Note: Descriptions are shown in the official language in which they were submitted.
CA 02432664 2003-06-19
PROCESS FOR PRODUCING 3-METHYLTETRAHYDROFURAN, AND
PROCESS FOR PRODUCING AN INTERMEDIATE THEREOF
The present application has been divided out of Canadian
Patent Application Serial No. 2,308,555 filed May 16, 2000.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a process for producing
3-methyltetrahydrofuran, and processes for producing 3-hydroxy-
3-methyltetrahydrofuran and 3-methyldihydrofuran, which are
intermediates thereof. 3-methyltetrahydrofuran obtained by the
present invention is useful as a raw material of polyether polyol,
which is , for example , a component of a thermoplastic polyurethane ,
or a solvent. 3-hydroxy-3-methyltetrahydrofuran and 3-
methyldihydrofuran obtained by the present invention are useful as
raw materials of chemicals such as medicines or agricultural
chemicals.
Description of the Related Art:
As conventional processes for producing 3-
methyltetrahydrofuran, the following processes are known: (a) a
process of cyclodehydrating 2-methyl-1,4-butanediol [see Ind. Eng.
Chem. Res. , 33, pp. 444-447 (1994) ] , (b) a process of hydrogenating
methylsuccinic acid, using i.sopropanol as a hydrogen source, over
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hydrous zirconium oxide catalyst [see Bull. Chem. Soc. Jpn. , 65, pp.
262-266 ( 1992 ) ] , ( c ) a process of hydroformylating methallyl alcohol,
hydrogenating the resultant formylated product, and then
cyclodehydrating the hydrogenated product [see J. Prakt. Chem., 314,
pp. 840-850 (1972)], and (d) a process of hydrogenating 3-
methyl-3,4-epoxybutan-1-of in an acidic aqueous solution [see USP
3,956,318].
However, in the process (a), it is difficult to obtain 2-
methyl-1,4-butanediol industrially, which is a raw material. In the
process (b), preparing hydrous zirconium oxide catalyst is
complicated, and acetone is formed as by-product in an equivalent
to the amount of isopropano:L used as the hydrogen source. In the
process (c), a rhodium compound used as a catalyst for the
hydroformylation reaction is expensive. Moreover, methallyl
alcohol, which is a raw material, is not industrially produced so
that it is difficult to obtain the alcohol easily and economically.
In the process (d), 3-methyl-3,4-epoxybutan-1-of is not industrially
produced so that it is difficult to obtain the compound easily and
economically. Besides, under reaction conditions in the acidic
aqueous solution , the raw material tend to be hydrolyzed to produce
a triol as by-product, which is formed by ring-opening of the epoxy
ring. Therefore, it is difficult to say that these processes are
industrially favorable processes for producing 3-
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methyltetrahydrofuran.
As processes for producing3-hydroxy-3-methyltetrahydrofuran,
the following processes are known: (e) a process of reacting 2-
hydroxyethyl-2-methyloxirane with tributyltin methoxide and then
thermally decomposing the resultant tin compound to obtain the target
compound [ see Tetrahedron, 38 , pp. 2139-2146 ( 1982 ) ] , ( f ) a process
of decomposing (3-tetrahydrofurylmethanol on an alumina catalyst
[see Bull. Soc. Chim. Fr. , 5-6, Pt 2, pp. 261-266 ( 1980) ] , (g) aprocess
of reacting 4-chloro-3-methyl-1,3-butanediol with KCN [see Nippon
Kagaku Kaishi, pp. 1021-1025 (1977)], (h) a process of decomposing
4,4-dimethyl-1,3-dioxane [see Meiji Daigaku Kagaku Gijutu Kenkyusho
Nempo, 17, p. 22 (1975)].
However, all of the above-mentioned processes have problems.
In the process (e), an expensive compound must be used to produce
3-hydroxy-3-methyltetrahydrofuran, and selectivity of 3-hydroxy-
3-methyltetrahydrofuran is as low as 50~. In the process (f), the
raw material cannot be easily available, and a high temperature of
300~C or higher is necessary for the decomposition. In the process
(g), the main reaction thereof is cyanization and thus 3-
hydroxy-3-methyltetrahydrofuran can be obtained only asa by-product.
In the process (h), 3-hydroxy-3-methyltetrahydrofuran can be
obtained in only a little amount by a by-product, and cannot be
selectively obtained.
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For such reasons, any industrially-established process f or
producing 3-hydroxy-3-methyltetrahydrofuran hasnot been known until
now.
As processes for producing 3-methyldihydrofuran, in
particular, 3-methyl-4,5-dihydrofuran or3-methyl-2,5-dihydrofuran,
the following processes are known: (i) a process of hydroformylating
methacrolein diethylacetal, reducing its aldehyde group, cyclizing
the resultant alcohol compound, and subjecting eliminating ethanol
from the cyclic compound to obtain 3-methyl-4,5-dihydrofuran [see
J. Org_ Chem., 37, p. 1835 (1972)], (j) a process of isomerizing
3-methyl-3,4-epoxy-1-butene in the presence of a higher tertiary
amine and a zinc oxide catalyst to obtain 3-methyl-2, 5-dihydrofuran
[see W091/13882], (k) a process of isomerizing isoprene oxide in the
presence of iron acetylacetonate ( Fe ( acac ) 3 ) and hydrogen iodide to
obtain 3-methyl-2,5-dihydrofuran [see USP 3,932,468], (1) a process
of reacting hydroxyacetone with vinyltriphenylphosphonium bromide,
and following to cyclization reaction of the resultant to obtain
3-methyl-2,5-dihydrofuran [see J. Org. Chem., 33, p. 583 (1968)].
However, in the process (i) , methacrolein, which is not stable,
must be converted to the acetal, a rhodium catalyst using in the
hydroformylation reaction is very expensive, and it needs the number
of steps. In the process (j), the preparation of the catalyst is
difficult. In the process (k) , it is necessary to use hydrogen iodide
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which is highly corrosive. In the process (1), a large amount
of expensive triphenylphosphine is necessary to prepare
vinyltriphenylphosphonium bromide, which is used in a mole
equivalent to hydroxyacetone. Therefore, it is difficult to say
that these processes are industrially-profitable processes for
producing 3-methyldihydrofuran.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a process
for producing 3-methyltetrahydrofuran with simplicity and
industrial-profitability and in a high yield, from a raw
material that can easily be obtained.
Another object of the present invention is to provide a
process for producing 3-hydraxy-3-methyltetrahydrofuran safely,
economically and industrially.
A further object of the present invention is to provide a
process for producing 3-methyldihydrofuran with simplicity and
industrial-profitability and in a high yield.
The present invention is directed to a process for
producing 3-methyltetrahydrofuran, comprising cyclizing 3-
methyl-3-buten-1-of in the presence of iodine.
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The parent application is directed, in a first aspect, to a
process for producing 3-methyltetrahydrofuran, comprising the
steps of reacting 3-methyl-3-~buten-1-of with hydrogen peroxide
in the presence of zeolite tc> obtain 3-hydroxy-3-
methyltetrahydrofuran, and reacting the resultant 3-hydroxy-3-
methyltetrahydrofuran with hydrogen in the presence of an acidic
substance and a hydrogenation catalyst.
In a second aspect, to a process for producing 3-
methyltetrahydrofuran, comprising reacting 3-hydroxy-3-
methyltetrahydrofuran with hydrogen in the presence of an acidic
substance and a hydrogenation catalyst.
In a third aspect, to a process for producing 3-hydroxy-3-
methyltetrahydrofuran, comprising reacting 3-methyl-3-buten-1-of
with hydrogen peroxide in the presence of zeolite.
In a fourth aspect, to a process for producing 3-
methyldihydrofuran, comprising dehydrating 3-hydroxy-3-
methyltetrahydrofuran in the presence of an acidic substance.
In a fifth aspect, to a process for producing 3-
methyltetrahydrofuran, comprising reacting 3-methyldihydrofuran
with hydrogen in the presence of a hydrogenation catalyst.
The present invention is directed to a process for
producing 3-methyltetrahydrofuran, comprising cyclizing 3-
methyl-3-buten-1-of in the presence of iodine.
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DETAILED DESCRIPTION OF THE INVENTION
Each step of the producing process of the present invention
and that of the parent application will be described in detail.
(1) Step of reacting 3-methyl-3-buten-1-of with hydrogen
peroxide in the presence of zeolite to obtain 3-hydroxy-3-
msthyltetrahydrofuran
3-methyl-3-buten-1-ol, which is used as a raw material
in the present step, can easily be synthesized, for example, by
condensing formaldehyde with isobutene under a heating condition
[see Angew. Chem. Int. Ed. Engl., $, p. 556(1969)].
Zeolite acts as a catalyst for the reaction in the
present step. Zeolite includes a metallosilicate such as
titanosilicate prepared from a tetraalkylorthosilicate, a
tetraalkylorthotitanate and a tetraalkylammonium salt as a mold
release agent; and zirconosilicate prepared from a
tetraalkylorthosilicate, a tetraalkylorthozirconate and a
tetraalkylammonium salt as a mold release agent. Among them,
titanosilicate is preferred. More preferred' is TS-
1[titanosilicate obtained by hydrothermal synthesis of a
mixture of tetraethylorothosilicate (Si(OEt)9) and
tetraethylorthotitanate(Ti(OEt)4) (Si(OEt)4 . Ti (OEt)4 - 40
1(molar ratio) at 175°C in the presence of a catalytic amount of
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tetrapropylammonium hydroxide (Pr4NOH)]. The amount of zeolite to
be used is preferably from 0.01 to 100, and more preferably, from
0.1 to 10~ by weight of 3-methyl-3-buten-1-ol. If the amount of
zeolite to be used is less than 0 . O1~ by weight , the reaction trends
to advance slowly. If the amount of zeolite to be used is more than
100 by weight, it is not preferred for easy operation and economy.
The concentration of the hydrogen peroxide to be used is not
especially limited. If the concentration is high, volume efficiency
is improved so that productivity is improved, however, safety
decreases. Considering easy operation, safety,economy andthe like,
it is preferred to use a hydrogen peroxide solution having a
concentration of 10-60~, which is commercially available in general.
The amount of hydrogen peroxide to be used is , the amount converted
to the contained hydrogen peroxide, preferably at a ratio of from
0.5 to 2 moles based on one mole of 3-methyl-3-buten-1-ol.
The reaction can be performed in the presence or absence of
a solvent. The solvent that can be used is not especially limited
unless the solvent has a influence to the reaction. The solvent may
be a solvent that can not be reacted with hydrogen peroxide, examples
of which include halogenated hydrocarbons such as dichloromethane,
1,2-dichloroethane, chloroform, carbon tetrachloride and
chlorobenzene: aliphatic hydrocarbons such as pentane, hexane,
heptane, octane, cyclohexane and cyclooctane; and aromatic
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hydrocarbons such as benzene, toluene, xylene and mesitylene. In
the case of using the solvent, the weight of the solvent to be used
is not especially limited. In general, the weight of the solvent
to be used is preferably from 0.01 to 100 parts by weight, and more
preferably, from 0.1 to 10 parts by weight based on the one part by
weight of 3-methyl-3-buten-l.-of from the viewpoint of smooth advance
of the reaction, easy operation and volume efficiency.
The reaction temperature is preferably within a range from
40 to 100~C. If the reaction temperature is lower than 40~, the
reaction trends to advance very slowly. On the other hand, if the
reaction temperature is higher than 100 , hydrogen peroxide is very
fast decomposed so that control of the reaction trends to be difficult.
The reaction may be performed under the atmosphere, but is
preferably performed under an inert gas such as nitrogen or argon
from the viewpoint of safety. Pressure upon the reaction is not
especiallylimited. The reaction may be performed under atomospheric
pressure, increased pressure or reduced pressure.
The reaction is preferably performed as follows: for example,
3-methyl-3-buten-1-ol, zeol.ite and the optional solvent are mixed
in the atmosphere of an inert gas such as nitrogen or argon and the
temperature of the mixture is set to a given temperature, and
subsequently hydrogen peroxide, preferably in an aqueous solution
form, is added dropwise to this mixture with stirring.
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The thus obtained 3-hydroxy-3-methyltetrahydrofuran can be
isolated and purified in the usual manner for isolation and
purification of organic compounds . For example, the reaction mixture
is f iltrated to remove zeol.ite and subsequently distilled.
(2) Step of reacting3-hydroxy-3-methyltetrahydrofuran with hydrogen
in the presence of an acidic substance and a hydrogenation catalyst
to obtain 3-methyltetrahydrofuran
The acidic substance to be used in the present step contributes
to dehydration reaction of 3-hydroxy-3-methyltetrahydrofuran.
Examples of the acidic substances include inorganic acids or
salts thereof such as hydrochloric acid, sulfuric acid, phosphoric
acid, polyphosphoric acid, sodium hydrogensulfate, potassium
hydrogensulfate, sodium dihydrogenphosphate, potassium
dihydrogenphosphate, sodium hydrogensulfite and potassium
hydrogensulfite; sulfonic acids such as methanesulfonic acid,
benzenesulfonic acid and toluenesulfonic acid; carboxylic acids such
as acetic acid, propionic acid, benzoic acid and terephthalic acid;
heteropolyacids such as phosphotungstic acid, phosphomolybdic acid,
silicotungstic acid and silicomolybdic acid; solid acids such as
silica, alumina,silica-alumina,titania,silica-titania and niobium
oxide; and acidic ion-exchange resins such as sulfonic acid based
ion-exchange resin and carboxylic acid based ion-exchange resin.
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These acidic substances may be used alone, or as a mixture of two
or more of them. Any homogeneous acid such as the above-mentioned
inorganic acid, salt thereof, sulfonic acid, carboxylic acid and
heteropolyacid may be caused to be adsorbed on activated carbon,
silica, alumina, zirconia, titania or the like, so that the resultant
may be used in the same way as the solid acid. The amount of the
acidic substance to be used :is not especially limited. In the case
of using the homogeneous acid such as the above-mentioned inorganic
acid, salt thereof , sulfonic acid, carboxylic acid or heteropolyacid
as the acidic substance, in general, the amount to be used thereof
is preferably from 0.001 to 50~ by mole, and more preferably, from
0.01 to 10$ by mole per mole of 3-hydroxy-3-methyltetrahydrofuran
from the viewpoint of reaction efficiency and economy. In the case
of using the above-mentioned solid acid, the acidic ion-exchange
resin, or the homogeneous acid adsorbed on a carrier as the acidic
substance, in general, the amount to be used thereof is preferably
from 0.01 to 10~ by weight of 3-hydroxy-3-methyltetrahydrofuran.
Examples of the hydrogenation catalyst include noble metal
oxides such as palladium oxide and platinum oxide; noble metal
catalystssuch aspalladium,ruthenium, rhodium or platinumsupported
on a carrier such as activated carbon, silica, silica-alumina,
silica-titania or an acidic ion-exchange resin; nickelcatalystssuch
as nickel oxide, Raney nickel and nickel diatom earth; and copper
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catalysts such as Raney copper, copper chromite and copper zinc.
These hydrogenation catalysts may be used alone, or as a mixture of
two or more of them. The amount of the hydrogenation catalyst to
be used is not especially limited. Usually, the amount of the
hydrogenation catalyst to be used is preferably from 0.001 to 100,
more preferably from 0.01 to 50~, and most preferably from 0.05 to
10~ by weight of 3-hydroxy-3-methyltetrahydrofuran from the
viewpoint of easy operation, reactivity and economy.
In the case of using th.e noble catalyst supported on the acidic
substance such as alumina, silica, silica-alumina, silica-titania
or acidic ion-exchange resin as the hydrogenation catalyst, the
above-mentioned acidic substance may not be used.
The hydrogen pressure isnotespecially limited. Usually, the
hydrogen pressure is preferably from an atomospheric pressure to 20
MPa, more preferably from an atomospheric pressure to 5 MPa, and most
preferably from an atomospheric pressure to 2 MPa from the viewpoint
of easy operation, safety and smooth advance of the reaction.
The reaction can be performed in the presence or absence of
a solvent. The solvent that can be used is not especially limited
unless it has a influence to the reaction. Examples thereof include
aliphatic hydrocarbons such as pentane, hexane, heptane, octane,
nonane, decane, cyclohexane and cyclooctane; aromatic hydrocarbons
such as benzene, toluene, xylene, mesitylene; alcohols such as
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methanol, ethanol, propanol, isopropanol, butanol and octanol; and
ethers such as diethyl ether, diisopropyl ether and tetrahydrofuran.
In the case of using the solvent, the weight of the solvent to be
used is not especially limited. In general, the weight of the
solvent to be used is preferably from 0.01 to 100 parts by weight,
and more preferably, from 0.1 to 10 parts by weight based on the one
part by weight of 3-hydroxy-3-methyltetrahydrofuran from the
viewpoint of smooth advance of the reaction, easy operation and
volume efficiency.
The reaction temperature is preferably within a range from 0
to 200°C, more preferably wii~hin a range from 20 to 150°C, and
most
preferably within a range from 60 to 150°C from the viewpoint of
easy operation, smooth advance of the reaction and safety.
The reaction is preferably performed as follows: for example,
into a reaction vessel are charged 3-hydroxy-3-
methyltetrahydrofuran, the acidic substance, the hydrogenation
catalyst, and the optional solvent, and then the vessel is sealed.
Thereafter, the vessel is pressurized with hydrogen, and the
mixture is stirred at a given temperature. The reaction may be
performed in a batch manner or in a continuous manner.
The thus obtained 3-methyltetrahydrofuran can be isolated
and purified in the usual manner for isolation and
purification of organic compounds. For example, the
reaction mixture is filtrated, the resultant filtrate is
optionally washed with water, and subsequently
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distilled.
(3) Step of subjecting 3-hydroxy-3-methyltetrahydrofuran to
dehydration reaction in the presence of an acidic substance to obtain
3-methyldihydrofuran
Examples of the acidic substances to be used include inorganic
acids or salts thereof such as hydrochloric acid, sulfuric acid,
phosphoric acid, polyphosphoric acid, sodium hydrogensulfate,
potassium hydrogensulfate, sodium dihydrogenphosphate, potassium
dihydrogenphosphate, sodium hydrogensulfite and potassium
hydrogensulfite; sulfonic acids such as methanesulfonic acid,
benezenesulfonic acid and toluenesulfonic acid; carboxylic acids
such as acetic acid, propionic acid, benzoic acid and terephthalic
acid; heteropolyacids such as phosphotungstic acid, phosphomolybdic
acid, silicotungstic acid and silicomolybdic acid; solid acids such
as silica, alumina, silica-alumina, titania, silica-titania and
niobium oxide; and acidic ion-exchange resins such as sulfonic acid
based ion-exchange resin and carboxylic acid based ion-exchange
resin.
These acidic substances may be used alone, or as a mixture
of two or more of them. Any homogeneous acid such as the above-
mentioned inorganic acid, salt thereof, sulfonic acid, carboxylic
acid and heteropolyacid may be caused to be adsorbed on activated
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carbon, silica, alumina, zirconia, titania or the like, so that the
resultant may be used in the same way as the solid acid. The amount
of the acidic substance to tie used is not especially limited. In
the case of using the homogeneous acid such as the above-mentioned
inorganic acid, salt thereof, sulfonic acid, carboxylic acid or
heteropolyacid as the acidic substance, in general, the amount to
be used thereof is preferably from 0.001 to 50~ by mole, and more
preferably, from 0.01 to 10~ by mole per mole of 3-hydroxy-3-
methyltetrahydrofuran from the viewpoint of reaction efficiency and
economy. In the case of using the above-mentioned solid acid, the
acidic ion-exchange resin, or homogeneous acid adsorbed on activated
carbon, silica, alumina or the like as the acidic substance, in general,
the amount to be used thereof is preferably from 0. O1 to 10~ by weight
of 3-hydroxy-3-methyltetrahydrofuran.
The reaction can be performed in the presence or absence. of
a solvent. The solvent that can be used is not especially limited
unless it has a inf luence to the reaction . Examples thereof include
aliphatic hydrocarbons such as pentane, hexane, heptane, octane,
nonane, decane, cyclohexane and cyclooctane; aromatic hydrocarbons
such as benzene, toluene, xylene, mesitylene; alcohols such as
methanol, ethanol, propanol, isopropanol, butanol and octanol; and
ethers such as diethyl ether, diisopropyl ether and tetrahydrofuran
and halogenated hydrocarbons such as dichloromethane, chloroform,
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carbon tetrachloride, 1,2-dichloroethane and chlorobenzene. In the
case of using the solvent, the weight of the solvent to be used is
not especially limited. In general, the weight of the solvent to
be used is preferably from 0.01 to 10 parts by weight, and more
preferably from 0.1 to 2 parts by weight based on the one part by
weight of 3-hydroxy-3-methyltetrahydrofuran from the viewpoint of
smooth advance of the reaction, volume efficiency and economy.
The reaction temperature is preferably within a range from
40 to 200 , and more preferably within a range from 60-140 . If
the reaction temperature is lower than 40~C , the reaction trends to
advance slowly. If the reaction temperature is higher than 200~C,
selectivity of 3-methyldihydrofuran tends to decrease because of
increasing by-products having high-boiling point derived from 3-
methyldihydrofuran.
The reaction can be performed as follows: for example, the
acidic substance, 3-hydroxy-3-methyltetrahydrofuran and the
optional solvent are mixed and stirred at a given temperature. The
reaction may be performed in a batch manner or in a continuous manner.
From the viewpoint of stability of a product and productivity, a
continuous manner is preferred. In the case that the reaction is
performed in a continuous manner, since 3-methyldihydrofuran as the
product has a boiling point lower than 3-hydroxy-3-
methyltetrahydrofuran as a raw material, it is preferred as a reaction
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method that 3-hydroxy-3-methyltetrahydrofuran is added continuously
to the dissolved or suspended solution of the solvent and the acidic
substance, which is kept at a given temperature, while stirring, and
the resultant product is distilled out simultaneously. In this
method, it is preferred to use a solvent having a boiling point higher
than 3-hydroxy-3-methyltetrahydrofuran.
The purity of the resultant 3-methyldihydrofuran, that is,
3-methyl-4,5-dihydrofuran or 3-methyl-2,5-dihydrofuran, can be made
higher by an usual purifying method such as distillation.
(4) Step of reacting 3-methyldihydrofuran with hydrogen in the
presence of a hydrogenation catalyst to obtain 3-
methyltetrahydrofuran
3-methyldihydrofuran that can be used may be, for example,
3-methyl-4,5-dihydrofuran or 3-methyl-2,5-dihydrofuran, or a
mixture thereof.
Examples of the hydrogenation catalyst include noble metal
oxides such as palladium oxide and platinum oxide; noble metal
catalysts such as palladium, ruthenium, rhodium or platinum supported
on carriersuch as activated carbon, silica,alumina,silica-alumina,
silica-titania or an acidic ion-exchange resin; nickel catalystssuch
as nickel oxide, Raney nickel and nickel diatom earth; and copper
catalysts such as Raney copper, copper chromite and copper zinc.
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These hydrogenation catalysts may be used alone, or as a mixture of
two or more of them. The amount of the hydrogenation catalyst to
be used is not especially limited. Usually, the amount of the
hydrogenation catalyst to be used is preferably from 0.001 to 100,
more preferably from 0.01 to 50~, and most preferably from 0.05 to
10~ by weight of 3-methyldihydrofuran from the viewpoint of easy
operation, reactivity and economy.
The hydrogen pressure:is not especially limited. Usually, the
hydrogen pressure is preferably from an atomospheric pressure to 20
MPa, more preferably from an atomospheric pressure to 5 MPa, and most
preferably from an atomospher_ic pressure to 2 MPa from the viewpoint
of easy operation, safety and smooth advance of the reaction.
The reaction can be performed in the presence or absence of
a solvent. The solvent that can be used is not especially limited
unless it has a influence to the reaction. Examples thereof include
aliphatic hydrocarbons such as pentane, hexane, heptane, octane,
nonane, decane, cyclohexane and cyclooctane; aromatic hydrocarbons
such as benzene, toluene, xylene, mesitylene; alcohols such as
methanol, ethanol, propanol, isopropanol, butanol and octanol; and
ethers such as diethyl ether, diisopropyl ether and tetrahydrofuran.
In the case of using the so1_vent, the weight of the solvent to be
used is not especially limited . In general , the weight of the solvent
to be used is preferably frorn 0.01 to 100 parts by weight, and more
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preferably, from 0.1 to 10 parts by weight based on the one part by
weight of 3-methyldihydrofuran from the viewpoint of smooth advance
of the reaction, easy operation and volume efficiency.
The reaction temperature is preferably within a range from
0 to 200, more preferably within a range from 20-150 and most
preferably within a range from 60-150 from the viewpoint of easy
operation, safety, smooth advance of the reaction.
The reaction can be preferably performed as follows: for
example, into a reaction vessel are charged 3-methyldihydrofuran,
the hydrogenation catalyst and the optional solvent, and then the
vessel is sealed. Thereafter, the reaction vessel is pressurized
with hydrogen, and the reactant is stirred at a given temperature.
The reaction may be performed in a batch manner or in a continuous
manner.
The thus obtained 3-methyltetrahydrofuran can be isolated and
purified in the usual manner for isolation and purification of organic
compounds. For example, the reaction mixture is filtrated, the
resultantfiltrate is optionally washed with water, and subsequently
distilled.
( 5 ) Step of cyclizing 3-methyl-3-buten-1-of in the presence of iodine
to obtain 3-methyltetrahydrofuran
Commercially available iodine may be used, but purified iodine,
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for example, purified by sublimation, is preferred. The amount of
iodine to be used is not especially limited. The amount of iodine
to be used is preferably at a ratio of from 0.001 to 1 mole, and more
preferably, at a ratio of from 0.001 to 0.1 mole based on one mole
of 3-methyl-3-buten-1-of from the viewpoint of post-treatment.
The reaction is preferably performed in the presence of a
solvent. The solvent that can be used is not especially limited
unless the solvent has a influence to the reaction. Examples of the
solvent include halogenated hydrocarbons such as dichloromethane,
chloroform, l,2-dichloroethane and carbontetrachloride; etherssuch
as diethyl ether, diisopropyl.ether, dibutyl ether, tetrahydrofuran,
tetrahydropyran, 4-methyltetrahydropyran and 1,4-dioxane;
hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane
and cyclooctane; and alcohols such as methanol, ethanol, propanol,
isopropanol, butanol and tert-butanol. The weight of the solvent
to be used is not especially limited. In general, the weight of the
solvent to be used is preferably 0.01-100 parts by weight, and more
preferably, 0.1-10 parts by weight based on the one part by weight
of 3-methyl-3-buten-1-ol.
The reaction may be preferably performed under an inert gas
atomosphere. Examples of such an inert gas include helium, nitrogen
and argon. These inert gases may be used alone or as a mixture of
two or more of them.
CA 02432664 2003-06-19
The reaction pressure isnot especially limited. The reaction
may be performed under atomospheric pressure, increased pressure or
reduced pressure. Preferably, the reaction may be performed under
atomospheric pressure from t:he viewpoint of reaction devices,
facilities and easy operation.
The reaction temperature is not especially limited. Usually,
the reaction temperature is preferably within a range from -80 to
200 , and more preferably, within a range from 0 to 100 from the
viewpoint of easy operation and safety. If the reaction temperature
is lower than -80~ , the reaction trends to advance very slowly. If
the reaction temperature is higher than 200~C, the amount of by-
products such as isoprene trends to increase.
The reaction is preferably performed as follows : iodine and
the solvent are mixed and the temperature of the mixture is set to
a given temperature. Then, 3-methyl-3-buten-of is added dropwise
to this solution with stirring.
The thus obtained 3-methyltetrahydrofuran can be isolated and
purified in the usual manner for isolation and purification of organic
compounds . For example, sodium thiosulfate is added to the reaction
solution to remove iodine, the solvent is removed if necessary, and
subsequently distillation is performed. Since water is not produced
by a by-product in the present step (5), 3-methyltetrahydrofuran
having a high purity can be obtained by only distillation.
21
CA 02432664 2003-06-19
According to the process of the present invention, it is
possible to produce :3-hydroxy-3-methyltetrahydrofuran, 3-
methyldihydrofuran and 3-rnethyltetrahydrofuran with ease and
industrial profitability and in a high yield from 3-methyl-3-buten-
1-0l as a raw material, which is easily available.
EXAMPLES
The present invention will be in more detail described by way
of Examples hereinafter. The present invention is not however
limited to these Examples.
Example 1
Into a 100 ml three-necked flask equipped with a mechanical
stirrer, a reflux condenser, a thermometer and a dropping funnel
were charged 30 g (0.35 mol) of 3-methyl-3-buten-1-of and 0.3 g of
TS-1 as a catalyst, and then the system was replaced by nitrogen.
The temperature of the mixture was raised to 60°C while stirring
the mixture so that the TS-1 would be homogeneously dispersed.
Thereafter, 40 g (0.35 mol) of aqueous 30% hydrogen peroxide was added
dropwise thereto over 2 hours. After the addition, the reaction
solution was stirred at the same temperature, and advance of
the reaction was traced by gas chromatography analysis (column:
CBP-10, column length: 50 m (G:L Sciences, Inc), column temperature:
70°C
22
CA 02432664 2003-06-19
( constant ) ) . After 2 hours, disappearance of hydrogen peroxide was
confirmed by using paper for detecting hydrogen peroxide. TS-1 was
separated by filtration. To the filtrate was added 0.1 g of cobalt
acetate , and then the mixture was distilled to give 35 . 1 g of a product .
The product contained 32.0 g of 3-hydroxy-3-methyltetrahydrofuran
(conversion of 3-methyl-3-buten-1-ol: 97.3, selectivity of 3-
hydroxy-3-methyltetrahydrofuran: 92.2$).
Example 2
In Example 1, any solvent was not used. The same manner as
in Example 1 was performed except that 30 g of 1,2-dichloroethane
was added as a solvent and further the reaction solution was stirred
with a magnetic stirrer using a stirring tip instead of the mechanical
stirrer, so as to give 33.7 g of a product. The product contained
31.5 g of 3-hydroxy-3-methyltetrahydrofuran (conversion of 3-
methyl-3-buten-1-ol: 95.1, selectivity of 3-hydroxy-3-
methyltetrahydrofuran: 93.10 .
Example 3
The same manner as in Example 2 was performed except that 30
g of toluene was used instead of 30 g of 1,2-dichloroethane, so as
to give 31.3 g of a product. The product contained 29.0 g of 3-
hydroxy-3-methyltetrahydrofuran (conversion of 3-methyl-3-buten-
1-0l: 91.10, selectivity of 3-hydroxy-3-methyltetrahydrofuran:
89 . 40 .
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CA 02432664 2003-06-19
Example 4
Into a 100 ml autoclave (Hastelloy C) equipped with an
electromagnetic stirring device, a pressure gauge, a needle valve,
a gas introducing opening and a sampling opening were charged 20 g
of 3-hydroxy-3-methyltetrahydrofuran, 0.05 g of p-toluenesulfonic
acid, 20 g of toluene and 0.2 g of 5~ palladium-carbon (E106NN, Degussa
AG) , and then the autoclave was sealed. The air inside the autoclave
was replaced by nitrogen, and then the nitrogen was replaced by
hydrogen. Next, the pressure inside the autoclave was increased to
0.5 MPa by hydrogen. The temperature in the system was raised to
100 , and the reaction was performed with stirring for 5 hours. The
pressure inside the reactor was kept at 0. 5 MPa by supplying hydrogen
as consumed in the reaction. After the reaction, the mixture was
cooled to room temperature, and then the inside of the system was
replaced by nitrogen . The mixture was taken out , a portion of this
mixture was analyzed by gas chromatography(column: PEG-HT, column
length: 3 m, column diameter: 4 mm; analysis conditions:: injection
temperature: 220, detector temperature: 240'G, column temperature:
70'C (constant), and carrier gas: helium 40 ml/min., HZ 50 kPa, and
air 50 kPa) to find that conversion of 3-hydroxy-3-
methyltetrahydrofuran was 98.5 ~ and selectivity of 3-
methyltetrahydrofuran was 98~. The resultant reaction solution was
distilled under atomospheric pressure to obtain 17.1 g of 3-
24
CA 02432664 2003-06-19
methyltetrahydrofuran (purity: 98.9%).
Example 5
The same procedures as in Example 4 were performed except that
0.25 g of p-toluenesulfonic acid was used instead of 0.05 g
thereof, 0.1 g of Raney nickel (BK111/w, Degussa AG) was used
instead of 0.2 g of 5% palladium-carbon, and reaction temperature
was set to 120°C. The resultant reaction mixture was analyzed by
gas chromatography under the same analysis conditions as in Example
4 to find that conversion of 3-hydroxy-3-methyltetrahydrofuran was
98%, and selectivity of 3-methyltetrahydrofuran was 97.5%.
Example 6
The same procedures as in Example 4 were performed except that
0.25 g of p-toluenesulfonic acid was used instead of 0.05 g
thereof, 0.5 g of 1% palladium on acidic ion-exchange resin (N. E.
Chemcat Corp.) was used instead of 0.2 g of 5% palladium-carbon,
reaction temperature was set. to 80°C, and reaction time was set to
12 hours. The resultant reaction mixture was analyzed by gas
chromatography under the same analysis conditions as in Example 4
to find that conversion of 3-hydroxy-3-methyltetrahydrofuran was
96%, and selectivity of 3-methyltetrahydrofuran was 95.5%.
Example 7
Into a 200 ml three-necked flask equipped with a thermometer,
a reflux condenser and a magnetic stirrer were charged 50 g (0.48
CA 02432664 2003-06-19
mol) of 3-hydroxy-3-methyltetrahydrofuran, 50 g of mesitylene and
TM
' 0.1 g of acidic ion-exchange resin (AMBERLYST, Organo Corp.). The
temperature of the mixture was raised to 120°C, and the mixture was
stirred for 3 hours while the resultant product having a low
boiling point was distilled out. The amount of the distillate was
54.2 g. The distillate was analyzed by gas chromatography (column:
G-300, 50 m (Chemicals In;~pection & Testing Institute, Japan),
analysis conditions: injection temperature: 240°C, detector
temperature: 220°C, column temperature: 70°C (constant), and
carrier
gas: helium 40 ml/min., H2 50 kPa, and air 50 kPa) to find that
38.3 g of 3-methyldihydrofurans were contained in the distillate
(yield: 95.0%, 3-methyl-2, 5-dihydrofuran: 3-methyl-4, 5-
dihydrofuran = 89 . 11).
Example 8
Into a 100 ml three-necked flask equipped with a thermometer,
a reflux condenser and a magnetic stirrer were charged 20 g
(0.19 mol) of 3-hydroxy-3-methyltetrahydrofuran, 20 g of
mssitylene and 0.01 g of potassium hydrogensulfate. The
temperature of the mixture was raised to 120°C, and the mixture
was stirred for 4.2 hours while the resultant product having a
low boiling point was distilled out. The amount of the
distillate was 22.1 g. The distillate was analyzed by
gas chromatography under the same conditions as in Example 7 to
find that 15.0 g of 3-methyldihydrofurans were contained in the
distillate (yield: 92.8%, 3-methyl-2, 5-dihydrofuran . 3-methyl-4,
26
CA 02432664 2003-06-19
5-dihydrofuran = 90 . 10).
Example 9
Into a 100 ml three-necked flask equipped with a thermometer,
a ref lux condenser and a magnetic stirrer were charged 20 g ( 0 .19
mol) of 3-hydroxy-3-methyltetrahydrofuran, 20 g of decane and 0.01
g of sulfuric acid. The temperature of the mixture was raised to
130°C, and the mixture was stirred for 1.2 hours while the resultant
product having a low boiling point was distilled out. The amount
of the distillate was 24.3 g. The distillate was analyzed by gas
chromatography under the same conditions as in Example 7 to find
that 14.2 g of 3-methyldihydrofurans were contained in the
distillate (yield: 88.8%, 3--methyl-2,5-dihydrofuran . 3-methyl-4,5-
dihydrofuran = 87 . 13).
Example 10
Into a 100 ml autoclave (Hastelloy C) equipped with an
electromagnetic stirring device, a pressure gauge, a needle valve,
a gas introducing opening and a sampling opening were charged 15 g
of 3-methyldihydrofuran (3-methyl-2, 5-dihydrofuran . 3-methyl-4,
5-dihydrofuran - 90 . 10) obtained in Example 8, 15 g of
isopropanol, 0.15 g of 5% palladium-carbon (5%E106NN/W, Degussa
AG), and then the autoclave was sealed. The air inside
the autoclave was replaced by nitrogen, and then the nitrogen
was replaced by hydrogen. Next, the pressure inside the
autoclave was increased to 1 MPa by hydrogen. The temperature in
27
CA 02432664 2003-06-19
the system was raised to 80°C, and the reaction was performed with
stirring for 6 hours. The pressure inside the reactor was kept at
1 MPa by supplying hydrogen as consumed in the reaction. After the
reaction, the mixture was cooled to room temperature, and then the
inside of the system was replaced by nitrogen. The mixture was
taken out, a portion of the mixture was analyzed by gas
chromatography (column: PEG-HT, column length: 3 m, column
diameter: 4 mm; analysis conditions: injection temperature: 220°C,
detector temperature: 240°C, column temperature: 70°C
(constant),
and carrier gas: helium 40 ml/min., H250 kPa, and air 50 kPa) to
find that conversion of 3-methyldihydrofuran was 100% and
selectivity of 3-methyltetrahydrofuran was 97.2%. The mixture was
distilled under atmospheric pressure to obtain 13.2 g of
3-methyltetrahydrofuran (purity: 99.8%).
Example 11
Into a 100 ml three-necked flask equipped with a thermometer,
a dropping funnel and a dimroth condenser were charged 20 ml of
dehydrated dichloromethane and 0.25 g (1 mmol) of iodine, and then
the system was replaced by nitrogen. To this mixture solution was
added dropwise 17.2 g (0.2 mol) of 3-methyl-3-buten-1-of at 27°C
over 1 hour. After the addition, the reaction solution was stirred
at 27°C, and advance of: the reaction was traced by gas
chromatography (column: PEG-HT, column length: 3 m, column diameter:
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CA 02432664 2003-06-19
4 mm, injection temperature: 210 ~C, and column temperature: 70 ~
(constant)). After 8hours, conversion of 3-methyl-3-buten-1-of was
98.2, and selectivity of 3-methyltetrahydrofuran was 96.2$. To this
reaction solution was added 1.4 g of sodium thiosulfate, and then
the mixture was distilled to obtain 14.9 g (recovery ratio: 92~) of
3-methyltetrahydrofuran.
Example 12
Reaction was conducted in the same way as in Example 11 except
that 20 ml of hexane was used instead of 20 ml of dichloromethane.
After 12 hours, conversion of 3-methyl-3-buten-1-of was 89.4, and
selectivity of 3-methyltetrahydrofuran was 89.9.
Example 13
Reaction was conducted in the same way as in Example 11 except
that 20 ml of carbon tetrachloride was used instead of 20 ml of
dichloromethane. After 15 hours, conversion of 3-methyl-3-
buten-1-of was 93. 3~, and selectivity of 3-methyltetrahydrofuran was
92.2$.
Example 14
Reaction was conducted in the same way as in Example 11 except
that the used amount of iodine was changed from 0.25 g (1 mmol) to
2.5 g (10 mmol). After 30 minutes, conversion of 3-methyl-3-
buten-1-of was 99.3, andselectivity of 3-methyltetrahydrofuran was
97.2.
29
