Title of Invention

MANGANESE DIOXIDE-CATALYST FOR HYDROLYSING CARBOXYLIC ACID NITRILES

Abstract Manganese dioxide catalyst which contains at least 52% by weight of manganese and additionally at least one lanthanide compound , and also lithium, sodium, potassium, rubidium or caesium, and has a BET specific surface area of 50 to 550 m2/g of the general formula: MnMexMyOz, where x is between 0.05 and 0.002, y is between 0.06 and 0.02 and z is between 1.7 and 2.0, Me is at least one element of lanthanides, in is an alkali metal selected from the group of lithium, sodium, potassium, rubidium, caesium, and additional water of hydration may be present.
Full Text

Manganese dioxide-catalyst for hydrolysing carboxylic
acid nitriles
The invention relates to a novel manganese dioxide
catalyst which can be used for the hydrolysis of
organic nitriles to the corresponding carboxamides, and
to a process for preparing the catalyst. The invention
also relates to a catalytic process for hydrolysing
organic nitriles to the corresponding carboxamides with
the aid of the catalyst.
The invention relates in particular to a catalytic
process for hydrolysing 2-hydroxy-4-methylthio-
butyronitrile to 2-hydroxy-4-methylthiobutyramide, a
valuable intermediate in the preparation of 2-hydroxy-
4-methylthiobutyric acid, the hydroxyl analogue of
methionine (MHA), and salts thereof. These substances
find use as an animal feed additive, in particular in
poultry breeding. These methionine-like compounds can
replace methionine and significantly improve the
utilization of proteins in the feed.

The hydrolysis of 2-hydroxycarbonitriles (cyanohydrins)
is a special case of nitrile hydrolysis. It is not
possible to use any -of the known processes for
hydrolysing nitriles, in which strong bases may be
used, because a back reaction of the cyanohydrin to
aldehyde and hydrogen cyanide proceeds under these

reaction conditions.

The 2-hydroxy-4-methylthiobutyronitrile can also be
hydrolysed with highly concentrated mineral acids,
preferably with sulphuric acid, in a virtually
equimolar amount. In the first reaction step, the amide
of the substituted butyric acid forms. An industrially
readily realizable separation of 2-hydroxy-4-

methylthiobutyramide and sulphuric acid with the aim
of being able to reuse the sulphuric acid, is, however,
not known. Only after the hydrolysis of the amide to

the hydroxycarboxylic acid is the mineral acid removed
as ammonium hydrogensulphate, arid worked up back to
sulphuric acid in an additional, expensive process
step.

It is also known that manganese dioxide catalyses the
hydrolysis reaction of carbonitriles to amides, as
described, for example, in DE 1593320.
As a result of the incorporation of manganese of other
valence states into the crystal lattice, the
stoichiometric composition of natural and synthetic
manganese dioxide is in the range between MnO1.7 to
MnO2.0. Extraneous ions such as sodium, potassium may be
present in the crystals. Manganese dioxide exists in
several allotropic modifications. They differ greatly
in their behaviour as a catalyst. The crystallinity is

at its most marked in pyrolysite (beta-manganese
dioxide), the most stable modification. This form is
catalytically inactive. The crystalliciity is less
marked in the further modifications and] extends up to
an amorphous product, ramsdellite. It is possible to

assign the modifications by x-ray diffraction. Some of
the chemically and catalytically active forms of
manganese dioxide are hydrated and additionally contain
hydroxyl groups.
Numerous patents describe catalytic processes for
hydrolysing carbonitriles, especially 2-hydroxynitriles
(cyanohydrins), with manganese dioxide. These processes
are highly suitable, for example, for hydrolysing
acetone cyanohydrin, as shown in US-4018829, with which
yields of over 90% are achieved in the hydrolysis of
acetone cyanohydrin to 2-hydroxybutyramiide with the aid
of manganese dioxide.
The catalytically active modifications of manganese
dioxide are, however, also active as oxidizing agents,
which significantly restricts their use in the

hydrolysis of thioether- or thiol-substitsuted nitriles,
caused by their easy oxidizability. This reduces
tetravalent manganese partly to trivalent manganese,
and correspondingly oxidizes the sulphur.
DE 1593320 describes a process for hydrolysing nitriles

to amides with the aid of manganese dioxide, in which
yields up to over 90% were achieved with aliphatic
nitriles. Only 8% yield of amide was achieved with
thiodipropionitrile, which makes it clear that
conventional manganese dioxide is hardly suitable as a
catalyst in the presence of easily oxidizable thioether
groups.EP 0 597 298 describes a partial reduction of manganese
dioxide by a pretreatment with reducing agents such as
alcohol in order to improve the catalyst properties, in
particular to suppress oxamide formation there. With

increasing proportion of trivalent manganese oxide,
however, the activity of the catalyst declines.
The oxidizing action of manganese dioxide is generally

undesired in the hydrolysis of nitriles which bear

easily oxidizable groups such as thiol or thioether
groups. In particular, the S-oxidization is undesired
in the hydrolysis of 2-hydroxy-4-methylthio~
butyronitrile to 2-hydroxy-4-methylthiobutyramide, an

important intermediate in the preparation of the animal
feed additive 2-hydroxy-4-methylthiobutyric acid.
Oxidation of the sulphur forms the sulptioxide and this

ultimately reduces the yield of 2-hydroxy-4-methyl-

thiobutyramide. This by-product formed by oxidation
cannot be removed without a considerable level of cost
and inconvenience and then leads to a contaminated end
product which can no longer be used directly as an
animal feed additive.
The reduction of the catalyst which is associated with
the oxidization of the sulphur also shortens its



lifetime, which, in an industrial process, leads to
economic disadvantages, such as iricreased catalyst
consumption and regeneration complexity with
corresponding costs.
The patent JP 09104665 describes the preparation of

active δ-manganese dioxide and defines its activity via
the parameter of surface area. The hydrolysis of
2~hydroxy-4-methylthiobutyronitrile with full
conversion is also described with this catalyst. There
is no discussion whatsoever of the formation of
sulphoxide in this publication on the part of the
applicant. By virtue of adjustment of the conditions
specified there, it was, however, found that, during
the reaction, the sulphoxide of 2-hydroxy-4-methyl-
thiobutyronitrile is formed up to more than 4% in a
selectivity of at least 1.6% (comparative example,
Example 11), which is highly disadvantageous. Moreover,
the nitrile conversion was only 96.1%, the amide yield
7 9.8% in continuous mode.
The same applicant describes, in the patent
EP 0 731 079, a process for preparing carboxylic acids
by hydrolysing cyanohydrin with the aid of manganese
dioxide and subsequent hydrolysis of the amide formed
with alkali to give the salt of the carboxylic acid.

The electrodialysis then separates the carboxylic acid
and sodium hydroxide solution from one another. In
Example 3, in a column reactor with δ-manganese dioxide
(amorphous) not described in more detail the formation
of MHA amide at 50°C by hydrolysis of 2-hydroxy-
4-methylthiobutyronitrile with a nitrile conversion of
100% is reported at an MHA amide yield of even 100%. It
was likewise impossible to confirm this result.
Instead,. it was. found that, especially in a column
reactor with high catalyst concentration, the oxidizing
action of active manganese dioxide comes to bear. With
simultaneous reduction of manganese4+, this leads to
catalytically inactive Mn3+ and to increased formation

of the sulphoxide. The reworking of this example which
is quite similar to JP 09104665 also shows that the

sulphoxide of 2-hydroxy-4-methylthiobutyramide is
formed with a selectivity of approx. 2% to more than
4%.


The patent FR 2 750 9 87 solves the problem of the

oxidation of sulphur by coating silicon dioxide with
manganese dioxide. However, the catalyse contains only
5 to 10% of active catalyst constituents This must be

balanced out by the use of a large amount of catalyst
or by reaction times of 17 to 45 hours. For an
industrial process, this procedure is disadvantageous.



Against the background of the disadvantages of the
prior art, the inventors were faced with the object of
providing a catalyst based on manganese dioxide which
catalyzes the hydrolysis of carbonitriles which bear
easily oxidizable groups such as thiol| or thioether
groups, especially corresponding hydroxyhitriles to the
corresponding amides. The oxidizing action of this

catalyst should be sufficiently low that cyanohydrins
which bear oxidizable functional groups such as thiol
or thioether groups, i.e., for example, 2-hydroxy-4-
methylthiobutyronitrile, should also be hydrolysable
with it without significant S-oxidation. It was a

further object to provide a suitable preparation
process for the catalyst. It was a third object to
provide a hydrolysis process which is readily

performable industrially for carbonitriiles, which is
applicable to carbonitriles which bear easily
oxidizable groups such as thiol or thioether groups,
especially corresponding hydroxynitriples, with the
proviso that the disadvantages of the known processes,
especially the easy oxidation of sulphur, take place
only to a reduced degree, if at all.
These objects, and also further objects which are not
specified explicitly but which can immediately be

derived or discerned from the connections discussed
herein are achieved by a manganese dioxide catalyst
according to Claim 1, by a process for its preparation
according to Claim 6 and by a process for hydrolysing
nitriles with the aid of an inventive catalyst
according to Claim 16. Appropriate embodiments and
modifications of the invention catalyst, and of the
process for its preparation and for its use, are

protected in the subclaims referring back to Claim 1, 6
or 16.
The object was achieved in accordance with the
invention by providing a manganese dioxide catalyst
which contains at least 52% by weight of manganese,
preferably at least 53% by weight of manganese, more
preferably at least 55% by weight of manganese, and
additionally at least one lanthanide compound.

Surprisingly, it was found that the incorporation of
small amounts of lanthanides into the manganese dioxide
greatly reduced its undesired oxidizing action toward
thioether or thiol groups without adversely affecting
the catalytic action in the hydrolysis of
carbonitriles.
In particular, the object is achieved by providing a
catalyst of the type mentioned with the general
formula:
MnMexMyOz,
where x is between 0.05 and 0.002, y is between 0.06
and 0.02 and z is between 1.7 and 2.0, Me is at least
one element of lanthanides, M is an alkali metal
(lithium, sodium, potassium, rubidium, caesium), and
additional water of hydration may be present.
Elements particularly suitable in accordance with the
invention from the group of the lanthanides are cerium
and lanthanum. Particular preference is therefore given
to catalysts in which Me is cerium and/or lanthanum.


The manganese dioxides modified in accordance with the

invention contain, in addition to lanthanide, as
extraneous ions, preferably lithium) sodium or
potassium, most preferably potassium, which is
important in an advantageous manner for,the action in
the catalysis of nitrile hydrolysis. Particular

preference is thus also given to catalysts in which M
is potassium.
The manganese dioxides modified in accordance with the
invention have a specific surface area (BET) of 50 to
550 m2/g, preferably of 150 to 400 m2/g, most preferably
of 200 to 300 m /g, which is determined according to the
test method DIN66131.
The preparation of the catalyst is simple and can be

effected, for example, by a treatment of commercially

available active manganese dioxide with an aqueous
solution of a salt of the lanthanides. The inventive
process for preparing the catalyst is characterized in
that alkali metal-containing manganese dioxide is
reacted with at least one lanthanide salt in aqueous

solution or suspension, and the solid obtained is
removed, optionally washed and dried.
■ ;
The process for preparing the catalyst is preferably

performed in such a way that alkali metal-containing
manganese dioxide is reacted with at least one
lanthanide salt in aqueous solution or suspension in
the suitable molar ratios, so as to obtain the

resulting solid with the desired composition MnMexMyOz,
and this is removed, optionally washed and then dried.
Active manganese dioxide is typically prepared by the
reaction of potassium permanganate with sulphuric acid
solution of manganese(II) sulphate, as reported, for
example, in EP412310 in Example 1. THE salt of the
lanthanides can also be added to the reaction solution


A preferred process for preparing the inventive
catalyst consequently features, before and/or during
the reaction of manganese dioxide with lanthanide salt,
the direct preparation of the alkali metal-containing
manganese dioxide from alkali metal Permanganate,
preferably potassium permanganate, and manganese(II)
sulphate in sulphuric acid solution. This is

particularly inexpensive and affords particularly
active catalysts.
Alkali metal-containing manganese dioxide is preferably

prepared from approx. 2 molar equivalents of alkali

metal permanganate and approx. 3 molar equivalents of
manganese(II) sulphate.

To prepare the catalyst, it is possible to use either
inorganic or organic lanthanide salts,which further
simplifies the catalyst preparation.



In the case of the inorganic lanthanide salts,
preference is given to using the halides, nitrates,
sulphates or phosphates, the phosphates being the most
suitable.
In the case of the organic lanthanide salts, preference
is given to using the carboxylic salts, especially the
formates or acetates.

Since the inventive catalysts preferably contain cerium
and/or lanthanum, they are prepared preferably by using

the corresponding cerium and/or lanthanum salts.
The oxidizing action was the most reduced with
trivalent salts of cerium; these are therefore used
preferentially. It is also possible to use tetravalent
salts of cerium for catalyst preparation.

Preference is therefore given to employing a process in
which trivalent and/or tetravalent salts, of cerium are
used for catalyst preparation.
It has also been found that the most active catalysts
are obtained when the manganese dioxide used is present
in the crystal modification of α-manganese dioxide,
especially in the case of use of commercia1 material.
A further significant aspect of the invention is the
use of the inventive catalysts for the hydrolysis of
nitriles.
The inventive catalysts also feature, in addition to
the reduced sulphoxide formation in the hydrolysis of
thioether-containing nitriles, simultaneously the
achievement of further activation of the manganese
dioxide catalyst used compared to the manganese dioxide
catalysts prepared without lanthanide salt.
This is made clear especially by the comparison of the
hydrolysis results of Example 5 (manganese dioxide

catalyst without lanthanides), Example 6 (cerium-
containing manganese dioxide catalyst) and Example 9
(lanthanum-containing manganese dioxide catalyst).
While the conversion of 95.3% (Example 5) rises to
99.2% (Example 6) or 99.5% (Example 9) with
approximately equal residence time, the selectivity
with regard to undesired sulphoxide falls in the same
series from 5.2% to 1.1% or 1.9%.
The best activation of the catalyst and reduction of
sulphoxide formation in the hydrolysis reaction is
achieved by preparing the catalyst by the process
according to the invention described above in aqueous

solution or suspension. Mixing and trituration of the
manqanese dioxide with the lanthanide salts in a more

or less dry state leads only to limited success, as
made clear by the comparison of Examples 5, 6 and 7.

By performing a process for catalytically hydrolysing
thioether (S-R)-.or thiol (S-H)-substituted, preferably
S-R-substituted, carbonitriles of the general formula
R1-CR2R3-CN to the corresponding carboxamides with the
aid of the above-described inventive catalyst, where R1,
R and R may be the same or different and are each
hydrogen, at least one S-R- or S-H-substituted
hydrocarbon radical and R is optionally a hydroxyl
radical, where the particular hydrocarbon radical R1,
R2, R3 is a linear or optionally branched C1- to Cio-
alkyl radical, a C6- to C10-aryl radical, an O-, N-
and/or S-containing C4- to Cs-heteroaryl radical or a
C7- to C12-aralkyl radical, and the R radical is a
linear or optionally branched C1- to C4-alkyl C6- to
C10-aryl radical, an O-, N- and/or S-containing C4- to
Cs-heteroaryl radical or a C7- to C12-aralkyl radical,
the objects specified at the outset are achieved.

Preference is given to using S-R- or S-H-substituted,

especially S-R-substituted, carbonitriles in which R1 ,

R2, R3, R are each C1- to C4-alkyl, phenyl, naphthyl,
furyl, thienyl, imidazolyl, pyridyl, pyrimidyl or
indolyl, benzyl or naphthylmethyl, in the case that R3
is not a hydroxyl radical.

For example, in the case of 2-hydroxy-4-methylthio-
butyronitrile, the process is notable for conversion
rates of at least 96% up to 100%, depending on the
precise selection of the conditions, Especially by
virtue of sufficiently long reaction time, it is
possible to achieve nitrile conversions of at least
99%, preferably > 99.5% and up to 100%. At the same
time, the selectivities for the undesired S-oxidation
products of the hydrolysis of carbonitriles containing thioether
groups, selectivities of the undesired formation of

sulphoxide products of significantly below 2% of
theory, especially of preferably
preferably up to very particularly advantageous with regard to the end
product purity and with regard to the significantly
reduced purification complexity.
When used once, the catalyst does not lose its
activity. It is therefore possible without any problem
to separate the catalyst, after the hydrolysis reaction
has ended, from the reaction solution, and to use it
again. The reaction can therefore be performed
continuously and batchwise.
It has been found that, surprisingly, the oxidizing
action of the catalyst on repeated use declines further

without any deterioration in the performance for the

hydrolysis reaction. Thus, the selectivity of undesired

S-oxidation can be lowered down to of catalyst used is not critical and has an influence
only on the reaction rate.
It is particularly advantageous to use the catalyst in
a continuous process. In this case, the nitrile can be
hydrolysed by using catalyst-filled column reactors or

else suspension reactors. It is also possible to select

continuous stirred tank batteries or other embodiments

known to those skilled in the art.

In this hydrolysis reaction, water is simultaneously
solvent and reactant. The reaction is preferably
performed in such a way that from 10 to 200 mol of
water per mole of nitrile are used in the hydrolysis,

more preferably from 2 0 to 100 mol of water. Especially
in the case of hydrolysis of 2-hydroxy-4-methylthio-
butyronitrile, the range between 20 and 100 mol of
water per mole of nitrile is preferred. A larger amount
of water is not harmful for the conversion and
selectivity, but reduces the space-time yield.
Wherever it is more favourable for the solubility or

miscibility of the reactants used and hence of the
nitrile used, but especially in the case of a small
amount of water, an inert organic solvent such as C1- to
C4 alcohols, C3- to C6-ketones, preferably acetone, may
be added as a solubilizer.
The temperatures at which the process according to the
invention is performed can be varied within a wide
range. Advantageously, the hydrolysis of the nitrile
is, however, performed at temperatures of 10 to 90°C;
particular preference is given to a range from 2 0 to
50°C.
When cyanohydrins are used and higher temperatures of
over 90°C are employed, the reformation of aldehyde and
hydrogen cyanide from the cyanohydrin is promoted and

undesired by-products are formed. Therefore, a
temperature range of from 20°C to 50°C is very
particularly preferred here.

The process is preferably used to hydrolyse thioether
(S-R) - or thiol (S-H)-substituted carbonitriles of the
general formula R1-CR2-CN defined above, in which R3 is
hydroxy1.
Among the corresponding cyanohydrin compounds
R1 -CR2OH-CN, very particular preference is given to
those in which R1, R2 and R are represented by the Ci-

to C4-alkyl radicals as the alkyl radical, by phenyl or
naphthyl as the aryl radical, by furyl, thienyl,
imidazolyl, pyridyl, pyrimidyl or indolyl as the
heteroaryl radical, and by benzyl or naphthylmethyl as
the aralkyl radical.

In a quite outstanding manner, the process is suitable
for hydrolysing 2-hydroxy-4-methylthiobutyronitrile to
the corresponding 2-hydroxy-4-methylthiobutyramide.


The process can additionally also be used for the

hydrolysis of non-sulphur-containing cyanohydrins.
Excellent yield and selectivities are Jachieved when
acetone cyanohydrin is reacted under the above-
specified conditions with an inventive manganese

dioxide catalyst to give the isobutyramide, an
important precursor for methacrylic acid compounds. The
advantage here is in particular that it is possible
with the same catalyst to hydrolyse S-R- and S-H-
substituted nitriles and also unsubstituted nitriles.
The process can thus be performed successively for
sulphur-containing and for non-sulphur-containing
nitriles in the same plant without a catalyst change,
which advantageously increases the flexible usability
of such plants.
The examples which follow are intended to illustrate
the process without being restrictive.

Preparation of the catalyst:
.
Example 1:

30 g of commercially available α-manganese dioxide of
the HSA type from Erachem with a content of 1.6%

potassium, a manganese content of 55%, a particle size

range of 3.0 to 5.5 microns and a surface area of
230 m2/g together with 811 mg of cerium (III) phosphate
in 300 ml of demineralized water were stirred at 60°C
for 24 hours. Thereafter, the solid was filtered off by
means of a suction filter and washed with 11 of
demineralized water in 3 portions. The catalyst thus
prepared was dried at 110°C and 50 mbar for 20 hours.
The specific surface area of the catalyst after drying

was 239 in m2/g, the cerium content 0.97%.
Example 2:


Example 1 was repeated, except that 1.15 g of
cerium(IV) sulphate were used instead of cerium(III)
phosphate. The specific surface area of the catalyst
thus prepared after drying was 266 m2/g.

Example 3:

Example 1 was repeated, except that 1.4 g of
lanthanum(III) nitrate hexahydrate were used instead of

cerium(III) phosphate. The specific surface area of the

catalyst thus prepared after drying was 283 in m2/g.
; i

Example 4:
A round-bottomed flask with stirrer and dropping funnel
was initially charged with 14.2 g of potassium

permanganate and 1.76 g of cerium(III) phosphate
together with 550 ml of demineralized water and heated
to 85°C. Within 2 minutes, a solution, of 10.14 g of
manganese(II) sulphate in 250 ml of demineralized water


together with 4.1 g of concentrated sulphuric acid was
added dropwise with vigorous stirring. The resulting
black suspension was stirred at 85°C for a further

6 hours. After cooling to 25°C, the solid was removed

by suction filtering and washed with 21 of water in
5 portions. The catalyst was dried at 110°C and 50 mbar

over 14 hours.

.
Catalytic hydrolysis reaction:

Example 5: Comparative example (manganese dioxide
catalyst without lanthanides)

In a round-bottomed flask with mechanical stirring,
2 .0 g of unchanged α-manganese dioxide (HSA type from

Erachem) and 12 0 g of demineralized water were heated
to 40°C in a waterbath, and 13.1 g of 2-hydroxy-4-
methylthiobutyronitrile were added. After 2 hours, the
conversion of the cyanohydrin was 95.13%. The HPLC

analysis of the reaction solution showed a selectivity

of 5.2% for the sulphoxide of 2-hydroxy-4-methyl-
thiobutyramide.
Example 6:
The experiment of Example 5 was repeated, except that
the catalyst used was 2.0 g of the catalyst modified

with cerium(III) phosphate from Example 1. After a
reaction time of 2 hours at 40°C, 99.2% of the
cyanohydrin had been converted. The selectivity for the
sulphoxide was 1.1%.
Example 7:
30 g of commercially available α-manganese dioxide (HSA
type from Erachem) having a content of l.6% potassium
and a surface area of 230 m2/g were mixed with 811 mg of
cerium(III) phosphate and triturated finely in a
mortar. 2.0 g of this mixture were used as the catalyst


in the hydrolysis of 13.1 g of 2-hydroxy-4-methy1-
thiobutyronitrile with 12 0 g of water at a temperature
of 40°C. After 2 hours, 96.8% of the cyanohydrin had
been converted. The selectivity for the undesired
sulphoxide was 4.2%.
Example 8:
The experiment from Example 5 was repeated, except that
the catalyst used was 2.0 g of the catalyst modified
with cerium(IV) sulphate from Example 2. After a
reaction time of 2 hours at 45°C, 99.6 % of the
cyanohydrin had been converted. The selectivity for the
sulphoxide was 1.9%.
Example 9:
The experiment from Example 5 was repeated, except that
the catalyst used was 2.3 g of the catalyst modified
with lanthanum nitrate from Example 3 . After a reaction
time of 2.5 hours at 35°C, 99.5 % of the cyanohydrin
had been converted. The selectivity for the sulphoxide
was 1.9%.
Example 10:

In an experimental series, the catalyst was recycled.
To this end, in a round-bottomed flask with mechanical
stirring, 2.0 g of the modified manganese dioxide

according to Example 1 were heated with 12 0 g of
demineralized water to 40°C in a water bath, and 13.1 g

of 2-hydroxy-4-methylthiobutyronitrile were added.
After 2.5 hours, the conversion of the cyanohydrin was

99.8%. The selectivity for the sulphoxide was 1.1%.
Thereafter, the catalyst was filtered off and used
again in the hydrolysis reaction under the same
conditions. This operation was performed a further 5
times. Thereafter, the cyanohydrin conversion was still
99.8%; the selectivity for the sulphoxide declined to


0.2%.

Example 11: Comparative example (according to
JP 09104665, Example 2)

A glass column (diameter 1 cm, length 10 cm) was
charged with 10 g of manganese dioxide catalyst
(prepared according to JP 09104665, Example 1). A 10%
by weight aqueous 2-hydroxy-4-methy[lbutyronitrile
solution was pumped through the column in
countercurrent at 10 g/h at 40°C. The effluent solution
was analysed by means of HPLC. The run time was
100 hours from the start of the reaction. This gave a
nitrile conversion of 96.1% of theory, an amide yield
of 79.8% of theory ( = 83.0% selectivity) and a yield of
1.5% of theory of MHA amide sulphpxide (= 1.6%
selectivity) . The amide yield reported in JP09104665
Example 2 of at least 99.1% with 100% nitrile
conversion could not be confirmed in any way. The
yields decline even further when precisely 15% aqueous
2-hydroxy-4-methylbutyronitrile is used, since an oily
second phase comprising predominantly nitrile separates
out, which covers the catalyst and prevents uniform
conversion.
In an analogously performed batch experiment, 2 g of
manganese dioxide catalyst (prepared according to JP
09104665, Example 1) were reacted with 0.1 mol of 2-
hydroxy-4-methylbutyronitrile as a 10% by weight
aqueous solution at 40°C within 3.5 hours. The amide
yield was 81.6% of theory (= 84.1% selectivity), the

nitrile conversion 97.0% of theory. The yield of MHA
amide sulphoxide 4.0% of theory (= 4.1% selectivity)
based on nitrile used.

WE CLAIM :
1. Process for catalytic hydrolysis of S-R or S-H-substituted carbonitriles of the
general formula R1 -CR2 -R3 -CN to the corresponding carboxamides, where R1 ,

R2 and R3 may be the same or different and are each hydrogen, at least one S-
R- or S-H-substituted hydrocarbon radical selected from the group consisting
of a linear or optionally branched C1 to C10-alkyl radical, a C6- to C10-aryl
radical, an O-, N- and/or S-containing C4- to C8-heteroaryl radical or a C7- to


C12-aralkyl radical and R3 is optionally a hydroxyl radical and the R radical is
a linear or optionally branched C1 to C4-alkyl, C6- to C10-aryl radical, an O-,
N- and/or S-containing C4- to C8-heteroaryl radical pr a C7- to C12-aralkyl
radical, and wherein the hydrolysis is performed with the aid of a manganese
' dioxide catalyst which contains at least 52% by weight of manganese and
additionally at least one lanthanide compound, and also lithium, sodium,
potassium, rubidium or caesium, and has a specific BET surface area of 50 to
550m /g, of the general formula :
MnMexMyOz,

where x is between 0.05 and 0.002, y is between 0.06 and 0.02 and z is between
1.7 and 2.0, Me is at least one element of lanthanides, in is an alkali metal from
the group comprising lithium, sodium, potassium, rubidium, caesium, and
additional water of hydration may be present.

2. Process as claimed in claim 1, wherein S-R- or S-H-substituted carbonitriles
are used in which R1, R2, R3, R are each C1 to C4-alkyl, phenyl, naphthyl,
furyl, thienyl, imidazolyl, pyridyl, pyrimidyl or indolyl, benzyl or
naphthylmethyl, with the prerequisite that R is not a hydroxyl radical.
3. Process as claimed in claim 1, wherein S-R- or S-H- substituted carbonitriles
are used in which R is hydroxyl.
4. Process as claimed in claim 3, wherein S-R or S-H-substituted carbonitriles
are used in which R1 , R2 , R are each C1 to C4-alkyl, phenyl, naphthyl, furyl,
thienyl, imidazolyl, pyridyl, pyrimidyl or indolyl, benzyl or naphthylmethyl.

5. Process as claimed in claim 4,wherein 2-hydroxy-4-methylthiobutyronitrile
is used for the hydrolysis.
6. Process as claimed in at least one of claims 1 to 5, wherein the catalyst, when
the reaction has ended, is separated from the reaction solution and used again.

7. Process as claimed in at least one of claims 1 to 6, wherein the catalyst is
used in a continuous process.

8. Process as claimed in claim 7, wherein the nitrile is hydrolysed by using
column reactors or suspension reactors.

9. Process as claimed in at least one of claims 1 to 8, wherein 10 to 20 mol of
water are used per mole of nitrile in the hydrolysis.


10. Process as claimed in one of claims 1 to 9, wherein the hydrolysis of the
nitrile is performed in the presence of an inert organic solvent.
11. Process as claimed in at least one of claims 1 to 10, wherein the hydrolysis
of the nitrile is performed at temperatures of 10 to 90°C.
12. Process as claimed in any one of claims 1-10, wherein Me is cerium and/or

lanthanum in the manganese dioxide catalyst.
13. Process as claimed in one of claims 1-10, wherein the specific surface area

(BET) of the manganese dioxide catalyst is 150 to 400 m2/g.



ABSTRACT


Title: Manganese dioxide-catalyst for hydrolysing
carboxylic acid nitriles
Manganese dioxide catalyst which contains at least 52%
by weight of manganese and additionally at least one
lanthanide compound , and also lithium, sodium,
potassium, rubidium or caesium, and has a BET specific
surface area of 50 to 550 m2/g of the general formula:
MnMexMyOz,
where x is between 0.05 and 0.002, y is between 0.06
and 0.02 and z is between 1.7 and 2.0, Me is at least
one element of lanthanides, in is an alkali metal
selected from the group of lithium, sodium, potassium,
rubidium, caesium, and additional water of hydration
may be present.

Documents:

01347-kolnp-2008-abstract.pdf

01347-kolnp-2008-claims.pdf

01347-kolnp-2008-correspondence others.pdf

01347-kolnp-2008-description complete.pdf

01347-kolnp-2008-form 1.pdf

01347-kolnp-2008-form 2.pdf

01347-kolnp-2008-form 3.pdf

01347-kolnp-2008-form 5.pdf

01347-kolnp-2008-gpa.pdf

01347-kolnp-2008-international search report.pdf

01347-kolnp-2008-pct priority document notification.pdf

01347-kolnp-2008-pct request form.pdf

01347-kolnp-2008-translated copy of priority document.pdf

1347-KOLNP-2008-(01-03-2012)-CORRESPONDENCE.pdf

1347-KOLNP-2008-(20-09-2011)-ABSTRACT.pdf

1347-KOLNP-2008-(20-09-2011)-AMANDED CLAIMS.pdf

1347-KOLNP-2008-(20-09-2011)-DESCRIPTION (COMPLETE).pdf

1347-KOLNP-2008-(20-09-2011)-EXAMINATION REPORT REPLY RECIEVED.pdf

1347-KOLNP-2008-(20-09-2011)-FORM 1.pdf

1347-KOLNP-2008-(20-09-2011)-FORM 2.pdf

1347-KOLNP-2008-(20-09-2011)-FORM 3.pdf

1347-KOLNP-2008-(20-09-2011)-OTHERS.pdf

1347-KOLNP-2008-CANCELLED PAGES.pdf

1347-KOLNP-2008-CORRESPONDENCE OTHERS 1.1.pdf

1347-KOLNP-2008-CORRESPONDENCE.pdf

1347-KOLNP-2008-EXAMINATION REPORT.pdf

1347-kolnp-2008-form 18.pdf

1347-KOLNP-2008-GPA.pdf

1347-KOLNP-2008-GRANTED-ABSTRACT.pdf

1347-KOLNP-2008-GRANTED-CLAIMS.pdf

1347-KOLNP-2008-GRANTED-DESCRIPTION (COMPLETE).pdf

1347-KOLNP-2008-GRANTED-FORM 1.pdf

1347-KOLNP-2008-GRANTED-FORM 2.pdf

1347-KOLNP-2008-GRANTED-FORM 3.pdf

1347-KOLNP-2008-GRANTED-FORM 5.pdf

1347-KOLNP-2008-GRANTED-SPECIFICATION-COMPLETE.pdf

1347-KOLNP-2008-INTERNATIONAL EXM REPORT.pdf

1347-KOLNP-2008-INTERNATIONAL PUBLICATION.pdf

1347-KOLNP-2008-INTERNATIONAL SEARCH REPORT & OTHERS.pdf

1347-KOLNP-2008-OTHERS.pdf

1347-KOLNP-2008-PCT REQUEST FORM 1.1.pdf

1347-KOLNP-2008-PETITION UNDER RULE 134.pdf

1347-KOLNP-2008-REPLY TO EXAMINATION REPORT 1.1.pdf

1347-KOLNP-2008-REPLY TO EXAMINATION REPORT.pdf

1347-KOLNP-2008-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf


Patent Number 256077
Indian Patent Application Number 1347/KOLNP/2008
PG Journal Number 18/2013
Publication Date 03-May-2013
Grant Date 30-Apr-2013
Date of Filing 03-Apr-2008
Name of Patentee EVONIK DEGUSSA GMBH
Applicant Address RELLINGHAUSER STRASSE 1-11, 45128 ESSEN
Inventors:
# Inventor's Name Inventor's Address
1 HORST WEIGEL AHORNWEG 11, 63517 RODENBACH
2 DR. CRISTOPH WECKBECKER AUGUST-IMHOF-STR. 25, 63584 GRUNDAU-LIEBLOS
3 AXEL RONNEBURG ROMERSTRASSE 39, 63526 ERLENSEE
PCT International Classification Number B01J 23/34
PCT International Application Number PCT/EP2006/066820
PCT International Filing date 2006-09-28
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10 2005 047 597.3 2005-10-05 Germany