GB641443A - Improvements in or relating to the stabilisation of unsaturated ketones - Google Patents

Abstract

Unsaturated ketones which are normally liquid are stabilized against colour change by incorporating therein a minor proportion of a secondary amine. Preferred amines are morpholine and aliphatic mono-amines in which the nitrogen atom is attached to a secondary carbon atom in each of the alkyl groups, e.g. di-sec-butylamine and di-isopropylamine, but many others are specified as suitable; the amount of amine used is normally about 0.01 to 3 per cent by weight. The stabilization is effective even in the presence of iron. The amine may be added to the ketone as such, or added to only a portion thereof and the resulting mixture added to the remaining ketone in an amount sufficient to attain the desired concentration. The pure ketone may be recovered from the stabilized mixture by suitable means, e.g. distillation, fractionation, adsorption and solvent extraction. The process is particularly adapted to ketones having an unsaturated group of at least 3 carbon atoms, such group including an unsaturated tertiary carbon atom, especially when the latter is in the beta position with respect to the carbonyl group. Suitable ketones are listed, both those belonging to these two types and others. Tables are given showing the colour developed in mesityl oxide both with and without a secondary amine as stabilizer.