| 摘要 |
Aromatic/aliphatic nitriles having the formula: Ar-A-CN (I) wherein Ar is phenyl or substituted phenyl and A is a direct chemical bond or a hydrocarbon having from 1 to 6 carbon atoms, are conveniently prepared by heating to a temperature ranging from about 450 DEG C. to about 550 DEG C. a formamide or formanilide having the formula: Ar-A-NHCHO (II) or an amide having the formula: Ar-A-CONH2 (III) in the presence of a fluorinated siliceous catalyst, said catalyst having been prepared by (i) impregnating a particulate silica prepared by the precipitation of sodium silicate with sulfuric acid, with a dilute aqueous solution of hydrofluoric acid, said hydrofluoric acid solution having a concentration in HF of less than about 5% by weight, and the ratio by weight of the hydrofluoric acid contained in said aqueous solution thereof to the silica being less than about 5%, followed by (ii) drying the catalyst thus impregnated. |
