Ethanol → N-(2,4-Dimethylphenyl)-3-oxobutanamide

関与物質

反応条件

反応手順

2.48 kg/h (20.5 mol/h) of 2,4-dimethylaniline, 1.83 kg/h (21.3 mol/h) of diketene (purity 98%) and 8 kg/h of a mixture of 2.4 kg/h of ethanol and 5.6 kg/h of water are metered separately but simultaneously into a reactor which has been preheated to about 80° C. The reactor consists of a double-shell glass vessel of about 0.6 l capacity and is equipped with a stirrer, thermometer, reflux condenser and, at the bottom, with a run-off. Immediately the metering has started, the heat evolved by the reaction causes the reactor contents to reflux at about 85° C. The heating of the reactor is discontinued and the reaction is continued by limiting the reactor contents to about 0.3 1 by continuous pumping out. The reactor discharge is cooled to about 15° C. with stirring, and the light-colored crystals which are formed are separated from about 7 kg/h of the pale yellow mother liquor by filtration. The moist product, which is obtained at about 5 kg/h, is washed with about 4 kg/h of cold aqueous 30% strength ethanol and dried, leaving 4 kg/h (19.5 mol/h) of 2',4'-dimethylacetoacetanilide (melting point about 89° C.) corresponding to a yield of 95% based on amine.

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