Method for synthesizing an omega-amino acid or ester from a monounsaturated fatty acid or ester

摘要

A method for synthesizing ω-amino-alkanoic acids or the esters thereof from natural unsaturated fatty acids passing through an intermediate ω-unsaturated nitrile compound. The method is simple to implement and, relative to known methods, avoids the environmental constraints and economic disadvantages resulting from the reaction by-products. The method includes synthesizing an ω-amino acid (ester) of formula R3OOC—(CH2)q-CH2NH2, in which R3 is H or an n-butyl radical and q is an integral index of between 2 and 13, from a monounsaturated fatty acid (ester) of formula (R1-CH═CH—(CH2)p-COO)xR2, in which x represents 1, 2 or 3, R1 is H or a hydrocarbon radical comprising from 4 to 11 carbon atoms and, where appropriate, a hydroxyl function, R2 is H or an alkyl radical comprising from 2 to 4 carbon atoms, and may contain one or more heteroatoms, and p is an integral index of between 2 and 11, including a reaction step of ammoniation.

主权项

1. A process for synthesizing an ω-amino acid (ester) of formula R3OOC—(CH2)q—CH2NH2, in which R3 is H or an n-butyl radical and q is an integral index of between 2 and 13, from a monounsaturated fatty acid (ester) of formula (R1—CH═CH—(CH2)p—COO)xR2, in which x represents 1, 2 or 3, R1 is H or a hydrocarbon radical comprising from 4 to 11 carbon atoms and, where appropriate, a hydroxyl function, R2 is H or an alkyl radical comprising from 2 to 4 carbon atoms, and may contain one or more heteroatoms, and p is an integral index of between 2 and 11, comprising a reaction step of ammoniation, leading to the conversion of the carbonyl function to a nitrile function, wherein:
in a first stage, the unsaturated fatty acid/ester is converted into an ω-unsaturated nitrile of formula CH2═CH—(CH2)p—CN in two successive steps, in any order, ethenolysis and ammoniation, and then in a second stage, this ω-unsaturated nitrile is converted into an ester nitrile of formula R3OOC—CH═CH—(CH2)p—CN, in which R3 is n-butyl, by a cross metathesis reaction of the ω-unsaturated nitrile with an acrylate of formula CH2═CH—COOR3, with a catalyst of formula (I),and then
in a third stage, the ester nitrile is hydrogenated to ω-amino acid (ester) of formula ROOC—(CH2)q—CH2NH2.