Process for preparing saturated amino acids or
saturated amino asters comprising a metathesis step
5 The invention is targeted at a process for the
synthesis of long-chain a,co-aminoalkanoic acids or
esters from a monounsaturated fatty acid or ester
comprising at least one metathesis stage.
10 The polyamides industry, whether to manufacture
synthetic fibers or thermosetting resins, uses a whole
range of monomers consisting of diamines, diacid , and
in particular long-chain an-amino acids. The latter are
normally referred to as Nylon, defined by the length of
15 the methylene chain (-CH2-)n separating two amide
-CO-NH- functional groups. Thus it is that Nylon 6,
Nylon 6-6, Nylon 6-10, Nylon 7, Nylon 8, Nylon 9, Nylon
11, Nylon 13, and the like, are known.
20 These monomers are generally manufactured by the
chemical synthesis route using in particular, as
starting materials, C2 to C4 olefins, cycloalkanes or
benzene, hydrocarbons resulting from fossil sources,
but also, in some specific cases, starting from castor
25 oil (Nylon 11) or erucic oil (Nylon 13/13) or
lesquerolic oil (Nylon 13).
Current developments in environmental matters are
leading, in the fields of energy and chemistry, to the
30 exploitation of natural starting materials originating
from a renewable source being favored. This is the
reason why some studies have been undertaken to
develop, on the industrial scale, processes using fatty
acids/esters as starting material for the manufacture
35 of these monomers,
This type of approach has only a few industrial
CONFIRMATION COPY
WO 2011 / 138051 PCT/EP2011 / 002295
2 --
examples. One of the rare examples of an industrial
process using a natural fatty acid as starting material
is that of the manufacture, from ricinoleic acid
extracted from castor oil, of 11-aminoundecanoic acid,
5 which is the base for the synthesis of Rilsan 110". This
process is described in the work "Les Procedes de
Petrochimie" [Petrochemical Processes] by A. Chauvel et
al. which appeared in Editions Technip (1986).
11-Aminoundecanoic acid is obtained in several stages.
10 The first consists of a methanolysis of castor oil in a
basic medium, producing methyl ricinoleate, which is
subsequently subjected to a pyrolysis in order to
obtain, on the one hand, heptanaldehyde and, on the
other hand, methyl undecylenate. The latter is
15 converted to the acid form by hydrolysis. Subsequently,
the acid formed is subjected to a hydrobromination to
give the a)-brominated acid, which is converted by
ammoniation to 11-aminoundecanoic acid.
20 In this "bio" route, the main studies related to the
synthesis of 9-aminononanoic acid, which is the
precursor of Nylon 9, from oleic acid of natural
origin.
25 As regards this specific monomer, mention may be made
of the work "n-Nylons, Their Synthesis, Structure and
Properties", 1997, published by J. Wiley and Sons,
chapter 2.9 (pages 381 to 389) of which is devoted to
Nylon 9. This article summarizes the achievements with
30 regard to and. the studies carried out on the subject.
Mention is made therein, on page 381, of the process
developed by the former Soviet Union which resulted in
the commercialization of Pelargon«. Mention is also
made therein, on page 384, of a process developed in
35 Japan which uses oleic acid from soybean oil as
starting material. The corresponding description refers
to the work by A. Ravve, "Organic Chemistry of
Macromolecules" (1967), Marcel Dekker, Inc., part 15 of
WO 20 1 1/138051 PCT/E'P201 1 /002295
3 -
which is devoted to polyamides and which mentions, on
page 279, the existence of such a process.
For its part, the applicant company has carried out
studies in this field. It has described, in the French
patent application published under number FR 2912741, a
process for the synthesis of a whole range of amino
acids/esters of this type from
fatty acid/ester by subjecting
a natural long-chain
10 catalytic cross metathesis reaction
compound comprising a nitrile
followed by
application
unsaturated long-chain fatty
process for the
15 synthesis of w-ami.noalkanoic acids or their esters from
natural
through
nitrile
employs,
20
FR 0857780, it also described a
an
type,
a hydrogenation. In
the latter to a
with an unsaturated
functional group,
the French patent
filed on November 17, 2008 under number
acids passing
intermediate compound of o)--unsaturated
one of the alternative forms of which
in the final phase, a cross metathesis of the
w-unsaturated nitrile with a compound of acrylate type,
Finally, in
February 5,
the French patent application filed on
2009 under number FR 0950704, it described
an alternative form of the above process in which the
intermediate compound is of the unsaturated dinitrile
25 type. All these processes result in a final stage of
hydrogenation of the nitrile functional group and of
the double bond.
The object of the process of the invention is to
30 improve the performance of processes employing, in the
final phase, successively a cross metathesis and a,
hydrogenation. This is because it is important to be
able to have available an efficient catalysis of these
two successive reactions while minimizing the number of
35 operations, which naturally has an effect on the final
cost.
The hydrogenation of the nitrile functional group
WO 2011/138051 PCT/` P201°1,/0•02295
give a primary amine is generally carried out on the
industrial scale using highly reducing heterogeneous
catalysts, such as Raney cobalt or nickel. The use of
other metals known for their catalytic activity in
5 hydrogenation has also been envisaged under
heterogeneous conditions. Mention may be made, for
example, of platinum, palladium, ruthenium or iridium,
alone or in combination. Mention may be made, by way of
illustration, of patent UK 1 177 154, which describes
10 the use of various catalysts, Raney nickel, palladium
or platinum, for the hydrogenation of the nitrile
functional group of 11-cyanoundecanoic acid, and patent
UK 1 273 874, which describes the use of a ruthenium
catalyst deposited on silica for the same reaction,
15 resulting in 12-aminododecanoic acid. However, nickel
deposited on a support, such as silica, is the catalyst
most generally adopted.
The homogeneous catalysis of this hydrogenation
20 reaction of nitriles to give amines has also been the
subject of studies and is described in the literature.
Mention may be made, for example, of the hydrogenation
of benzonitrile to give benzylamine with homogeneous
ruthenium catalysts described by M. Hidai et al. in
25 Organometallics, 2002, 21, 3897, and in the paper by
R.H. Morris et al. in Organometallics, 2007, 26, 5940-
5949, and in the paper by M. Beller et al, in
ChemSusChem, 2008, 1, 1006; Chem. Eur. J., 2008, 14,
9491; Tetrahedron Lett., 2009, 50, 3654. The addition
30 of a base in order to carry out this type of reaction
is described,in these papers.
The sequence of reactions, metathesis and then
hydrogenation of the metathesis products, is described
35 in patent application US 2009/048459 of Cargill, which
describes a method for producing hydrogenated
metathesis products with successive stages of
metathesis and hydrogenation in which the hydrogenation
W'9 2011/138051 PCT/EP2011/002295
- 5 -
stage is carried out by treating the metathesis
reaction medium, containing the metathesis catalyst,
using a heterogeneous hydrogenation catalyst
consisting, according to all the examples, of supported
5 nickel. It may also be specified that the reaction
carried out in the examples is a homometathesis of
soybean oil which results, due to the composition of
this oil and the absence of any separation of the
metathesis reaction products, in a complex mixture of
10 esters and not in a monomer capable of being
polymerized.
In point of fact, the applicant company has discovered
that it is possible, in the process, to carry out the
15 metathesis and hydrogenation stages using just one
initial catalytic compound thus comprising the same
active metal as catalyst. The metathesis catalyst,
degraded at the end of the metathesis reaction,
fulfils, during the second stage, the role of
20 hydrogenation catalyst.
A subject matter of the invention is a process for the
synthesis of a saturated long-chain u,w-amino ester
(acid) comprising from 6 to 17 carbon atoms,
25 characterized in that it is obtained, in a first stage,
by a cross metathesis reaction between a first acrylic
compound, chosen from acrylonitrile, acrylic acid or an
acrylic ester, and a second monounsaturated compound
comprising at least one nitrile, acid or ester
30 trivalent functional group, one of these compounds
comprising a nitrile functional group and the other an
acid or ester functional group, in the presence of a
metathesis catalyst of ruthenium carbenes type, and, in
a second stage, by the hydrogenation of the
35 monounsaturated nitrile-ester (acid) obtained in the
presence of the metathesis catalyst from the preceding
stage acting as hydrogenation catalyst. The metathesis
reaction under consideration is a cross metathesis
WO 2011/138051 PCT/EP2011/002295
6
reaction between a monounsaturated acid or ester
compound, generally resulting from oleochemistry, with
acrylonitrile, or a cross metathesis reaction between
an unsaturated nitrile compound, generally resulting
from oleochemistry, with an acrylic compound, an acid
or acrylate, and, in this case, preferably methyl
acrylate.
The process has been developed for the purpose of the
10 exploitation of starting materials resulting from
renewable natural sources. However, it can also clearly
be applied to the analogous monounsaturated compounds
obtained by chemical synthesis.
15 The metathesis stage is carried out according to the
following reaction scheme:
+° RICH=CH3
20 with R1 = H or (CH2),, Rg,
R2 = COOR5 or CN,
R3 = COOR5 or CN,
Rn = H or R2,
R5 = alkyl radical of 1 to 4 carbon atoms,
25 n = 2 to 13,
m = 4 to 11, and
R2 is different from R3.
The formula of the final a, e)-amino ester (acid)
30 synthesized essentially depends on that of the compound
which reacts with the acrylic compound.
In this compound resulting from oleochemistry, i.e.
obtained from renewable natural fatty esters or acids,
35 R1 is either H or an alkyl radical or a functional
alkyl radical comprising a trivalent functional group
(CN, COOH or COOR).
WO 201 1 /138051 PCT/EP2011 / 002295
- 7 -
R1 will be H when the natural fatty ester will, for
example, be subjected to an ethenolysis or, in some
cases, to a pyrolysis. The formula of the a,w-amino
5 ester/acid obtained is then directly related to the
-(CH2)1.- radical of the fatty ester. Thus it is that n
will be equal to 7 with oleic acid, to 4 with
petroselenic acid, to 8 from ricinoleic acid subjected
to a pyrolysis, to 10 from lesquerolic acid subjected
10 to a pyrolysis and the like, as is described in the
French patent application published under number FR 2
912 741,
R will be an alkyl radical when, in (CH2)n,-R4, R4 is H.
15 This corresponds to the use in the process of a
monounsaturated natural fatty acid such as, for
example, oleic acid, palmitoleic acid, petroselenic
acid, lauroleic acid, and the like.
20 R1 will be a functional alkyl radical when, in
(CH2)m Ra, R4 is a radical representing a CN, 000H or
COOR trivalent functional group which will be identical
to R2. The compound will then be in the diacid, diester
or dinitrile form. It will then be particularly
25 advantageous for the formula of the compound to exhibit
a symmetry which makes it possible to optimize the
yields of final a,ca-amino ester/acid. The production of
compounds of this type, in particular by metathesis, is
described in the abovementioned applications FR
30 2912741, FR 0857780 and FR 0950704.
As regards the acrylic compound, the choice of the
trivalent functional group R3 is related to the nature
of the trivalent functional group of the other
35 compound, R3 having to be nitrite when R2 is ester/acid
and conversely ester/acid when R2 is nitrile.
This reaction results in unsaturated nitrile--acids or
WO 2011/138051 PCT/ P2011/002295
8
nitrile-esters.
Preferably, the cross metathesis reaction with
acrylonitrile is carried out with a compound chosen
5 from 9-decenoic acid or methyl 9-decenoate, resulting
from the ethenolysis of oleic acid or methyl oleate,
10-undecenoic acid or methyl 10-undecenoate, resulting
from the cracking of ricinoleic acid or methyl
ricinoleate, oleic acid or methyl oleate,
10 9-octadecenedioic acid or methyl 9-octadecenedioate,
resulting from the homometathesis or fermentation of
oleic acid, erucic acid and methyl erucaie, or
12-tridecenoic acid or methyl 12--tridecenoate,
resulting from lesquerolic acid.
15
The cross metathesis reaction of the acrylic ester
(acid) is carried out with a compound chosen from
9--decenenitrile, resulting from 9-decenoic acid,
10-undecenenitrile, resulting from 10-undecenoic acid,
20 9-octadecenenitrile or oleonitrile, resulting from
oleic acid, 9-octadecenedinitrile, resulting from
9-octadecenedioic acid, eruconitrile or 12-
tridecenonitrile, resulting from lesquerolic acid.
25 The cross metathesis reaction with a compound of
acrylic type is carried out under conditions which are
fully known. The metathesis reaction is preferably
carried out at a reaction temperature of between 20 and
120°C and under a pressure of between 1 and 30 bar, in
30 the presence of a ruthenium-based catalyst. It will
preferably be carried out at a low pressure of between
1 and 10 bar and more preferably at atmospheric
pressure when the cross metathesis results in the
formation of a light compound, for example ethylene, in
35 order to make possible easy release thereof. The
reaction can be carried out without solvent or in the
presence of a solvent, such as toluene, xylenes or
dichloromethane, benzene, chlorobenzene or dimethyl
WO 2011/138051 PC;T/EP2011/002295
9
carbonate,
The catalysis of the metathesis reaction has been the
subject of a great many studies and the development of
sophisticated catalytic systems. Mention may be made,
for example, of the tungsten complexes developed by
Schrock et al. (J. Am. Chem. Soc., 108 (1986), 2771) or
Basset et all, Angew. Chem., Ed. Engl., 31 (1992), 628.
10 "Grubbs'" catalysts have more recently appeared (Grubbs
et all, Angew. Chem., Ed. Engl., 34 (1995), 2039, and
Organic Letters 1 (1999), 953), which are rutheniumbenzylidene
complexes operating in homogeneous
catalysis.
15
Finally, studies have been carried out for the
preparation of immobilized catalysts, that is to say,
catalysts having an active principle which is that of
the homogeneous catalyst, in particular ruthenium-
20 carbene complexes, but which is immobilized on an
inactive support. The objective of these studies is to
increase the selectivity of the cross metathesis
reaction with regard to side reactions, such as
"homometatheses" between the reactants brought
25 together. They relate not only to the structure of the
catalysts but also to the effect of the reaction medium
and the additives which may be introduced.
The ruthenium catalysts are preferably chosen from
30 charged or uncharged catalysts of general formula:
(X1)a(X2)hRu(carbene C) (L1)c(L2)a(L3)e
in which:
e a, b, c, d and e are identical or different integers,
with a and b equal to 0, 1 or 2; c, d and e equal to 0,
35 1, 2, 3 or 4;
e X1 and X2, which are identical or different, each
represent a charged or uncharged and monochelating or
polychelating ligand; mention may be made, by way of
WO 2011 / 138051 PCT/EP2 0 11/002295
- 10 -
examples, of halides, sulfate, carbonate, carboxylates,
alkoxides, phenolates, amides, tosylate,
hexafluorophosphate, tetrafluoroborate,
bis(triflyl)amide, an alkyl, tetraphenylborate and
5 derivatives. X1 or X2 can be bonded to (L1 or L2) or to
the (carbene C) so as to form a bidentate or chelate
ligand on the ruthenium; and
Ll, L2 and L3, which are identical or different, are
electron-donating ligands, such as phosphine,
10 phosphite, phosphonite, phosphinite, arsine, stilbene,
an olefin or an aromatic compound, a carbonyl compound,
an ether, an alcohol, an amine, a pyridine or
derivative, an imine, a thioether or a heterocyclic
carbene;
15 L1, L2 or L3 can be bonded to the (carbene C) so as to
form a bidentate or chelate ligand, or a tridentate
ligand;
the (carbene C) being represented by the general
formula: C (R1) (R2), for which R1 and R2 are identical
20 or different groups, such as hydrogen or any other
saturated or unsaturated and cyclic, branched or linear
hydrocarbon group or aromatic hydrocarbon group.
Mention may be made, by way of examples, of ruthenium
alkylidene, benzylidene or cumulene complexes, such as
25 vinylidenes Ru=C=CHR or allenylidenes Ru=C=C=CR1R2 or
indenylidenes.
A functional group which makes it possible to improve
the retention of the ruthenium complex in an ionic
30 liquid can be grafted to at least one of the ligands
X1, X2, Li or L2 or to the carbene C. This functional
group can be charged or uncharged, such as, preferably,
an ester, an ether, a thiol, an acid, an alcohol, an
amine, a nitrogenous heterocycle, a sulfonate, a
35 carboxylate, a quaternary ammonium, a guanidinium, a
quaternary phosphonium, a pyridinium, an imidazolium, a
morpholinium or a sulfonium.
WO 2011/138051 PCr,./EP2011 /002295
- 11 -
The metathesis catalyst can optionally be rendered
heterogeneous on a support in order to facilitate the
recovery/recycling thereof.
5 The cross metathesis catalysts of the process of the
invention are preferably ruthenium carbenes described,
for example, in Aldrichimica Acta, Vol. 40, No. 2,
2007, pp. 45-52. The preferred catalysts are the
catalyst Umicore M51 (sold by Umicore) of formula (A)
10 below, and the 2nd generation Hoveyda-Grubbs catalyst,
also known as Hoveyda II (sold by Sigma-Aldrich), of
formula (B) below.
{A)
15
The reaction time is chosen as a function of the
reactants and operating conditions employed and in
order to reach the end of the reaction.
20 As the metathesis is an equilibrium reaction, it is
advisable to shift this equilibrium in order to proceed
towards total conversion. In order to do this in the
case where the co-product of the reaction is a light
olefin, such as ethylene, it is easy to "degas" the
25 reactor from time to time in order to force the removal
of the light products and thus to proceed towards total
conversion. In the case where the co-product is a
heavier olefin, optionally a functional one, the
extraction operation is more problematic insofar as it
30 is necessary to keep the two reactants and the catalyst
110 2011/138051. PCT/EP2011/002295
- 12 -
in the reaction medium, Furthermore, if it is necessary
to separate, at least in part, the unsaturated nitrileester
(acid) by distillation and to remove the light
products before the hydrogenation, the operation has to
5 be carried out so that the metathesis catalyst remains
in the heavy fraction with the nitrile--ester (acid) in
order to use it in its role of hydrogenation catalyst.
In this operation, during the separation, the very
heavy compounds are not removed from the medium, which
10 compounds would thus be hydrogenated with the heavy
fraction, their separation occurring during a
subsequent purification of the final amino acid/enter.
The other way of shifting the equilibrium is to use an
15 excess of reactant, typically in this instance an
excess of acrylonitrile or alkyl acrylate (generally
methyl acrylate)e From a processing viewpoint, the
first stage would be carried out to completion with the
exhausting of the metathesis catalyst, the excess
20 acrylate or acrylonitrile would be distilled for
recycling, and then, in a second stage, the unsaturated
a,cu-nitrile-ester/acid compound present in the reaction
medium would be hydrogenated in the presence of the
metal of the catalyst of the let stage in its.
25 hydrogenation role.
The amount of ruthenium metathesis catalyst introduced
during the first stage is chosen so that it ensures all
the possible conversion of the nonacrylic reactant
30 present in the charge. It is observed that said
catalyst, under the operating conditions of the
metathesis stage, is converted after the reaction; it
is exhausted or deactivated and loses its catalytic
activity after metathesis -- it will be subsequently
35 denoted by the term "degraded" for said reactions In
the batch process, the amount of catalyst can easily be
adjusted in order to give the desired conversion at
complete degradation of the catalyst..
W07 2011/138051 PCT/E 2Q11/c02295
After the metathesis stage, the reaction medium
comprising the ruthenium is thus subjected to a
hydrogenation. The ruthenium metathesis catalyst is
degraded on completion of the metathesis stage but the
metal is still present in the reaction medium in a form
appropriate for the hydrogenation stage,.
The hydrogenation reaction is thus directly carried out
10 on the reaction mixture resulting from the metathesis
stage and in the presence of the residual metathesis
catalyst acting as hydrogenation catalyst, under a
hydrogen pressure and in the presence of a base. The
pressure is between 5 and 100 bar, preferably between
15 20 and 30 bar, The temperature is between 50 and 150°C,
preferably between 80 and 100°C. The base can be, for
example, sodium hydroxide, potassium hydroxide,
potassium tert butoxide or ammonia, The base is
generally used at a content of 10 to 80 mol% with
20 respect to the unsaturated nitrile-ester substrate.
The hydrogenation reaction can be carried out with or
without solvent. In the case of a reaction in a solvent
medium, the preferred solvents used for the metathesis
25 and hydrogenation stages are aromatic solvents, such as
toluene or xylenes, or a chlorinated solvent, such as
dichloromethane or chlorobenzene, or dimethyl
carbonate.
30 On conclusion of this hydrogenation stage carried out
without a specific hydrogenation catalyst, the degree
of conversion of the nitrile functional group to give a
primary amine is particularly high, even without
addition of NH3, and also, of course, the reduction of
35 the olefinic unsaturation, without the carboxyl
functional group having been affected.
It is thus shown, unexpectedly, that the degraded
WO 2011/138051 PCT/EP2011/002295
- 14 -
metathesis catalyst exhibited activity and selectivity
for the hydrogenation of the unsaturated nitrile-acids
or nitrite-esters to give saturated amino acids or
amino esters.
The degraded metathesis catalyst can optionally be
employed with, in addition, a conventional
hydrogenation catalyst for the hydrogenation stage.
Mention may be made, among the metals conventionally
10 used for the hydrogenation, of nickel, palladium,
platinum, rhodium or iridium. Preferably, the degraded
metathesis catalyst might be supplemented by Raney
nickel or palladium-on-charcoal,
15 Thus, in a specific embodiment, the hydrogenation
reaction is carried out in the presence of the degraded
metathesis catalyst resulting from the first stage
supplemented by a conventional hydrogenation catalyst,
20 It can also be employed in the presence of a solid
support (charcoal, SiC, and the like) in order to
simplify its recovery.
The amino acids or amino esters obtained according to
25 the process of the invention can be used as monomers in
the synthesis of polyamides,
A further subject matter of the invention is polymers
obtained by polymerization of the a,w-amino esters
30 (acids) synthesized according to the processes defined
above.
The process of the invention is illustrated by the
following examples.
35
Example 1
Cross metathesis of methyl undecenoate with,
WO 2011/138051
- 15 -
PCT/:E.f2011/ 002295
acrylonitrile, followed by hydrogenation, with the
Hoveyda-Grubbs II catalyst:
5
100 mg of methyl 10-undecenoate (0.5 mmol), 53 mg of
acrylonitrile (1 mmol) and 10 ml of toluene distilled
over sodium benzophenone are charged to a 50 ml Schlenk
tube purged with nitrogen. 9.5 mg of 2nd generation
10 Hoveyda-Grubbo catalyst (1.5 x 10-2 mmol, supplier
Sigma-Aldrich) are added and the mixture is heated at
100°C for 4 hours.
The gas chromatography analysis shows that the
15 conversion of the methyl 10-undecenoate is 100 mol%
(96 mol%) and that the yield of unsaturated nitrileester
is 95 mol°.
The reaction mixture is then transferred into a 50 ml
20 Parr bomb (22 ml) . 17 mg of potassium hydroxide
(0.3 mmol) are added and the bomb is pressurized under
20 bar of hydrogen. It is heated at 80°C for 48 h with
magnetic stirring.
25 The gas chromatography analysis shows that the
conversion of the unsaturated nitrile--ester is 100 mol%
and that the yield of methyl 12-aminododecanoate is
90 mol%.
30 Example 2
Cross metathesis of methyl undecenoate with
acrylonitrile, followed by hydrogenation, with Umicore
M51 catalyst:
35
The procedure is the same as in example 1, the HoveydaWO
2011/138051 PCT/EP2011/002295
- 16 -
10
15
Grubbs II catalyst being replaced with 10 mg of Umicore
M51 catalyst (1.5 x 10-2 mmol, supplier Umicore), and
the potassium hydroxide being replaced with 8.5 mg of
potassium tert-butoxide (0.075 mmol).
The gas chromatography analysis shows that the yield of
methyl 12-aminododecanoate is 88 mol%,
Example 3
Undecenenitri_le/methyl acrylate cross metathesis,
followed by hydrogenation, with the Hoveyda-Grubbs II
catalyst:
kS:n rnix 'dxi U
83 mg of 10-undecenenitrile (0.5 mmol), 86 mg of methyl
acrylate (1 mmol) and 10 ml of toluene distilled over
sodium benzophenone are charged to a 50 ml Schlenk tube
20 purged with nitrogen. 9.5 mg of 2nd generation Hoveyda-
Grubbs catalyst (1.5 x 7.0-2 mmol) are added and the
mixture is heated at 100°C for 1 hour.
The gas chromatography analysis shows that the
25 conversion of the 10-undecenenitrile is 100% and that
the yield of unsaturated nitrile-ester is 98%.
The reaction mixture is then transferred into a 50 ml
Parr bomb (22 ml). 17 mg of potassium tert-butoxide
30 (0.15 mmol) are added and the bomb is pressurized under
20 bar of hydrogen. The bomb is heated at 80°C for 40 h
with magnetic stirring.
The gas chromatography analysis shows that the
35 conversion of the unsaturated nitrile-ester is 100 mol%
and that the yield of methyl 12-aminododecanoate is
110 2011 / 138051 PCT"/EP2011 / 0•02295
- 17 -
90 mol%.
Example 4
Methyl undecenoate/acrylonitrile cross metathesis with
Hoveyda-Grubbs II catalyst, followed by hydrogenation,
with supplementary addition of Pd/C catalyst:
100 mg of methyl 10-undecenoate (0.5 mmol), 53 mg of
10 acrylonitrile (1 mmol) and 10 ml of toluene distilled
over sodium benzophenone are charged to a 50 ml Schlenk
tube purged with nitrogen. 3 mg of 2nd generation
Hoveyda-Grubbs catalyst (5 x 10-3 mmol) are added and
the mixture is heated at 100°C for 4 hours.
15
The gas chromatography analysis shows that the
conversion of the methyl 10-undecenoate is 98% and that
the yield of unsaturated nitrile-ester is 93%.
20 The reaction mixture is then transferred into a 50 ml
Parr bomb (22 ml). 10 mg of 1% Pd/C catalyst and 17 mg
of potassium tert-butoxide (0.15 mmol) are added and
the bomb is pressurized under 20 bar of hydrogen. The
bomb is heated at 80°C for 48 h with magnetic stirring.
25
The gas chromatography analysis shows that the
conversion of the unsaturated nitrile--ester is 90% and
that the yield of methyl 12-aminododecanoate is 64%.
30
WO 2011/138051 PCT'/EP2011/002295
- 18 -

Claims
le A process for the synthesis of a saturated long-
5 chain a,co-amino ester (acid) comprising from 6 to
17 carbon atoms, characterized in that it is
obtained, in a first stage, by a cross metathesis
reaction between a first acrylic compound, chosen
from acrylonitrile, acrylic acid or an acrylic
10 ester, and a second monounsaturated compound
comprising at least one nitrile, acid or ester
trivalent functional group, one of these compounds
comprising a nitrile functional group and the
other an acid or ester functional group, in the
15 presence of a metathesis catalyst of ruthenium
carbenes type, and,, in a second stage, by the
hydrogenation of the monounsaturated nitrile-ester
(acid) obtained in the presence of the metathesis
catalyst from the preceding stage acting as
20 hydrogenation catalyst.
2a The process as claimed in claim 1, characterized
in that the metathesis stage is carried out
according to the following reaction scheme:
25
RI (LH2),'R2 4
+R1CH=CHR3
with
R1 = H or (CH2)m-R4,
30 R2 = COOR5 or CN,
R3 = COOR5 or CN,
R4 = H or R2,
R5 = alkyl radical of 1 to 4 carbon atoms,
n = 2 to 13, in = 4 to 11, and
35 R2 is different from R3-
H f
3. The process as claimed in either of claims 1 and
WO 2011/138051 PCT/EP2011/002295
- 19 -
2, characterized in that the cross metathesis
reaction with acrylonitrile is carried out with a
compound chosen from 9-decenoic acid, methyl
9-decenoate, 10-undecenoic acid, methyl
10-undecenoate, oleic acid, methyl oleate,
9-octadecenedioic acid, methyl 9-octadecenedioate,
erucic acid, methyl erucate, 12-tridecenoic acid
and methyl 12-tridecenoate.
10 4. The process as claimed in either of claims 1 and
2, characterized in that the cross metathesis
reaction of the acrylic ester (acid) is carried
out with a compound chosen from 9-decenenitrile,
10-undecenenitrile, 9-octadecenenitrile or
15 oleonitrile, 9-octadecenedinitrile, eruconitrile
or 12-tridecenonitril_e.
5. The process as claimed in one of claims 1 to 4,
characterized in that the metathesis reaction is
20 carried out at a reaction temperature of between
20 and 120°C and under a pressure of between 1 and
30 bar and preferably of between 1 and 10 bar.
6. The process as claimed in one of claims 1 to 5,
25 characterized in that the metathesis reaction is
carried out in the presence of a ruthenium
catalyst chosen from charged or uncharged
catalysts of general formula:
30 (X1)a(X2)bRu(carbene C)(L1)c(L2)d(L3)e
in which:
e a, b, c, d and e are identical or different
integers, with a and b equal to 0, 1 or 2; c, d
and e equal to 0, 1, 2, 3 or 4;
35 o Xl and X2, which are identical or different,
each represent a charged or uncharged and
monochelating or polychelating ligand, preferably
chosen from halides, sulfate, carbonate,
110 2011/138051 PCT/EP2011/002295
- 20 -
carboxylates, alkoxides, phenolates, amides,
tosylate, hexafluorophosphate, tetrafluoroborate,
bis(triflyl)amide, tetraphenylborate and
derivatives. Xl or X2 can be bonded to Yl or Y2
5 (Ll or L2) or to the (carbene C) so as to form a
bidentate or chelate ligand on the ruthenium; and
e Ll, L2 and L3, which are identical or different,
are electron-donating ligands, such as phosphine,
phosphite, phosphonite, phosphinite, arsine,
10 stilbene, an olefin or an aromatic compound, a
carbonyl compound, an ether, an alcohol, an amine,
a pyridine or derivative, an imine, a thioether or
a heterocyclic carbene;
it being possible for Ll, L2 or L3 to be bonded to
15 the (carbene C) so as to form a bidentate or
chelate ligand, or a tridentate ligand, the
(carbene C) being represented by the general
formula: C (R1) (R2), for which R1 and R2 are
identical or different groups, preferably hydrogen
20 or any other saturated or unsaturated and cyclic,
branched or linear hydrocarbonyl group or aromatic
hydrocarbonyl group.
7. The process as claimed in claim 6, characterized
25 in that the metathesis catalyst corresponds to
either of the formulae (A) and (B) below:
WO 2011/1 3c8051
8. The process as claimed in one of claims 1 to 7,
characterized in that the hydrogenation reaction
is carried out on the reaction mixture resulting
from the metathesis stage and in the presence of
the residual metathesis catalyst acting as
hydrogenation catalyst, under a hydrogen pressure
and in the presence of a base.
9. The process as claimed in one of claims 1 to B,
10 characterized in that the hydrogenation reaction
is carried out at a pressure of 5 and 1.00 bar,
preferably between 20 and 30 bar, and at a
temperature of between 50 and 150°C, preferably
between 80 and 100°C.
15
10. The process as claimed in one of claims 1 to 9,
characterized in that the hydrogenation reaction
is carried out in the presence of a base chosen
from sodium hydroxide, potassium hydroxide,
20 potassium tert-butoxide or ammonia, at a content.
of 10 to 80 mol% with respect to the unsaturated
nitrile-ester substrate.
11. The process as claimed in one of claims 1 to 10,
25 characterized in that the hydrogenation reaction
is carried out in the presence of the degraded
metathesis catalyst resulting from the first stage
supplemented by a conventional hydrogenation
catalyst.
30
12. A polymer obtained by polymerization of the a,w--
amino esters (acids) synthesized according to the
processes of claims 1 to 11...