11-aminoundecanoic acid

11-Aminoundecanoic acid is an organic compound with the formula H2N(CH2)10CO2H. This white solid is classified as an amine and a fatty acid. 11-Aminoundecanoic acid is a precursor to Nylon-11. 11-Aminoundecanoic acid is an organic compound with the formula H2N(CH2)10CO2H. This white solid is classified as an amine and a fatty acid. 11-Aminoundecanoic acid is a precursor to Nylon-11. As practiced by Arkema, 11-aminoundecanoic acid is prepared industrially from undecylenic acid, which is derived from castor oil. The synthesis proceeds in four separate reactions: 1. Transesterification of castor oil to methyl ricinoleat: Crude castor oil consists to about 90% of the triglyceride of ricinoleic acid. It is quantitatively transesterified with methanol to methyl ricinoleat (the methyl ester of ricinoleic acid) in the presence of the basic sodium methoxide at 80 °C within 1 h reaction time in a stirred reactor. At the end of the reaction, the resulting glycerol separates and the liquid methyl ester is washed with water to remove residual glycerol. 2. Pyrolysis of methylricinoleate to heptanal and methyl undecenoate: Methylricinoleat is evaporated at 250 °C, mixed with hot steam (600 °C) in a 1:1 ratio and decomposed in a cracking furnace at 400 - 575 ° C at a retention time of about 10 seconds into its cleavage products heptanal and methyl undecenoate. The cleavage of the aliphatic chain occurs in this variant of the steam cracking selectively between the hydroxymethylene and the allyl-methylene group. Besides heptanal and methyl undecenoate, a mixture of methyl esters of saturated and unsaturated C18-carboxylic acids is obtained. This mixture is known under the trade name Esterol® and is used as a lubricant additive. 3. Hydrolysis of methyl undecenoate to 10-undecenoic acid The hydrolyis of the methyl ester with sodium hydroxide proceeds at 25 °C within 30 min with quantitative yield. After acidification with hydrochloric acid, solid 10-undecenoic acid (undecylenic acid) is obtained.