Method for the synthesis of omega-amino-alkanoic acids
View Patent ↗The invention relates to a method for the synthesis of amino acids/esters of general formula NH 2 —(CH 2 ) n —COOR in which n is an integer between 5 and 14, and R is either H or an alkyl radical including from 1 to 4 carbon atoms, from natural long-chain mono-unsaturated fatty acids or esters including at least 10 adjacent carbon atoms per molecule, said method comprising: first converting, if necessary, said natural long-chain fatty acid or ester into a monounsaturated fatty acid/ester of general formula R 1 —(CH 2 ) m —CH═CH—(CH 2 ) p —COOR in which R 1 is H, CH 3 or a COOR radical, m is an integer between 0 and 14 and p is an integer between 2 and 11, then submitting the latter to a crossed catalytic metathesis reaction with a compound of formula R 2 —CH═CH—R 3 in which R 2 is either H or CN and R 3 is CN or CH 2 NH 2 , provided that if R 2 is CN, R 3 can be only CN, and finally converting the resulting product of the general formula R 3 —CH═CH—(CH 2 ) p —COOR into an amino-acid, either by hydrogenation, or by hydrogenation of the triple terminal bond, or by amination of the double terminal bond.
1. A process for synthesizing amino acids or amino esters of general formula NH 2 —(CH 2 ) n —COOR in which n represents an integer between 5 and 14, R is either H or an alkyl radical containing from 1 to 4 carbon atoms, and containing at least 0.2×10 −10 % by mass of 14 C, from monounsaturated long-chain natural fatty acids or esters containing at least 10 adjacent carbon atoms per molecule, which consists first in converting, in an optional first step, said long-chain natural fatty acid or ester, via a physical treatment, via homometathesis or via a microbiological fermentation process, into a monounsaturated fatty acid or ester of general formula R 1 —(CH 2 ) m —CH═CH—(CH 2 ) p —COOR in which R 1 represents H, CH 3 or a radical COOR, m is an integer between 0 and 14 and p is an integer between 2 and 11, and then subjecting said monounsaturated fatty acid or ester of general formula R 1 —(CH 2 ) m —CH═CH—(CH 2 ) p —COOR to a catalytic cross-metathesis reaction with a compound of formula R 2 —CH═CH—R 3 in which R 2 is either H or CN and R3 is H, CN or CH 2 NH 2 , with the proviso that if R 2 is CN, R 3 can be only CN, and finally converting the resulting product corresponding to the general formula R3-CH═CH—(CH 2 ) p —COOR, into an ω-amino acid by hydrogenation or by amination.
2. The process as claimed in claim 1 , wherein the synthesized monounsaturated fatty acid or ester of general formula R 1 —(CH 2 ) m —CH═CH—(CH 2 ) p —COOR is subjected to a metathesis reaction with acrylonitrile, and is then subjected to a hydrogenation.
3. The process as claimed in claim 2 , wherein an amino acid of formula NH 2 —(CH 2 ) 10 —COOH is synthesized by reacting acrylonitrile with oleic acid, followed by a hydrogenation of an intermediate compound of formula CN—CH═CH—(CH 2 ) 7 —COOH.
4. The process as claimed in claim 3 , wherein the amino acid of formula NH 2 —(CH 2 ) 10 —COOH is synthesized by reacting an excess of acrylonitrile with an oleic diacid of formula HOOC—(CH 2 ) 7 —CH═CH—(CH 2 ) 7 —COOH, followed by a hydrogenation of an intermediate compound of formula CN—CH═CH—(CH 2 ) 7 —COOH.
5. The process as claimed in claim 1 , wherein an amino acid of formula NH 2 —(CH 2 )10-COON is synthesized by reacting a 2-butenedinitrile of formula CN—CH═CH—CN with an oleic diacid of formula HOOC—(CH 2 ) 7 —CH═CH—(CH 2 ) 7 —COOH, followed by a hydrogenation of an intermediate compound of formula CN—CH═CH—(CH 2 ) 7 —COOH.
6. The process as claimed in claim 2 , wherein an amino acid of formula NH 2 —(CH 2 ) 7 —COOH is prepared from petroselinic acid, which is subjected to metathesis with acrylonitrile, the intermediate acid of formula CN—CH═CH—(CH 2 ) 4 —COOH then being hydrogenated.
7. The process as claimed in claim 2 , wherein an amino acid of formula NH 2 —(CH 2 ) 11 —COOH is prepared from an acid of formula CH 2 ═CH—(CH 2 ) 8 COOH obtained from pyrolysis of ricinoleic acid, via metathesis with acrylonitrile, and is then subjected to a hydrogenation.
8. The process as claimed in claim 2 , wherein an amino acid of formula NH 2 —(CH 2 ) 13 —COOH is prepared from the acid of formula CH 2 ═CH—(CH 2 ) 10 COOH, obtained, from pyrolysis of lesquerolic acid, via metathesis with acrylonitrile, and is then subjected to a hydrogenation.
9. The process as claimed in claim 2 , wherein an amino acid of formula NH 2 —(CH 2 ) 6 —COOH is prepared from cis-5-eicosenoic acid via metathesis with acrylonitrile, followed by hydrogenation.
10. The process as claimed in claim 2 , wherein an amino acid of formula NH 2 —(CH 2 ) 14 —COOH is prepared from erucic acid via metathesis with acrylonitrile, followed by hydrogenation.
11. The process as claimed in claim 1 , wherein an amino acid of formula NH 2 —(CH 2 ) 11 —COOH is prepared from an acid of formula CH 2 ═CH—(CH 2 ) 8 COOH obtained, from pyrolysis of ricinoleic acid, via metathesis with allylamine, and is then subjected to a hydrogenation.
12. An amino acid or amino ester of general formula NH 2 —(CH 2 ) n —COOR in which n represents an integer between 5 and 14, and R is either H or an alkyl radical containing from 1 to 4 carbon atoms made by the process of claim 1 , wherein the amino acid or amino ester contains at least 0.2×10 −10 % by mass of 14 C.