O-Xylene → 1-(4-Fluorophenyl)-4-oxocyclohexanecarbonitrile

Beteiligte Stoffe

Reaktionsschritte

A mixture of 221 parts of 4-fluorobenzeneacetonitrile, 700 parts of sodium methoxide solution 30% and 900 parts of dimethylbenzene was stirred for 5 minutes. Then there were added dropwise 309 parts of methyl 2-propenoate (exothermic reaction: temperature rose to 65° C.). Upon completion, stirring was continued overnight at reflux temperature. The methanol was distilled off till an internal temperature of 110° C. was reached. After cooling, 1000 parts of a hydrochloric acid solution 6N were added dropwise and the whole was stirred and refluxed for 5 minutes. Upon cooling, the layers were separated. The organic phase was dried, filtered and evaporated. The residue was stirred and refluxed for 4 hours together with 500 parts of acetic acid, 500 parts of water and 500 parts of a hydrochloric acid solution. After cooling, the product was extracted with trichloromethane. The extract was washed successively with water, with a diluted sodium hydroxide solution and again with water till neutralization, dried, filtered and evaporated. The residue was crystallized from 2-propanol, yielding 134.5 parts of 1-(4-fluorophenyl)-4-oxocyclohexanecarbonitrile; mp. 91.8° C. (intermediate 1).

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