GB781549A - Process for preparing fatty acid di-hydroxyalkyl amides, and products of such process - Google Patents

Abstract

N : N-Di-(hydroxyalkyl)-amides of fatty acids are prepared by adding to a preformed quantity of such amide in the liquid state a fatty acid ester, di(hydroxyalkyl) amine and an amidation catalyst, reacting the ester and amine to form the amide and recovering the latter. The reaction may be carried out in two stages by removing some of the liquid and completing the reaction separately, e.g. at a higher temperature. When this is done continuously sufficient amide must be left behind to maintain the reactants in a homogeneous liquid phase. The fatty acid ester used may be that of a mono-, dior polyhydric alcohol but it is preferred to use an ester of a monohydric alcohol of 1-5 carbon atoms such as methanol or ethanol, as these alcohols can easily be removed from the product by distillation. Glyceride esters may, however, be used. The fatty acids may be saturated or unsaturated acids of 10-22 carbon atoms whose esters are normally not miscible with di-(hydroxyalkyl) amines. The catalyst may be an alkali metal or amide or alkoxide thereof, particularly suitable being the alkoxide obtained by reacting the di-(hydroxyalkyl) amine reactant with concentrated aqueous alkali hydroxide and distilling off the water; such catalyst may be formed in situ. In the examples diethanolamine is reacted with methyl laurate, the methyl ester of coconut acids, and palm oil to give the corresponding amides. Other specified reactants are the esters of palmitic, stearic, myristic, oleic, ricinoleic, linoleic and linolenic acids, including lard, coconut oil, corn oil, cottonseed oil, soy bean oil and hydrogenated fish oil, also fatty acids of beeswax and carnauba wax. Besides glycerol and methanol the esterifying alcohol may be another alkanol, glycol, sorbitol, mannitol, inositol or pentaerythritol; the latter may be partly or wholly esterified. Other amines that may be used are dipropanolamine, dibutanolamine, dipentanolamine, dihexanolamine, dioctanolamine and di-glycerol-mono- and diamines.