyl acetate in hexane. Cuts 3-11 were combined and solvent was removed under reduced pressure, yielding a light orange viscous liquid. This solidified as 6.5 grams of product (45% yield); mp 68°-69.5° C. The nmr and ir spectra were consistent with the assigned structure.

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