Amino acid preparation method comprising a step of hydroformylation of an unsaturated fatty nitrile
A process for synthesizing an ω-amino acid compound of formula HOOC—(CH 2 ) r+2 —CH 2 NH 2 , wherein 4≤r≤13 from a monounsaturated fatty nitrile compound of formula CH 2 ═CH—(CH 2 ) r —CN the process comprising: 1) a step of hydroformylation of the mono unsaturated fatty nitrile compound by reacting said nitrile with carbon monoxide and di hydrogen 5e-a5 to obtain a nitrile aldehyde compound of formula HOC—(CH2)r+2-CN, then 2) a step of oxidation, in the presence of dioxygen, of the nitrile aldehyde compound to obtain a corresponding nitrile acid compound of formula HOOC—(CH2)r+2-CN, and 3) a step of reduction of the nitrile acid compound to give an w-amino acid of formula HOOC—(CH 2 ) r+2 —CH 2 NH 2 .
1. A process for synthesizing an ω-amino acid compound of formula
HOOC—(CH 2 ) r+2 —CH 2 NH 2 ,
wherein r is an integer wherein 4≤r≤13
from a monounsaturated fatty nitrile compound of formula
CH 2 ═CH—(CH 2 ) r —CN
the process comprising:
1) a step of hydroformylation of the monounsaturated fatty nitrile compound by reacting said nitrile with carbon monoxide and dihydrogen to obtain a nitrile aldehyde compound of formula HOC—(CH 2 ) r+2 —CN, then
2) a step of oxidation, in the presence of dioxygen, of the nitrile aldehyde compound to obtain a corresponding nitrile acid compound of formula HOOC—(CH 2 ) r+2 —CN, and
3) a step of reduction of the nitrile acid compound to give an ω-amino acid of formula
HOOC—(CH 2 ) r+2 —CH 2 NH 2 .
2. The process as claimed in claim 1 , wherein the hydroformylation is catalyzed in the presence of a catalyst system comprising:
at least one metal of groups V to XI of the periodic table of elements, selected for its nitrile conversion activity; and
at least one bidentate or monodentate ligand selected for the selectivity of the hydroformylation reaction in favor of the linear aldehyde.
3. The process as claimed in claim 2 , wherein the catalyst system comprises at least one phosphine, one phosphite or one chelating diphosphine selected from the group consisting of PPh 3 , P(OPh) 3 , Dppm, Dppe, Dppb and Xantphos.
4. The process as claimed in claim 2 , wherein the metal of the catalyst system is provided in the form of a precursor comprising said metal and at least one compound selected from the group consisting of acetylacetonates, carbonyl compounds, and mixtures thereof.
5. The process as claimed in claim 2 , wherein the hydroformylation catalyst system comprises rhodium, and/or ruthenium.
6. The process as claimed in claim 2 , wherein the hydroformylation is catalyzed by a catalyst system selected from the group consisting of Rh—PPh 3 , Rh—P(OPh) 3 and Rh-Xantphos, and mixtures thereof.
7. The process as claimed in claim 2 , wherein the [ligand]/[metal] molar ratio is included in the range of from 60:1 to 1:1.
8. The process as claimed in claim 1 , wherein the hydroformylation is carried out in an organic medium.
9. The process as claimed in claim 1 , wherein the hydroformylation is carried out at a temperature included in the range of from 70 to 150° C.
10. The process as claimed in claim 1 , wherein the hydroformylation is carried out for a period of time ranging from 2 to 24 hours.
11. The process as claimed in claim 1 , wherein the hydroformylation is carried out at a partial CO/H 2 pressure included in the range of from 5 to 50 bar and according to a CO:H 2 ratio included in the range of from 1:3 to 3:1.
12. The process as claimed in claim 1 , wherein the [Substrate]/[Metal] ratio is included in the range of from 5000 to 500 000.
13. The process as claimed in claim 1 , wherein the oxidation step is carried out by sparging dioxygen or a dioxygen-containing gas mixture in the product resulting from the hydroformylation, optionally in the presence of the hydroformylation catalyst.
14. The process as claimed in claim 1 , wherein the oxidation step is carried out without the addition of solvent and/or without the addition of dioxygen activation catalyst.
15. The process as claimed in claim 1 , wherein the oxidation step is carried out at a partial dioxygen pressure ranging from 1 bar to 50 bar.
16. The process as claimed in claim 1 , wherein the dioxygen is continuously injected into the reaction medium by bubbling.
17. The process as claimed in claim 1 , wherein a molar ratio of the dioxygen relative to the product resulting from the hydroformylation step is included in the range of from 3:2 to 100:2.
18. The process as claimed in claim 1 , wherein the oxidation is carried out at a temperature included in the range of from 0° C. to 100° C., optionally in 2 consecutive increasing stationary temperature phases.
19. The process as claimed in claim 2 , wherein the hydroformylation step comprises the recycling of the hydroformylation catalyst system, optionally supplemented by a provision of new catalyst and/or ligand during a subsequent hydroformylation cycle.
20. The process as claimed in claim 19 , wherein the recycled catalyst system is obtained by at least partial evaporation of solvent and/or of nitrile-aldehyde and/or of unreacted reagent.
21. The process as claimed in claim 1 , wherein the hydroformylation step results in a selectivity of at least 95% of linear aldehydes.
22. The process as claimed in claim 1 , also comprising a step of catalytic cross metathesis with an alkene selected from the group consisting of ethylene, propylene, but-1-ene and but-2-ene, carried out on a unsaturated fatty nitrile before step 1) R2-CH to produce the monounsaturated fatty nitrile compound of formula CH 2 ═CH—(CH 2 ) r —CN.