U.S. patent application number 10/160356 was filed with the patent office on 2002-12-05 for process for producing an alicyclic unsaturated alcohol.
Invention is credited to Fujitani, Kango, Kihara, Yoshihiro, Okumura, Koichi, Tanigawa, Hiroto, Uenoya, Masaya.
Application Number | 20020183564 10/160356 |
Document ID | / |
Family ID | 19006482 |
Filed Date | 2002-12-05 |
United States Patent
Application |
20020183564 |
Kind Code |
A1 |
Tanigawa, Hiroto ; et
al. |
December 5, 2002 |
PROCESS FOR PRODUCING AN ALICYCLIC UNSATURATED ALCOHOL
Abstract
An alicyclic unsaturated alcohol (for example, tetrahydrobenzyl
alcohol) having the purity of 99% by weight or more, the water
content of 0.1% by weight or less and the acid value of 0.1 mg
KOH/g or less can be produced, with high selectivity, by
hydrogenating using an unsaturated cyclic aldehyde having the acid
value of 10 mg KOH/g or less as a raw material; terminating the
hydrogenation in the conversion of 70 to 99.8%; and rectifying the
reaction product containing the unreacted unsaturated cyclic
aldehyde. The high purity alicyclic unsaturated alcohol is useful
as raw material chemicals for synthesizing drugs, agricultural
chemicals, perfumes, and dyes etc.
Inventors: |
Tanigawa, Hiroto;
(Hiroshima, JP) ; Okumura, Koichi; (Matsudo-shi,
JP) ; Uenoya, Masaya; (Fuabashi-shi, JP) ;
Fujitani, Kango; (Fushimi-ku, JP) ; Kihara,
Yoshihiro; (Fushimi-ku, JP) |
Correspondence
Address: |
MORGAN & FINNEGAN, L.L.P.
345 Park Avenue
New York
NY
10154-0053
US
|
Family ID: |
19006482 |
Appl. No.: |
10/160356 |
Filed: |
May 30, 2002 |
Current U.S.
Class: |
568/826 |
Current CPC
Class: |
C07C 29/141 20130101;
C07C 29/141 20130101; C07C 33/22 20130101 |
Class at
Publication: |
568/826 |
International
Class: |
C07C 029/141 |
Foreign Application Data
Date |
Code |
Application Number |
May 30, 2001 |
JP |
2001-163531 |
Claims
What is claimed is:
1. A process for producing an alicyclic unsaturated alcohol having
the purity of 99% by weight or more, the water content of 0.1% by
weight or less and the acid value of 0.1 mg KOH/g or less, the
process comprising: (1) hydrogenating using an unsaturated cyclic
aldehyde having the acid value of 10 mg KOH/g or less as a raw
material; (2) terminating the hydrogenation in the conversion of 70
to 99.8%; and (3) rectifying a reaction product containing the
unreacted unsaturated cyclic aldehyde; in the production of the
alicyclic unsaturated alcohol by hydrogenating the unsaturated
cyclic aldehyde represented by the following general formula (1):
3wherein R represents a hydrogen or a methyl group, in the presence
of a catalyst.
2. A process for producing a tetrahydrobenzyl alcohol having the
purity of 99% by weight or more, the water content of 0.1% by
weight or less and the acid value of 0.1 mg KOH/g or less, the
process comprising: (1) hydrogenating using tetrahydrobenzaldehyde
having the acid value of 10 mg KOH/g or less as a raw material; (2)
terminating the hydrogenation in the conversion of 70 to 99.8%; and
(3) rectifying a reaction product containing the unreacted
tetrahydrobenzaldehyde; in the production of the tetrahydrobenzyl
alcohol by hydrogenating tetrahydrobenzaldehyde in the presence of
a catalyst.
3. A method according to claim 1 or 2, wherein the catalyst used is
copper, copper-zinc, copper-chromium, copper-zinc-chromium or one
or more mixed catalysts selected from the oxides thereof, or a
modified catalyst thereof with molybdenum, tungsten, magnesium,
barium, aluminum, calcium, zirconium, manganese, and nickel or the
oxides thereof.
4. A method according to claim 1 or 2, wherein the hydrogenation is
performed under pressure of hydrogen gas of 0.1 to 8 MPa.
5. A tetrahydrobenzyl alcohol having the purity of 99.0% by weight
or more, the water content of 0.1% by weight or less and the acid
value of 0.1 mg KOH/g or less obtained by using the producing
method according to claim 2.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a process for producing an
alicyclic unsaturated alcohol and a high purity tetrahydrobenzyl
alcohol. Specifically, the present invention relates to a process
for producing an alicyclic unsaturated alcohol used for a great
variety of industrial applications, for example, as raw chemicals
for synthesizing drugs, agricultural chemicals, perfumes, dyes,
etc. More specifically, the present invention relates to a process
for producing, with high selectivity, an appropriate alicyclic
unsaturated alcohol such as tetrahydrobenzyl alcohol useful as an
intermediate raw material for epoxy resins, and the like, and a
high purity tetrahydrobenzyl alcohol having a low acid value and a
low water content.
[0003] 2. Description of the Related Art
[0004] As a process for producing an alicyclic unsaturated alcohol
such as tetrahydrobenzyl alcohol by hydrogenating an unsaturated
cyclic aldehyde such as tetrahydrobenzaldehyde, that is, a process
for obtaining an alicyclic unsaturated alcohol by selectively
reducing a carbonyl moiety in the unsaturated cyclic aldehyde,
conventionally, the process for obtaining a corresponding
unsaturated alcohol using a reducing reagent, for example, by
reducing using lithiumaluminumhydride (A. Guiotto. et al., Farmaco.
Ed. Sci. 72 (12), 1045-52 (1972)), or by reducing using sodium
borohydride (Neth. Appl. 790242 (1979. 9. 18)) is known.
[0005] The method using LiAlH.sub.4, NaBH.sub.4, or the like as a
reducing reagent is one which is capable of producing, with
high-selectivity, the alicyclic unsaturated alcohol, for example,
in which the conversion is 98 mol % or more, the selectivity of the
desired alicyclic unsaturated alcohol is 97 to 98 mol %, the
by-produced alicyclic saturated alcohol is 2 to 3 mol %, and a
little saturated cyclic aldehyde is produced. However, the method
is very disadvantageous for the industrial applications, since the
reducing reagent used is very expensive and a large quantity of the
reducing reagent must be used. Also, a large quantity of waste
water is generated, because the method requires a large quantity of
water for the reaction. Thus, there has been the problem of
requiring very high cost for disposing of waste water. Moreover,
the method has had the disadvantage in that it is difficult to
apply the method to the industrial application because of its
economic inferiority. Therefore, the method of synthesizing the
alicyclic unsaturated alcohol without using such reducing reagents
is sought.
[0006] Furthermore, the method of performing a hydrogen migration
reaction using tetrahydrobenzaldehyde and alcohols as well as a
catalyst is known (JP 63-275538 A).
[0007] Although the above-mentioned method can achieve the high
selectivity, there is a problem in that the method requires
aluminum alcoholate and alcohols of more than equimolar amount of
the main raw material and also an equimolar amount of ketones is
by-produced.
[0008] Therefore, the various methods of hydrogenating using a
catalyst have been investigated as the method of synthesizing the
alicyclic unsaturated alcohol without using the reducing reagents.
For example, the method of hydrogenating using a copper-chromite
catalyst, for example, the reaction using a copper-chromite as a
catalyst under compression of hydrogen gas (Neth. Appl. 6,603,211
(1966. 9. 13)) and the reaction using a copper-chromite as a
catalyst as well as cyclohexane, tetrahydrofuran as a solvent under
compression of hydrogen gas (Ger. 1,101,409 (1961. 3 . 9.), J.
Falbe. et. al., Chem. Ber. 98 (6), 1928-37 (1965)), and the method
of hydrogenating using catalysts carried by Co, Rh--Sn, Ru--Sn, or
the like on alumina, silica, zeolite, or the like under compression
of hydrogen gas, for example, "The synthesis of crotyl alcohol by
selectively hydrogenating crotonaldehyde using an alumina-carried
bimetallic catalyst" (Nippon kagaku kaishi (Japanese), 1994 (5),
487-489: SAITAMA UNIVERSITY), and "The selective vapor phase
hydrogenation of crotonaldehyde on an Ru--Sn-carried catalyst" (the
76th Catalyst Society of Japan Meetings, 3E15,228 (1995) : KOBE
UNIVERSITY), are known.
[0009] However, the methods using those catalysts are still
insufficient for selectivity of the desired unsaturated alcohol,
and there is a problem in that the saturated cyclic aldehyde and
alicyclic saturated alcohol, which are by-products, are produced in
an amount of more than that of the desired product.
[0010] As the method of improving the above-mentioned method, the
reaction using an alumina-carried cobalt catalyst under compression
of hydrogen gas is known (JP 10-236995 A). Inthemethod, the
catalyst obtained by adding to the above-mentioned alumina-carried
cobalt catalyst containing the second metals (Pt, Ru, Fe, Cu, Rh,
etc.) is used to hydrogenate an unsaturated aldehyde using a polar
solvent such as an alcohol, and then, the carbonyl moiety in the
unsaturated aldehyde having a double bond in the molecule is
selectively hydrogenated to selectively produce a corresponding
unsaturated alcohol.
[0011] However, the hydrogenation according to the above-mentioned
method indispensably requires the presence of the polar solvent,
and has poor productivity and is not sufficient for the industrial
application.
[0012] When tetrahydrobenzyl alcohol as the alicyclic unsaturated
alcohol is used as an example, impurities at the time of production
of the alcohol include tetrahydrobenzaldehyde
(3-cyclohexenecarboaldehyde) which is a raw material, and
hexahydrobenzyl alcohol, cycrohexanecarboaldehyde, and the like,
which are by-products. In general, those impurities are
industrially separated by rectification.
[0013] The boiling points of the impurities contained in the
desired unsaturated alcohol (3-cyclohexenemethanol; boiling point:
183.degree. C.) are 163.degree. C. (for
3-cyclohexenecarboaldehyde), 161.degree. C. (for
cyclohexanecarboaldehyde), and 181.degree. C. (for
cyclohexanemethanol).
[0014] The boiling point of the unsaturated cyclic aldehyde as the
raw material which is one of the impurities, is relatively low
compared to the alicyclic unsaturated alcohol, and they have the
difference of boiling points of from 20 to 30.degree. C. Thus, they
can be separated by rectification. However, the boiling point of
the alicyclic saturated alcohol which is another by-product, is
almost equal to that of the alicyclic unsaturated alcohol. As a
result, the industrial-scale separation is substantially
impossible, and thus, the by-products, which are difficult to
separate, are provided with being contained in the article.
[0015] However, when the above-mentioned unsaturated alcohol is
used as a perfume, the regulation on the concentration of the
saturated alcohol which is an impurity is very strict, and it is
pointed out that even the product having the overspeck of 0.1 mol %
can not be the article.
[0016] Moreover, the alicyclic unsaturated alcohol such as
tetrahydrobenzyl alcohol may be used as raw materials for polymers
by being subjected to the modification described in the following
a) to d), for example.
[0017] a) esterifying a hydroxyl group in the alicyclic unsaturated
alcohol with an ethylenically unsaturated acid such as acrylic acid
and/or methacrylic acid;
[0018] b) esterifying a hydroxyl group in the alicyclic unsaturated
alcohol with an ethylenically unsaturated acid such as acrylic acid
and/or methacrylic acid, and epoxidizing the double bond;
[0019] c) converting the double bond in the alicyclic unsaturated
alcohol to a hydroxyl group, and esterifying the produced hydroxyl
group with the above-mentioned ethylenically unsaturated acid, or
the like to form diester or triester; or
[0020] d) epoxidizing the double bond in the alicyclic unsaturated
alcohol, and further converting the hydroxyl group to glycidyl
group.
[0021] In the above-mentioned case, the low purity due to the
remaining alicyclic saturated alcohol as well as saturated and
unsaturated aldehyde, and the like causes those impurities to
remain as the unreacted components in polymerization, and thus it
is not preferable.
[0022] Furthermore, much water content inhibits the reaction when
the double bond is epoxidized, which is very not preferable.
[0023] Moreover, the free carboxylic acids which contribute to acid
value have a different odor from that of the desired product and
they are the reactive impurities, thus it is not preferable to
contain the free acids in any way. Therefore, the reduction of the
free acids is required.
SUMMARY OF THE INVENTION
[0024] In view of the above-mentioned problems, it is required that
an alicyclic unsaturated alcohol which is a final product has high
purity. Thus, an object of the present invention is to provide a
process for producing, with high-selectivity, a high purity
alicyclic unsaturated alcohol having a purity of 99% by weight or
more, a water content of 0.1% by weight or less and an acid value
of 0.1 mg KOH/g or less.
[0025] To achieve the above object, the present inventors have
intensely studied hydrogenation of an unsaturated cyclic aldehyde
in the presence of a catalyst. As a result, the inventors have
found that although the alicyclic unsaturated alcohol is usually
produced in an early stage of the reaction under the condition of
using the selected catalyst useful for the present invention, the
produced alicyclic unsaturated alcohol is converted to the further
hydrogenated alicyclic saturated alcohol in a later stage of the
reaction. Also, the inventors have found that it is very important
that the by-production of the alicyclic saturated alcohol is
controlled as significantly as possible, since the separation of
the alicyclic saturated alcohol is very difficulties described
above. Therefore, the inventors have found that it can be extremely
important that the hydrogenation is terminated before the alicyclic
saturated alcohol is produced, and that the unreacted unsaturated
cyclic aldehyde is cut in a separation step such as
rectification.
[0026] Moreover, the inventors have confirmed that a
copper-chromite catalyst has particularly high ability for the
selective hydrogenation of a carbonyl moiety in the reduction of
the unsaturated cyclic aldehyde and the hydrogenation of the double
bond, and have found that the hydrogenation is terminated in a
stage with a strictly controlled degree of reaction by strictly
controlling the reaction condition, thereby inhibiting or
inactivating the hydrogenation of the double bond to obtain the
desired alicyclic unsaturated alcohol with the high selectivity and
the high yield. As a result, a composition, which it is easy to
separate by rectification, is provided, and the high purity
alicyclic unsaturated alcohol with the high yield is produced.
Thus, the present invention has been completed.
[0027] According to a first aspect of the present invention, there
is provided a process for producing an alicyclic unsaturated
alcohol having the purity of 99% by weight or more, the water
content of 0.1% by weight or less and the acid value of 0.1 mg
KOH/g or less, characterized by comprising:
[0028] (1) hydrogenating using an unsaturated cyclic aldehyde
having the acid value of 10 mg KOH/g or less as a raw material;
[0029] (2) terminating the hydrogenation in the conversion of 70 to
99.8%; and
[0030] (3) rectifying a reaction product containing the unreacted
unsaturated cyclic aldehyde; in the production of an alicyclic
unsaturated alcohol by hydrogenating the unsaturated cyclic
aldehyde represented by the following general formula (1) 1
[0031] wherein R represents a hydrogen or a methyl group, in the
presence of a catalyst.
[0032] According to a second aspect of the present invention, there
is provided a process for producing a tetrahydrobenzyl alcohol
having the purity of 99% by weight or more, the water content of
0.1% by weight or less and the acid value of 0.1 mg KOH/g or less,
characterized by comprising:
[0033] (1) hydrogenating using a tetrahydrobenzaldehyde having the
acid value of 10 mg KOH/g or less as a raw material;
[0034] (2) terminating the hydrogenation in the conversion of 70 to
99.8%; and
[0035] (3) rectifying a reaction product containing the unreacted
tetrahydrobenzaldehyde;
[0036] in the production of tetrahydrobenzyl alcohol by
hydrogenating tetrahydrobenzaldehyde in the presence of a
catalyst.
[0037] According to a third aspect of the present invention, in the
first or second aspect of the present invention, there is provided
a method, characterized in that the catalyst used is copper,
copper-zinc, copper-chromium, copper-zinc-chromium or one or more
mixed catalysts selected from the oxides thereof, or a modified
product thereof with molybdenum, tungsten, magnesium, barium,
aluminum, calcium, zirconium, manganese, nickel or the oxides
thereof.
[0038] According to a fourth aspect of the present invention, in a
first or second aspect of the present invention, there is provided
a method, characterized in that the hydrogenation is performed
under pressure of hydrogen gas of 0.1 to 8 MPa.
[0039] According to a fifth aspect of the present invention, there
is provided a tetrahydrobenzyl alcohol having the purity of 99% by
weight or more, the water content of 0.1% by the weight or less and
the acid value of 0.1 mg KOH/g or less, obtained by using the
method according to the second aspect of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0040] The alicyclic unsaturated alcohol obtained by the production
method according to the present invention is used as raw materials
for drugs, agricultural chemicals, perfumes, dyes, monomers for
polymers, and the like.
[0041] The present invention is a process for producing an
alicyclic unsaturated alcohol having the purity of 99% by weight or
more, the water content of 0.1% by weight or less and the acid
value of 0.1 mg KOH/g or less, characterized by comprising:
[0042] (1) hydrogenating using an unsaturated cyclic aldehyde
having the acid value of 10 mg KOH/g or less as raw material;
[0043] (2) terminating the hydrogenation in the conversion of 70 to
99.8%, preferably 80 to 99.8%, more preferably 90 to 99.8%; and
[0044] (3) rectifying a reaction product containing the unreacted
unsaturated cyclic aldehyde;
[0045] in the production of the alicyclic unsaturated alcohol by
hydrogenating the unsaturated cyclic aldehyde represented by the
following general formula (1) 2
[0046] wherein R represents a hydrogen or a methyl group, in the
presence of a catalyst.
[0047] The unsaturated cyclic aldehyde used for the present
invention may be synthesized or naturally occurring products. In
the case of the synthesized aldehyde, tetrahydrobenzaldehyde
(3-cyclohexenecarboaldehyde, in other words, 1, 2, 3,
6-tetrahydrobenzaldehyde), which is represented by the formula (1)
wherein R is a hydrogen, is used in many cases because of the easy
availability of the raw material.
[0048] The acid value of the raw material is 10 mg KOH/g or less,
preferably 1 mg KOH/g or less.
[0049] The acid value of the raw material of more than 10 mg KOH/g
causes the copper component in the catalyst to elute at the
hydrogenation step to deteriorate the catalyst. Moreover, the
various problems are caused that the eluted copper is reduced with
hydrogen gas and is re-deposited inside the reaction tube to form
the mirror-like metal coating, or the eluted copper forms the metal
coating reduced with the remaining aldehyde on the bottom of the
distilling column, and the like. When the acid value of the raw
material is more than 10 mg KOH/g, the acid value of the obtained
alicyclic unsaturated alcohol becomes greater even though the
conversion is controlled within the range of 70 to 99.8%. Thus,
this is not preferable for raw materials for synthesizing drugs,
agricultural chemicals, perfumes, dyes etc.
[0050] Also, since the free carboxylic acid exists greatly after
the hydrogenation step, the operation of continuing to rectify
tetrahydrobenzyl alcohol which is a main fraction in the state of
high reflux ratio is required so as not to distill the free
carboxylic acid in the rectification step. Thus, the productivity
is remarkably reduced.
[0051] The examples of the catalyst used for the present invention
include copper, copper-zinc, copper-chromium, copper-zinc-chromium
or one or more mixed catalysts selected from the oxides thereof, or
modified products thereof with molybdenum, tungsten, magnesium,
barium, aluminum, calcium, zirconium, manganese, nickel or the
oxides thereof.
[0052] Specific examples of preferred catalysts include
copper-chromium oxide, copper-zinc oxide, copper-zinc-chromium
oxide, copper-chromium-magnesium oxide, copper-chromium-barium
oxide, copper-chromium-manganese oxide,
copper-chromium-magnesium-manganese oxide,
copper-chromium-magnesium-barium oxide, copper-chromium-manganese--
barium oxide, copper-chromium-magnesium-manganese-barium oxide,
copper-zinc-aluminum oxide, copper-zinc-magnesium oxide,
copper-zinc-barium oxide, copper-zinc-manganese oxide,
copper-zinc-magnesium-manganese oxide, copper-zinc-magnesium-barium
oxide, copper-zinc-manganese-barium oxide,
copper-zinc-magnesium-manganes- e-barium oxide. As those catalysts,
the commercially available catalysts such as N203, N203S, N203SD,
N203SDB (manufactured by Nikki Chemical Co., Ltd.), Cu-0202P,
Cu-1106P, Cu-1160P, Cu-1800P, Cu-1850P, Cu-1950P, Cu-0891P
manufactured by N.E Chemcat Corp.), and CB-2, C-5A, C-100, C-700,
C-900 (manufactured by Sakai Chemical Industries, Ltd.) can be
used.
[0053] Moreover, in addition to the above-mentioned metal and metal
oxides, the catalysts, which are, added with the formation aids
such as diatomaceous earth (kieselguhr), clay and graphite, or the
carried catalysts of the above-mentioned metal oxide on the carrier
such as alumina and silica can be used.
[0054] Those catalysts can be used as they are. Also, a suitable
activating process such as the reduction process prior to use of
the catalyst is preferably performed.
[0055] The amount used of those catalysts is 0.001% weight or more,
preferably 0-1 to 10% by weight with respect to the unsaturated
cyclic aldehyde which is a starting material. When the usage of the
catalyst is 0.001% by weight or less, it is impractical since the
reaction rate is very slow. To the contrary, when the catalyst of
10% by weight or more is used, it is not economical since the
reaction rate is not improved.
[0056] The hydrogenation according to the present invention may be
any of a batch process, a semi-batch process or a continuous
process. A mixing tank, a tubular type reactor, or the like can be
used as a reactor.
[0057] The above-mentioned catalyst is usually in a solid state or
powdery. When the method for the production is a batch process, the
solid-state or powdery catalyst is introduced into the reactor
charged with the unsaturated cyclic aldehyde, and the reactor is
replaced with an inert gas such as nitrogen gas, and is then filled
with hydrogen gas. Thus the hydrogenation is carried out.
[0058] When the method is a continuous process, the unsaturated
cyclic aldehyde is mixed with the catalyst in a premixing tank, and
the mixture is continuously entered into the reactor for
hydrogenation. Thus the reaction is carried out.
[0059] When a fixed bed reactor is used, a tablet type solid
catalyst is charged into a tubular type reactor to use.
[0060] The production process according to the present invention
does not particularly require a solvent, but, a solvent may be
optionally used. The solvents selected are not particularly limited
as long as the solvents are inactive to the reaction, and can
dissolve the raw material and the alicyclic unsaturated alcohol
which is a reaction product and also can be separated by
rectification. As the solvent, a primary alcohol having 2 to 6
carbon atoms, ethers, and like are selected.
[0061] The reaction temperature for the hydrogenation according to
the present invention is not particularly limited, but, too high
reaction temperature causes low selectivity and produces quantities
of saturated alcohol which can not be separated. As a result, the
saturated alcohol remains in a final product, and thus the
industrial purity can not be satisfied. Moreover, too high
temperature causes the dehydration to increase water content in the
reaction product. Thus, the hydrogenation is preferably performed
at 30 to 200.degree. C., more preferably 100 to 180.degree. C.
[0062] The pressure for the hydrogenation according to the present
invention is desirably within the range of 0.1 to 8 MPa, more
preferably 0.5 to 5 MPa. When the pressure in the hydrogenation is
too low, the reaction can not proceed. To the contrary, too high
pressure is not preferred because the selectivity between the
reduction of the aldehyde and the hydrogenation of the double bond
is reduced.
[0063] The hydrogenation is terminated in the conversion of 70 to
99.8%. Terminating the reaction in the conversion of 70 to 99.8%,
preferably 80 to 99.8%, more preferably 90 to 99.8% can achieve the
required selectivity in the reaction and the productivity. When the
reaction is terminated in the conversion of lower than 70%, the
productivity is reduced, and when the conversion is greater than
99.8%, a quantity of cyclohexyl alcohol which is an unnecessary
product by the excess reaction is produced, which is not preferred.
The termination point in the hydrogenation can be determined by
analyzing the remaining unsaturated cyclic aldehyde in the reaction
system.
[0064] After the hydrogenation is completed, the impurities are
separated by rectification. A rectifying column having the
theoretical plate number of 5 to 30 plate numbers is sufficient to
separate, and preferably, a rectifying column having the
theoretical plate number of 10 to 25plate numbers is used to
separate. In general, a rectifying column having the theoretical
plate number of 20 plate numbers is used. The rectifying
temperature and the degree of the reduced pressure vary depending
on the alicyclic unsaturated alcohol and the impurities, but in the
case of tetrahydrobenzyl alcohol, the rectification is preferably
carried out under the condition of the temperature at the column
top of 80 to 200.degree. C. and the degree of the reduced pressure
of 10 to 300 mmHg,.
[0065] The thus obtained alicyclic unsaturated alcohol has the
purity of 99% by weight or more, the water content of 0.1% by
weight or less and the acid value of 0.1 mg KOH/g or less,
preferably 0.05 mg KOH/g or less.
EXAMPLES
[0066] The present invention will be illustrated in detail by the
following examples, but the present invention is not limited by the
examples. As for the following "catalyst", the commercially
available product itself was conveniently used. The method for the
analysis was as described below. Gas chromatographic analysis
[0067] Column: DB-5 (capillary column); 30 m; inner diameter: 0.53
mm; thickness: 1.5 micron
[0068] Dodecane was used as an internal standard substance, and the
weight percentage of each component was calculated from the area
ratio of each component to the internal standard substance.
[0069] Water content: Karl Fischer technique (% by weight) Acid
value: basic analysis method for oils & fats (mg KOH/g)
Example 1
[0070] 50 g of tetrahydrobenzaldehyde (3-cyclohexenecarboaldehyde;
purity: 99.7% by weight; 0.5 mg KOH/g) and 0.5 g of copper-chromite
catalyst C-700 (manganese/magnesium-modified copper-chromite)
manufactured by Sakai Chemical Industries, Ltd. were introduced
into an autoclave made of stainless steel, which was equipped with
a stirrer, a thermometer and a pressure gauge, and the autoclave
was replaced with nitrogen and then filled with hydrogen. The
hydrogenation was performed at the temperature of 150.degree. C.
under the pressure of 3 MPa for 9 hours, and the reaction was
terminated in the conversion of 98.1% by purging hydrogen (the
reaction termination point was determined based on the amount of
the remaining tetrabenzaldehyde by gas chromatography analysis (The
same method was also used in the following Examples).
[0071] The composition of a crude reaction product by gas
chromatography analysis was 97.6% by weight of tetrahydrobenzyl
alcohol which is a target product, 1.9% by weight of
tetrahydrobenzaldehyde which is a raw material, 0.2% by weight of
hexahydrobenzyl alcohol and 0.3% by weight of unidentified
components.
[0072] The crude reaction product was placed into a laboratory
rectifying column having the theoretical plate number of 10 plate
numbers, and the rectification was carried out under the condition
of the temperature at the column top of 96 to 109.degree. C., the
degree of the reduced pressure of 23 to 44 mmHg and the reflux
ratio of 1 to obtain 46.5 g of a rectified product of
tetrahydrobenzyl alcohol (3-cyclohexenemethanol) (yield: 91.3%). It
was shown by the analysis that the rectified product had the water
content of 0.02% by weight, the acid value of 0.01 mg KOH/g, and
the purity by the gas chromatography analysis of 99.6% by
weight.
Example 2
[0073] The hydrogenation was performed by the same method as in the
Example 1 except that the copper-chromite catalyst was substituted
for 1850P (copper-chromite) manufactured by N. E. Chemcat Corp. The
reaction was terminated in the conversion of reaction of 98% by
purging hydrogen. The composition of a crude reaction product by
gas chromatography analysis was 97.4% by weight of tetrahydrobenzyl
alcohol which is a target product, 2.0% by weight of
tetrahydrobenzaldehyde which is a raw material, 0.3% by weight of
hexahydrobenzyl alcohol and 0.3% by weight of unidentified
components.
[0074] The rectification was carried out by the same method as in
the Example 1 to obtain 47.6 g of a rectified product (yield:
93.5%). It was shown by the analysis that the rectified product had
the water content of 0.03% by weight, the acid value of 0.01 mg
KOH/, and the purity by the gas chromatography analysis of 99.3% by
weight.
Example 3
[0075] The hydrogenation was performed by the same method as in the
Example 1 except that the copper-chromite catalyst was substituted
for N-203 (manganese-modified copper-chromite) manufactured by
Nikki Chemical Co., Ltd. The reaction was terminated in the
conversion of 96% by purging hydrogen. The composition of a crude
reaction product by gas chromatography analysis was 95.4% by weight
of tetrahydrobenzyl alcohol which is a target product, 4.0% by
weight of tetrahydrobenzaldehyde which is a raw material, 0.3% by
weight of hexahydrobenzyl alcohol and 0.3% by weight of
unidentified components.
[0076] The rectification was carried out by the same method as in
the Example 1 to obtain 46.2 g of a rectified product (yield:
90.8%). It was shown by the analysis that the rectified product had
the water content of 0.02% by weight, the acid value of 0.01 mg
KOH/g, and the purity by the gas chromatography analysis of 99.4%
by weight.
Example 4
[0077] The hydrogenation was performed by the same method as in the
Example 1 except that the reaction was terminated in the conversion
of 85.0%.
[0078] The composition of a crude reaction product by gas
chromatography analysis was 84.5% by weight of tetrahydrobenzyl
alcohol which is a target product, 15.0% by weight of
tetrahydrobenzaldehyde which is a raw material, 0.2% by weight of
hexahydrobenzyl alcohol and 0.3% by weight of unidentified
components.
[0079] The rectification was carried out by the same method as in
the Example 1 to obtain 38.9 g of a rectified product (yield:
76.4%). It was shown by the analysis that the rectified product had
the water content of 0.02% by weight, the acid value of 0.01 mg
KOH/g, and the purity by the gas chromatography analysis of 99.1%
by weight.
Example 5
[0080] The hydrogenation was performed by the same method as in the
Example 1 except that the reaction was terminated in the conversion
of 99.8%. The composition of a crude reaction product by gas
chromatography analysis was 99.1% by weight of tetrahydrobenzyl
alcohol which is a target product, 0.2% by weight of
tetrahydrobenzaldehyde which is a raw material, 0.7% by weight of
hexahydrobenzyl alcohol and 0.3% by weight of unidentified
components.
[0081] The rectification was carried out by the same method as in
the Example 1 to obtain 45.7 g of a rectified product (yield:
89.8%). It was shown by the analysis that the rectified product had
the water content of 0.02% by weight, the acid value of 0.01 mg
KOH/g, and the purity by the gas chromatography analysis of 99.1%
by weight.
Example 6
[0082] The hydrogenation was performed by the same method as in the
Example 1 except that a tetrahydrobenzyl alcohol having the purity
of 99.7% by weight and acid value of 3mg KOH/g was used. The
composition of a crude reaction product by gas chromatography
analysis was 97.4% by weight of tetrahydrobenzyl alcohol which is a
target product, 1.9% by weight of tetrahydrobenzaldehyde which is a
raw material, 0.2% by weight of hexahydrobenzyl alcohol and 0.5% by
weight of unidentified components.
[0083] The rectification was carried out by the same method as in
the Example 1 to obtain 45.6 g of a rectified product (yield:
91.2%). It was shown by the analysis that the rectified product had
the water content of 0.04% by weight, the acid value of 0.06 mg
KOH/g, and the purity by the gas chromatography analysis of 99.5%
by weight.
Example 7
[0084] The hydrogenation was performed by the same method as in the
Example 1 except that a tetrahydrobenzyl alcohol having the purity
of 99.7% by weight and acid value of 8mg KOH/g was used. The
composition of a crude reaction product by gas chromatography
analysis was 97.5% by weight of tetrahydrobenzyl alcohol which is a
target product, 1.9% by weight of tetrahydrobenzaldehyde which is a
raw material, 0.2% by weight of hexahydrobenzyl alcohol and 0.4% by
weight of unidentified components.
[0085] The rectification was carried out by the same method as in
the Example 1 to obtain 45.0 g of a rectified product (yield:
90.0%). It was shown by the analysis that the rectified product had
the water content of 0.06% by weight, the acid value of 0.08 mg
KOH/g, and the purity by the gas chromatography analysis of 99.3%
by weight.
Comparative Example 1
[0086] The hydrogenation was performed by the same method as in the
Example 1 except that the reaction was terminated in the conversion
of 67.5%.
[0087] The composition of a crude reaction product by gas
chromatography analysis was 66.0% by weight of tetrahydrobenzyl
alcohol which is a target product, 33.5% by weight of
tetrahydrobenzaldehyde which is a raw material, 0.2% by weight of
hexahydrobenzyl alcohol and 0.3% by weight of unidentified
components.
[0088] Then the rectification was carried out by the same method as
in the Example 1 to obtain 26.8 g of a rectified product of
tetrahydrobenzyl alcohol (3-cyclohexenemethanol) (yield: 52.6%). It
was shown by the analysis that the rectified product had the water
content of 0.02% by weight, the acid value of 0.01 mg KOH/g, and
the purity by the gas chromatography analysis of 98.6% by
weight.
Comparative Example 2
[0089] The hydrogenation was performed by the same method as in the
Example 1 except that the reaction was terminated in the degree of
reaction of 99.95%. The composition of a crude reaction product by
gas chromatography analysis was 94.8% by weight of tetrahydrobenzyl
alcohol which is a target product, 0.1% by weight of
tetrahydrobenzaldehyde which is a raw material, 5.0% by weight of
hexahydrobenzyl alcohol and 0.1% by weight of unidentified
components.
[0090] Then the rectification was carried out by the same method as
in the Example 1 to obtain 45.0 g of a rectified product (yield:
88.4%). It was shown by the analysis that the rectified product had
the water content of 0.02% by weight, the acid value of 0.01 mg
KOH/g, and the purity by the gas chromatography analysis of 94.8%
by weight. The rectified product contained 5.0% by weight of
hexahydrobenzyl alcohol.
Comparative Example 3
[0091] The hydrogenation was performed by the same method as in the
Example 1 except that the acid value of the raw material was 11.0
mg KOH/g. The reaction was terminated in the conversion of 98.1% by
purging hydrogen. The composition of a crude reaction product by
gas chromatography analysis was 97.6% by weight of tetrahydrobenzyl
alcohol which is a target product, 1.9% by weight of
tetrahydrobenzaldehyde which is a raw material, 0.2% by weight of
hexahydrobenzyl alcohol and 0.3% by weight of unidentified
components.
[0092] Then the rectification was carried out by the same method as
in the Example 1 to obtain 46.4 g of a rectified product (yield:
91.1%). It was shown by the analysis that the rectified product had
the water content of 0.02% by weight, the acid value of 0.5 mg
KOH/g, and the purity by the gas chromatography analysis of 99.5%
by weight. The considerable deposition of the metal derived from
the catalyst was observed inside the autoclave and in the bottom of
the distillation column.
[0093] According to the production process of the present
invention, the alicyclic unsaturated alcohol having the high
purity, low water content and low acid value can be produced with
high selectivity and high yield.
* * * * *