Patent GB-780575-A (GB)
Title: Improvements in or relating to the production of omega-amino acids and esters thereof
Filed: 1953-11-20
Abstract: Polyamides are prepared by heating o -amino acids containing at least 9 carbon atoms in the molecule or the methyl or ethyl esters thereof. Thus, spinnable resins are obtained on heating 9-amino nonylic acid, its ethyl ester (at above 200 DEG  C. with evolution of ethanol), 10-amino capric acid or 13-amino tridecanoic acid.  The preparation of the acids and esters is described (see Group IV (b)).ALSO:An o -amino acid having at least 9 carbon atoms in the molecule or the methyl or ethyl ester thereof is prepared by treating an unsaturated fatty acid having at least 8 carbon atoms in the molecule between the carbon atom of the carboxyl group and an unsaturated bond, or a methyl or ethyl ester or alkali metal salt thereof, with ozone to form the corresponding ozonide, converting the ozonide into an acid-aldehyde containing nine or more carbon atoms in the molecule or a methyl or ethyl ester or alkali metal salt thereof by heating in the presence or absence of sodium sulphite or bisulphite, and converting the acid-aldehyde or ester or salt thereof into an o -amino acid or a methyl or ethyl ester thereof by hydrogenation in the presence of ammonia and a hydrogenation catalyst or by reduction of an aldoxime formed by treatment of the aldehydic compound with hydroxylamine.  The esters may also be prepared indirectly by esterifying the intermediate acid-aldehyde salt with dimethyl or diethyl sulphate and then converting the resulting ester-aldehyde into the amino ester as above described.  The unsaturated acid starting material may be used in admixture with one or more saturated or other unsaturated fatty acids obtained from oils and fats.  The ozonized acid or ester may be decomposed by heating under reduced pressure or with steam distillation but preferably by heating in the presence of the above-specified sulphites.  Ozonization of the fatty acid salts in aqueous solution results in simultaneous decomposition of the resulting ozonides.  Ozonide decomposition of the acids yields aldehydes, lower fatty acids and dibasic acids in addition to the aldehyde-acid.  The amino acids and their esters yield polyamide resins on heating.  In examples: (1) ozone is passed into an aqueous solution of sodium oleate at 30-40 DEG  C. and an oil layer, obtained on cooling, comprising nonyl aldehyde and nonylic acid, is removed from an aqueous layer; the latter is reacted with aqueous hydroxylamine hydrochloride and acidified; azelaic acid and azelaic acid-aldoxime are separately recovered and the oxime is converted into 9-amino nonylic acid by reduction with aluminium amalgam and water; (2) oleic acid is reacted with ozone and the resulting ozonide is decomposed either by distillation, or heating at about 100 DEG  C. under 10 mm. pressure, nonyl aldehyde distilling off; azelaic acid and azelaic acid aldehyde are separated from the residue containing also nonylic acid by means of aqueous sodium carbonate and the alkaline extract is treated as in (1); (3) the ozonide of (2) is decomposed by dropping it into sodium sulphite while passing steam therein; the residue is washed with water and then hydrogenated in the presence of ammonia at elevated temperature and pressure whereupon the product is stripped, extracted with aqueous HCl and the resulting 9-amino-nonylic acid hydrochloride is converted into the free acid; (4) oleic acid is ozonized in turpentine and the ozonide decomposed by aqueous sodium bisulphite at about 50 DEG  C.; azelaic acid aldehyde is recovered from the turpentine and converted to the amino acid as in (3); (5) ethyl oleate is reacted as in (3) to give amino-nonylic acid ethyl ester; (6) oleic acid is reacted as in (4) to give the acid aldehyde, and an aqueous solution of the sodium salt of the acid-aldehyde is esterified with diethyl sulphate and the resulting ester-aldehyde is aminated as in (3); (7) following the above procedures, 9-undecylenic acid yields 10-amino capric acid or its ethyl ester, erucic acid yields 13-amino-tridecanoic acid or its ethyl ester, saponified whale oil yields 9-aminononylic acid and saponified beef tallow yields 9-aminononylic acid and by-products comprising capraldehyde and malonic di-aldehyde.