A novel technique for the preparation of secondary fatty amides. II. The preparation of ricinoleamide from castor oil

The butyl amide of ricinoleic acid (N-n-butyl-12-hydroxy-(9Z)-octadecenamide) was prepared from a neat mixture of castor oil and n-butylamine (fatty ester/amine molar ratio, 1:1.3). No catalyst was required. The identity and purity of the amide was assessed by thin-layer chromatography and confirmed by elemental analysis and by infrared and C13 nuclear magnetic resonance spectroscopy. High product yields were achieved at 45 and 65 degrees C in 48 and 20 h, respectively. The reaction was inhibited by the addition of trimethylpentane and dioxane, but not by water. An attempt was made to prepare the amide from methyl ricinoleate, rather than castor oil; even after 10 d only partial conversion was achieved. Attempts to prepare the amide from methyl-n-butylamine, rather than n-butylamine, were also unsuccessful. The ease with which secondary fatty amides can be produced from an oil that consists primarily of the glycerol esters of hydroxylated fatty acids indicates that the described procedure has industrial utility