U.S. patent application number 09/735900 was filed with the patent office on 2001-08-09 for method for producing a heterocyclic nitrile.
Invention is credited to Kimura, Manabu, Matsubara, Mitsuhide, Shiomi, Yasuhiro, Shoji, Takayuki.
Application Number | 20010012892 09/735900 |
Document ID | / |
Family ID | 18467350 |
Filed Date | 2001-08-09 |
United States Patent
Application |
20010012892 |
Kind Code |
A1 |
Shoji, Takayuki ; et
al. |
August 9, 2001 |
Method for producing a heterocyclic nitrile
Abstract
A method for producing a heterocyclic nitrile in high yield by a
gas-phase catalytic reaction of a heterocyclic carboxylic acid or
an ester thereof with ammonia in the presence of a catalyst
comprising an oxide of at least one element selected from copper
and zinc, and an effective method for producing a heterocyclic
aldehyde, using the heterocyclic nitrile thus obtained as a
starting material, are provided.
Inventors: |
Shoji, Takayuki; (Osaka,
JP) ; Matsubara, Mitsuhide; (Osaka, JP) ;
Kimura, Manabu; (Osaka, JP) ; Shiomi, Yasuhiro;
(Osaka, JP) |
Correspondence
Address: |
Thomas P. Pavelko, Esquire
STEVENS, DAVIS, MILLER & MOSHER, L.L.P.
1615 L Street, N. W., Suite 850
Washington
DC
20036
US
|
Family ID: |
18467350 |
Appl. No.: |
09/735900 |
Filed: |
December 14, 2000 |
Current U.S.
Class: |
540/610 ;
544/180; 544/242; 544/336; 544/98 |
Current CPC
Class: |
C07D 213/84
20130101 |
Class at
Publication: |
540/610 ; 544/98;
544/180; 544/242; 544/336 |
International
Class: |
C07D 223/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 17, 1999 |
JP |
11-359993 |
Claims
What is claimed is:
1. A method for producing a heterocyclic nitrile by a gas-phase
catalytic reaction of a heterocyclic carboxylic acid or an ester
thereof with ammonia in the presence of a catalyst comprising an
oxide of at least one element selected from copper and zinc.
2. The method according to claim 1 wherein the heterocyclic
carboxylic acid has a pyrrole ring, an imidazole ring, an
imidazoline ring, a pyrazole ring, a pyridine ring, a pyrimidine
ring, a quinoline ring, an oxazine ring, a pyrazine ring, a
triazine ring or an azepine ring, and contains only one carboxyl
group.
3. The method according to claim 1 wherein the heterocyclic
carboxylic acid is a nitrogen-containing heterocyclic carboxylic
acid in which the heterocycle has only one or two nitrogen atoms as
the hetero atom.
4. The method according to claim 1 wherein the catalyst comprises a
mixture of a copper oxide and a zinc oxide, a complex oxide of
copper and zinc, or a mixture thereof.
5. The method according to claim 4 wherein the weight ratio of
copper and zinc in the catalyst is 0.05-99.5:1 in term of the ratio
of copper oxide and zinc oxide.
6. A method for producing a heterocyclic aldehyde comprising a
gas-phase catalytic reaction of a heterocyclic carboxylic acid or
an ester thereof with ammonia in the presence of a catalyst
comprising an oxide of at least one element selected from copper
and zinc for producing a heterocyclic nitrile, and a catalytic
hydrogenation of the heterocyclic nitrile thus produced in the
presence of a hydrogenation catalyst and an acid in an aqueous
solvent.
7. The method according to claim 6 wherein the catalytic
hydrogenation is conducted in the presence of a copper salt.
8. The method according to claim 6 wherein the hydrogenation
catalyst is Raney nickel.
9. The method according to claim 8 wherein the Raney nickel is
treated with a copper salt.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method for producing a
heterocyclic nitrile by a reaction of a heterocyclic carboxylic
acid or an ester thereof with ammonia.
[0002] So far, as a method for producing a heterocyclic nitrile by
a reaction of a heterocyclic carboxylic acid or an ester thereof
with ammonia, a method is known in which 6-methylnicotinate and
ammonia are reacted to produce 2-methyl-5-cyanopyridine in the
presence of phosphorus oxychloride. [Izv Akad. Nauk kaz. SSR, Ser.
Khim. (1977), 27(5), 89-90]
[0003] Yield of 2-methyl-5-cyanopyridine in the known method is,
however, only 35%, and a method in which a heterocyclic nitrite can
be produced in a higher yield has been desired.
[0004] An object of the present invention is to provide a method in
which a heterocyclic nitrile can be produced in a higher yield and
a higher selectivity ratio by a reaction of a heterocyclic
carboxylic acid or an ester thereof with ammonia.
[0005] Inventors of the present invention have conducted extensive
studies to attain the above objects. As a result, they have found
that a conspicuously higher yield and selectivity ratio can be
attained when a gas-phase catalytic reaction of a heterocyclic
carboxylic acid or an ester thereof with ammonia is conducted in
the presence of a catalyst comprising an oxide of at least one
element selected from copper and zinc.
[0006] Inventors of the present invention have further found that,
using a heterocyclic nitrile thus produced as a starting material,
a heterocyclic aldehyde can be produced effectively.
SUMMARY OF THE INVENTION
[0007] The present invention provides a method for producing a
heterocyclic nitrite by a gas-phase catalytic reaction of a
heterocyclic carboxylic acid or an ester thereof with ammonia in
the presence of a catalyst comprising an oxide of at least one
element selected from copper and zinc.
[0008] The present invention also provides a method for producing a
heterocyclic aldehyde comprising a gas-phase catalytic reaction of
a heterocyclic carboxylic acid or an ester thereof with ammonia in
the presence of a catalyst comprising an oxide of at least one
element selected from copper and zinc for producing a heterocyclic
nitrile, and a catalytic hydrogenation of the heterocyclic nitrile
thus produced in the presence of a hydrogenation catalyst.
EMBODIMENTS OF THE INVENTION
[0009] In the present invention, a heterocyclic carboxylic acid or
an ester thereof is used as a starting material. The heterocyclic
carboxylic acid usable in the present invention is a compound
having a heterocycle containing at least one atom selected from a
nitrogen atom, a sulfur atom and an oxygen atom as a hetero atom,
and at least one carboxyl group bonded to a carbon atom in the
heterocycle. Preferably, the heterocyclic carboxylic acid Contains
a nitrogen atom as the hetero atom in the heterocycle. Examples of
the heterocycle include pyrrole ring, imidazole ring, imidazoline
ring, pyrazole ring, pyridine ring, pyrimidine ring, quinoline
ring, oxazine ring, pyrazine ring, triazine ring and azepine ring.
Particularly preferred is a nitrogen-containing heterocyclic
carboxylic acid in which the heterocycle contains only one carboxyl
group and only one or two nitrogen atoms as the hetero atom, such
as pyridine carboxylic acid, pyrazine carboxylic acid and
pyrimidine carboxylic acid. The heterocyclic carboxylic acid in the
present invention includes an acid anhydride thereof.
[0010] Examples of the ester of heterocyclic carboxylic acid usable
in the present invention include an alkyl ester of heterocyclic
carboxylic acid as described above. The alkyl in the alkyl ester is
not particularly limited. Examples thereof include a straight chain
or branched alkyl having one to four carbon atoms. Among them,
methyl and ethyl are preferred.
[0011] In the method of the present invention, a catalyst
comprising an oxide of at least one element selected from copper
and zinc is used. The oxide of at least one element selected from
copper and zinc include a copper oxide, a zinc oxide, a complex
oxide of copper and zinc, and a mixture thereof. Preferably, the
catalyst comprises an oxide of copper and an oxide of zinc, that
is, it comprises a mixture of a copper oxide and a zinc oxide, a
complex oxide of copper and zinc, or a mixture thereof. The weight
ratio of copper and zinc in the catalyst containing both copper and
zinc is preferably 0.05-99.5:1, more preferably 0.2-8.0:1 in terms
of the ratio of copper oxide and zinc oxide.
[0012] The catalyst used in the present invention may further
comprise an oxide of a metal other than copper and zinc as an
additional ingredient or a promoter as long as it does not inhibit
the gas-phase catalytic reaction of the present invention. Examples
of the metal other than copper and zinc include barium, chromium
and molybdenum, although the metal is not limited to them.
[0013] The catalyst used In the present invention can be produced
according to a conventional known method for producing metal oxide
catalysts. An oxide of at least one element selected from copper
and zinc which Is available on the market can also be used, as it
is, as the catalyst usable in the present invention. The catalyst
is molded into a desired shape, such as powder, column, cylinder,
sphere, tablet, to be used in the gas-phase catalytic reaction of
the present invention.
[0014] Copper compounds and zinc compounds usable as a starting
material for producing the catalyst in the present invention are
not particularly limited. Examples thereof include complexes,
acetates, carbonates, halides, hydroxides, nitrides, ammonium
salts, phosphates, sulfates, oxalate, lactates, formates and oxides
of copper and zinc.
[0015] An oxide of an element selected from copper and zinc can be
used as the catalyst as it is. The oxide may be supported on an
inert carrier commonly used as a carrier for a conventional
catalyst. Examples of the carrier include oxides of silicon,
titanium, zirconium or aluminum. Among them an oxide of silicon is
particularly preferred.
[0016] The gas-phase catalytic reaction of the present invention is
usually conducted by feeding a heterocyclic carboxylic acid or an
ester thereof and ammonia in a reactor where a catalyst described
above has already been charged. (Hereinafter, the term
"heterocyclic carboxylic acid" includes not only a heterocyclic
carboxylic acid but also an ester.) Amount of ammonia is usually
about 1-100 mol, preferably 2-20 mol, per 1 mol of the heterocyclic
carboxylic acid
[0017] When a heterocyclic carboxylic acid having a high melting
point, such as pyridine carboxylic acid, is used in the present
invention, it is preferred that the heterocyclic carboxylic acid is
dissolved in a suitable solvent, since it can be easily fed in a
reactor with a simple apparatus and a simple operation. The
solvents is stable during the gas-phase catalytic reaction of the
present invention and inert against the heterocyclic carboxylic
acid, ammonia and heterocyclic nitrile. For example, when the
heterocyclic carboxylic acid is a nitrogen-containing heterocyclic
carboxylic acid, such as pyridine carboxylic acid, or an ester
thereof, water, pyridine bases such as pyridine, 2-picoline,
3-picoline and 4-picoline, aromatic hydrocarbons such as toluene
and xylene, and the like can be used as the suitable solvent. The
solvent is used in an amount so that content of the heterocyclic
carboxylic acid in the solution is usually 5-70% by weight,
preferably 10-30% by weight.
[0018] In the gas-phase catalytic reaction of the present
invention, an inert gas such as nitrogen, helium and water vapor
may be used as a diluent. Among the inert gas, nitrogen is
preferred. When a diluent is used, amount of the diluent is usually
0.1-100 mol, preferably 1-40 mol per 1 mol of the heterocyclic
carboxylic acid.
[0019] The gas-phase catalytic reaction of the present invention
can be conducted in either a fixed-bed reactor or a fluidized-bed
reactor. When a fixed-bed reactor is used, the catalyst of the
present invention is packed in a reactor tube and the portion in
the tube where the catalyst is packed (catalyst packed portion) is
heated usually at 250-550.degree. C., preferably at 300-500.degree.
C. Thereafter, a heterocyclic carboxylic acid or a solution
dissolving a heterocyclic carboxylic acid In a solvent and ammonia,
and a diluent if required, are fed to the catalyst packed portion
to conduct a gas-phase catalytic reaction. Liquid hourly space
velocity of the heterocyclic carboxylic acid (hereinafter, referred
to as LHSV)is usually 0.001-5.0 g/(ml-catalyst-hr), preferably
0.01-2.0 g/(ml-catalyst-hr). Space velocity of the mixed gas of a
heterocyclic carboxylic acid, ammonia and optional ingredients,
that is solvent and diluent (hereinafter, referred to as SV) is
usually 30-10000 hr.sup.-1, preferably 50-1000 hr.sup.-1. The
reaction of the present invention may be conducted under a reduced
pressure, atmospheric pressure or an elevated pressure.
[0020] The heterocyclic nitrile obtained by the reaction of the
present invention can be isolated, for example, according to the
following method.
[0021] A reaction product gas containing a heterocyclic nitrile
exited from a reactor is cooled to obtain a condensate containing a
heterocyclic nitrile, or the generated gas is introduced in a
suitable solvent to obtain a solution containing a heterocyclic
nitrile. From the condensate or the solution, the heterocyclic
nitrile can be isolated through a combination of unit operations
such as concentration and distillation.
[0022] Using a heterocyclic nitrile of the present invention as a
starting material, a heterocyclic aldehyde can be produced
effectively.
[0023] That is, a heterocyclic aldehyde can be produced by a method
comprising a gas-phase catalytic reaction of a heterocyclic
carboxylic acid or an ester thereof with ammonia in the presence of
a catalyst comprising an oxide of at least one element selected
from copper and zinc to produce a heterocyclic nitrile, and
[0024] a catalytic hydrogenation of the heterocyclic nitrile thus
produced in the presence of a hydrogenation catalyst and an acid in
an aqueous solvent.
[0025] The catalytic hydrogenation of the heterocyclic nitrile can
be conducted by charging a heterocyclic nitrile, an aqueous solvent
and a hydrogenation catalyst, and a copper salt if required, to a
reactor, and then conducting the reaction while stirring and
feeding hydrogen gas to maintain the hydrogen pressure at
1.0.times.10.sup.5-2.0.times.10.sup.6 Pa, preferably at
5.0.times.10.sup.5-1.0.times.10.sup.6 Pa. The reaction temperature
is usually at 10-50.degree. C., preferably at 20-40.degree. C. In
the reaction above, when absorption amount of hydrogen exceeds
about 1.1 times of theory, usually the absorption rate of hydrogen
becomes lowering. Then, feed of the hydrogen gas is stopped, and
the reaction is terminated.
[0026] Examples of the hydrogenation catalyst used in the present
invention include Raney catalyst such as Raney nickel and Raney
cobalt, rare metal catalyst such as ruthenium/carbon,
rhodium/carbon and platinum/carbon, and the like.
[0027] A hydrogenation catalyst treated with a copper salt can also
be used. In the case where a hydrogenation catalyst treated with a
copper salt is used, production of by-products can be suppressed
and yield of the heterocyclic aldehyde can be improved, comparing
to the case where a hydrogenation catalyst not treated with a
copper salt is used.
[0028] Among the hydrogenation catalysts, Raney nickel and Raney
nickel treated with a copper salt are particularly preferred. As
the copper salt, an aqueous solution of a copper salt is preferred
Examples of the copper salt include copper sulfate, copper
hydroxide, copper acetate and hydrates thereof. Amount of the
copper salt used for treating the hydrogenation catalyst is usually
10-80% by weight, preferably 20-70% by weight, based on the amount
of the hydrogenation catalyst.
[0029] The hydrogenation catalyst treated with a copper salt can be
easily obtained by various methods. For example, it can be obtained
by
[0030] a method where a hydrogenation catalyst available on the
market is dispersed in a copper salt solution and suspended, a
method where a copper salt is added on preparing a hydrogenation
catalyst according to a conventional method, or the like.
[0031] In a method where a suspension of the catalyst obtained, the
suspension is left as it is to sediment the catalyst and the
supernatant liquid is removed by decantation. Then, water is added
to the residue for washing the catalyst. The resulting mixture is
stirred, then left as it is, followed by decantation to remove the
supernatant liquid These steps for washing the catalyst are
repeated for several times to obtain a hydrogenation catalyst
treated with a copper salt.
[0032] In the catalytic hydrogenation of the heterocyclic nitrile,
amount of the hydrogenation catalyst is usually 1-50 parts by
weight, preferably 5-30 parts by weight, per 100 parts by weight of
the heterocyclic nitrile.
[0033] Even when the catalytic hydrogenation is conducted by using
a hydrogenation catalyst not treated with a copper salt, if a
copper salt is added to the reaction system, production of
by-products can be suppressed and yield of the heterocyclic
aldehyde can be improved, as the case where a hydrogenation
catalyst treated with a copper salt is used.
[0034] In the catalytic hydrogenation of the heterocyclic nitrite
in the method of the present invention for producing a heterocyclic
aldehyde, an acid is used for neutralizing ammonia produced in the
reaction. As the acid, either an inorganic acid or an organic acid
can be used. Examples of the inorganic acid include sulfuric acid
and phosphoric acid, and examples of the organic acid include
acetic acid The acid is used in an amount sufficient for
neutralizing the produced ammonia, Since 1 mol of ammonia is
produced from 1 mol of the heterocyclic nitrile, amount of the acid
is 1 equivalent or more, preferably 1-3 equivalents, per 1 mol of
the heterocyclic nitrile.
[0035] If the amount of acid is smaller than 1 equivalent,
neutralization of ammonia becomes insufficient and yield of the
heterocyclic aldehyde lowers due to the reaction of the ammonia and
the heterocyclic aldehyde.
[0036] In the catalytic hydrogenation of the heterocyclic nitrile,
1 mol of water is reacted with 1 mol of the heterocyclic nitrile.
Therefore, the reaction is conducted in the presence of water In an
amount of 1 mol or more per 1 mol of the heterocyclic nitrile.
Usually, water is used as the reaction solvent, although a mixture
of water of the required amount and a water soluble solvent can be
used. Examples of the water soluble solvent include alcohol such as
methanol and ethanol. Amount of the aqueous solvent, water or a
mixed solvent containing water, is usually 1-15 parts by weight,
preferably 3-13 parts by weight, per 1 part by weight of the
heterocyclic nitrile.
[0037] The heterocyclic aldehyde produced in the reaction can
easily isolated and purified by removing the catalyst by filtration
of the reaction mixture after termination of the reaction and
adding an alkali to the filtrate for neutralization, followed by an
extraction, distillation or the like.
[0038] The following examples further illustrate the present
invention in more detail. The examples should not be construed to
limit the scope of the present invention.
[0039] In the examples, conversion, yield and selectivity ratio are
calculated according to the following definitions.
[0040] Conversion (%) ={(molar amount of reacted heterocyclic
carboxylic acid)/(molar amount of fed heterocyclic carboxylic
acid)}.multidot.100
[0041] Yield (%) ={(molar amount of a product, e.x. heterocyclic
nitrile, produced by the reaction)/(molar amount of fed
heterocyclic carboxylic acid)}.multidot.100
[0042] selectivity ratio (%) ={(molar amount of a product, e.x.
heterocyclic nitrile, produced by the reaction)/(molar amount of
reacted heterocyclic carboxylic acid)}.multidot.100
EXAMPLE 1
[0043] As a catalyst, tablet of copper oxide and zinc oxide (6.4 mm
3.2 mm, copper oxide/zinc oxide={fraction (33/65)} by weight) was
used. In a reactor made of Pyrex glass and having the inside
diameter of 18 mm was packed 14.0 ml of the catalyst, and the
catalyst packed portion of the reactor was heated to 320.degree. C.
To the catalyst packed portion, a mixture of methyl
6-methylnicotinate and toluene in a molar ratio of 1:4 and ammonia
were fed at feeding rates of 0.07 g/minute and 6.3 ml/minute (2
times in mol of the feeding rate of methyl 6-methylnicotinate),
respectively. The reaction product gas exited from the reactor tube
was introduced in 100 ml of ethanol for 25 minutes to dissolve
soluble ingredients contained in the generated gas in the ethanol.
The solution thus obtained was analyzed with a gas-chromatography.
From the analysis results, the following results were obtained.
%
1 Conversion of methyl 6-methyl nicotinate 82.1 Yield of
2-methyl-5-cyano-pyridine 67.9% Selectivity ratio of
2-methyl-5-cyano- 82.7% pyridine Yield of 2-picoline 3.3%
Selectivity ratio of 2-picoline 4.1%. Recovering ratio of toluene
was 93.7%.
EXAMPLE 2
[0044] The same reaction and analysis as in Example 1 were
conducted except that a feeding rate of ammonia was changed to 12.6
ml/minute (4 times in mol of the feeding rate of methyl
6-methylnicotinate). From the analysis results, the following
results were obtained.
2 Conversion of methyl 6-methyl nicotinate 90.2% Yield of
2-methyl-5-cyano-pyridine 78.1% Selectivity ratio of
2-methyl-5-cyano- 86.6% pyridine Yield of 2-picoline 2.1%
Selectivity ratio of 2-picoline 2.4%. Recovering ratio of toluene
was 93.3%.
EXAMPLE 3
[0045] The same reaction and analysis as in Example 1 were
conducted except that a feeding rate of ammonia was changed to 25.2
ml/minute (8 times in mol of the feeding rate of methyl
6-methylnicotinate). From the analysis results, the following
results were obtained.
3 Conversion of methyl 6-methyl nicotinate 96.5% Yield of
2-methyl-5-cyano-pyridine 83.9% Selectivity ratio of
2-methyl-5-cyano- 86.9% pyridine Yield of 2-picoline 0% Selectivity
ratio of 2-picoline 0%. Recovering ratio of toluene was 91.6%.
EXAMPLE 4
[0046] As a catalyst, tablet of copper oxide and zinc oxide (6.4
mm.times.3.2 mm, copper oxide/zinc oxide={fraction (42/47)} by
weight) was used. In a reactor made of Pyrex glass and having the
inside diameter of 18 mm was packed 14.0 ml of the catalyst, and
the catalyst packed portion of the reactor was heated to
320.degree. C. To the catalyst packed portion, a mixture of methyl
6-methylnicotinate and toluene in a molar ratio of 1:4 and ammonia
were fed at feeding rates of 0.07 g/minute and 6.3 ml/minute (2
times in mol of the feeding rate of methyl 6-methylnicotinate),
respectively. The reaction product gas exited from the reactor tube
was introduced in 100 ml of ethanol for 25 minutes to dissolve
soluble ingredients contained in the generated gas in the ethanol.
The solution thus obtained was analyzed with a gas-chromatography.
From the analysis results, the following results were obtained.
4 Conversion of methyl 6-methyl nicotinate 96.5% Yield of
2-methyl-5-cyano-pyridine 79.3% Selectivity ratio of
2-methyl-5-cyano- 82.2% pyridine Yield of 2-picoline 6.9%
Selectivity ratio of 2-picoline 7.2%. Recovering ratio of toluene
was 95.0%.
EXAMPLE 5
[0047] In an autoclave were charged 59.1 g (0.50 mol) of
2-methyl-5-cyanopyridine, 245.0 g (0.75 mol as sulfuric acid) of
30% aqueous sulfuric acid solution, 5.9 g of Raney nickel (Catalyst
R-101, manufactured by Nikkou Rika Co., Ltd.) and 1.8 g of copper
sulfate pentahydrate. Keeping the hydrogen-pressure at 0.7 M Pa by
feeding hydrogen from an inlet tube into the autoclave, reaction
was conducted at 35.degree. C. When absorption amount of hydrogen
reached to 107-110% of theory, the feed of hydrogen was stopped-
The reaction time was 4.5 hours. The catalyst was removed by
filtration and the filtrate was analyzed with a high performance
liquid chromatography. Prom the analysis results, the following
results were obtained.
5 Yield of 2-methyl-5-pyridinecarbaldehyde 86.8% Yield of
2-methyl-5-pyridinemethanol 1.8% Yield of
2-methyl-5-pyridinemethaneamine 9.8% 2-methyl-5-cyanopyridine was
not detected.
EXAMPLE 6
[0048] Example 5 was repeated except that amount of copper sulfate
pentahydrate was changed from 1.8 g to 3.6 g. The reaction time was
15 hours.
[0049] The following results were obtained.
6 Yield of 2-methyl-5-pyridinecarbaldehyde 83.9% Yield of
2-methyl-5-pyridinemethanol 3.2% Yield of
2-methyl-5-pyridinemethaneamine 9.8% 2-methyl-5-cyanopyridine was
not detected.
EXAMPLE 7
[0050] Under nitrogen atmosphere, 8-36 g of Raney nickel (Catalyst
R-101, manufactured by Nikkou Rika Co., Ltd.) was added to 250 g of
1% by weight aqueous solution of copper sulfate pentahydrate, and
the resulting mixture was stirred for 30 minutes at room
temperature. Then, the mixture, suspension, was left as it was to
sediment the catalyst and the supernatant liquid was removed. The
catalyst was washed by adding 100 ml of water to the residue,
stirring the resulting mixture, then leaving it as it was to
sediment the catalyst and removing the supernatant liquid. This
washing step was repeated 5 times in total to obtain Raney nickel
catalyst treated with a copper salt solution,
[0051] In an autoclave were charged 83.6 g (0.70 mol) of
2-methyl-5-cyanopyridine, 514.6 g (1.05 mol as sulfuric acid) of
20% aqueous sulfuric acid solution, 8.36 g of the Raney nickel
catalyst treated with a copper salt solution obtained above.
Keeping the hydrogen-pressure at 0.7 M Pa by feeding hydrogen from
an inlet tube into the autoclave, reaction was conducted at
25.degree. C. When absorption amount of hydrogen reached to 112% of
theory, the feed of hydrogen was stopped to terminate the reaction.
The reaction time was 9.5 hours. The catalyst was removed by
filtration and the filtrate was analyzed with a high performance
liquid chromatography. From the analysis results, the following
results were obtained.
7 Yield of 2-methyl-5-pyridinecarbaldehyde 84.1% Yield of
2-methyl-5-pyridinemethanol 0.5% Yield of
2-methyl-5-pyridinemethaneamine 5.0% 2-methyl-5-cyanopyridine was
not detected.
* * * * *