U.S. patent application number 09/772966 was filed with the patent office on 2001-10-11 for process for the isolation of high boilers from the cyclooligomerization of 1,3-butadiene.
This patent application is currently assigned to DEGUSSA-HUELS AKTIENGESELLSCHAFT. Invention is credited to May, Matthias, Oenbrink, Georg, Schiffer, Thomas, WILCZOK, Norbert.
Application Number | 20010029310 09/772966 |
Document ID | / |
Family ID | 7629715 |
Filed Date | 2001-10-11 |
United States Patent
Application |
20010029310 |
Kind Code |
A1 |
Schiffer, Thomas ; et
al. |
October 11, 2001 |
Process for the isolation of high boilers from the
cyclooligomerization of 1,3-butadiene
Abstract
A process for the isolation of high-boiling monomers from
distillation residue formed in the cyclodimerization and/or
cyclotrimerization of 1,3-butadiene after target products of
cyclooctadiene, vinylcyclohexene and/or cyclododecatriene have been
separated off, comprising extracting the distillation residue with
a nonpolar or slightly polar solvent, separating off insoluble
oligomers and polymers that have at least partly crystallized by
mechanical separation, removing the extractant, and isolating the
high-boiling monomers.
Inventors: |
Schiffer, Thomas; (Halten,
DE) ; May, Matthias; (Dorsten, DE) ; WILCZOK,
Norbert; (Mulheim, DE) ; Oenbrink, Georg;
(Dulmen, DE) |
Correspondence
Address: |
OBLON SPIVAK MCCLELLAND MAIER & NEUSTADT PC
FOURTH FLOOR
1755 JEFFERSON DAVIS HIGHWAY
ARLINGTON
VA
22202
US
|
Assignee: |
DEGUSSA-HUELS
AKTIENGESELLSCHAFT
Weissfrauenstrasse 9
D60284 Frankfurt
DE
|
Family ID: |
7629715 |
Appl. No.: |
09/772966 |
Filed: |
January 31, 2001 |
Current U.S.
Class: |
585/809 ;
585/864; 585/866; 585/867 |
Current CPC
Class: |
C07C 7/005 20130101;
C07C 7/10 20130101 |
Class at
Publication: |
585/809 ;
585/864; 585/866; 585/867 |
International
Class: |
C07C 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 3, 2000 |
DE |
10 004 758 |
Claims
1. A process for the isolation of high-boiling monomers from
distillation residue formed in the cyclodimerization and/or
cyclotrimerization of 1,3-butadiene after target products of
cyclooctadiene, vinylcyclohexene and/or cyclododecatriene have been
separated off, comprising extracting the distillation residue with
a nonpolar or slightly polar solvent, separating off insoluble
oligomers and polymers that have at least partly crystallized by
mechanical separation, removing the extractant, and isolating the
high-boiling monomers.
2. The process as claimed in claim 1, wherein the solvent has a
boiling point in the range from 35.degree. C. to 130.degree. C.
3. The process as claimed in claim 2, wherein the solvent has a
boiling point in the range from 50.degree. C. to 105.degree. C.
4. The process as claimed in claim 1, wherein the solvent is
selected from the group consisting of aliphatic, cycloaliphatic,
olefinic and cycloolefinic hydrocarbons, ketones and aldehydes, and
mixtures thereof.
5. The process as claimed in claim 4, wherein the solvent is
acetone.
6. The process as claimed in claim 4, wherein the solvent is
2-butanone.
7. The process as claimed in claim 1, wherein the mechanical
separation comprises sedimentation.
8. The process as claimed in claim 1, wherein the mechanical
separation comprises filtration.
9. The process as claimed in claim 1, wherein further target
product of the cyclodimerization or cyclotrimerization is isolated
from the extract.
10. The process as claimed in claim 1, wherein the high-boiling
monomers isolated comprise C.sub.16 compounds.
11. The process as claimed in claim 5, wherein the mechanical
separation comprises sedimentation.
12. The process as claimed in claim 5, wherein the mechanical
separation comprises filtration.
13. The process as claimed in claim 5, wherein further target
product of the cyclodimerization or cyclotrimerization is isolated
from the extract.
14. The process as claimed in claim 5, wherein the high-boiling
monomers isolated comprise C.sub.16 compounds.
15. The process as claimed in claim 6, wherein the mechanical
separation comprises sedimentation.
16. The process as claimed in claim 6, wherein the mechanical
separation comprises filtration.
17. The process as claimed in claim 6, wherein further target
product of the cyclodimerization or cyclotrimerization is isolated
from the extract.
18. The process as claimed in claim 6, wherein the high-boiling
monomers isolated comprise C.sub.16 compounds.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a process for the isolation of high
boilers, in particular C.sub.16 isomers, which are formed in the
catalytic dimerization and trimerization of 1,3-butadiene.
[0003] 2. Discussion of the Background
[0004] The reaction of 1,3-butadiene is carried out industrially
over transition metal complexes or transition metal complex salts
which are generally present as homogeneous solutions in a nonpolar
organic phase. Suitable solvents are inert hydrocarbons such as
benzene. The catalyst used is typically a transition metal of the
4th to 10th group of the Periodic Table in the oxidation state 0
and, if desired, a ligand such as a phosphine or a phosphite (W.
Brenner, P. Heimbach, H. Hey, E. W. Muller, G. Wilke, Liebigs Ann.
Chem. 727, 1969, 161-182; DE 12 83 836, Studiengesellschaft Kohle;
DE 19 42 729, Mitsubishi Petrochemical Company Ltd.). Depending on
the catalyst system, the main products formed are either the
dimerization products cyclooctadiene (COD) and vinylcyclohexene
(VCH) or the trimerization product cyclododecatriene (CDT). The
selectivity of the reaction over the catalysts is high. It is
generally over 90% in favor of the main component desired in each
case.
[0005] After the reaction, the homogeneous catalyst is first
decomposed and separated off. The decomposition is typically
carried out by means of polar solvents such as monoalcohols having
from 1 to 6 carbon atoms and water or by means of dilute acids. The
reaction mixture (organic phase) is subsequently worked up by
distillation. Here, unreacted 1,3-butadiene and solvent are
returned to the reaction process; the various dimerization and
trimerization products are subsequently separated from one another
by distillation.
[0006] The bottoms from the column consist of a product mixture
comprising oligomers and polymers of 1,3-butadiene as well as
numerous high-boiling monomers having a defined molecular
structure.
[0007] Typical monomers are compounds having from 12 to 30 carbon
atoms, comprising a ring framework of from 6 to 24 carbon atoms and
possibly one or more side chains. Important, nonlimiting
representatives of such monomers are
3-(2-butenyl)-1,5,9-cyclododecatriene,
3-(3-butenyl)-1,5,9-cyclododecatriene and
3-(1-methylpropenyl)-1,5,9-cycl- ododecatriene as well as
cyclohexedeca-1,5,9,13-tetraene.
[0008] Many of these macrocyclic monomers have been able to be
isolated on a laboratory scale and their structure elucidated.
Comprehensive descriptions may be found in DE 19 06 361 (Toyo Rayon
Co.), GB 1 287 252 (Toray Industries), and in DE 20 63 348, US 3
658 926 and JP 48 019 304, cited according to CA 79:78229 (all
Mitsubishi Petrochemical Co. Ltd.).
[0009] Difficulties generally occur in the selective synthesis of
defined macrocycles. Studies have been carried out, for example, on
the ring-opening metathesis of 1,5-cyclooctadiene over tungsten (E.
A. Ofstead, Macromol. Synth. 1977, 6, 69), rhodium (K. Saito et
al., Bull. Chem. Soc. Jpn. 1979, 52, 3192) or rhenium catalysts (US
3 865 888) and the oligomerization of 1,3-butadiene in which, if
desired, linear dimers such as 1,3,7-n-octatriene may also be added
(DE 20 63 348). All the methods give a product mixture comprising
not only various macrocycles but also amounts of VCH, COD, CDT and
polybutadienes. Only the selective syntheses of CDT and COD are
used on an industrial scale.
[0010] In the selective synthesis of CDT or COD, a high-boiling,
occasionally yellowish residue remains as bottoms from the
distillation column in the customary form of work-up. At room
temperature, this residue either remains a highly viscous liquid or
solidifies to a wax-like solid, depending on composition.
Distillation does not allow any further useful product to be
isolated from this residue with a justifiable input of energy. The
bottoms from the column are therefore generally incinerated as a
waste product.
[0011] Extraction is a possible method of separating the
high-boiling monomers and polymeric constituents. In GB 1 287 252,
Example 1, this is carried out by addition of large amounts of
acetone (500 g) relative to the reaction mixture (162 g of
butadiene and 20 ml of toluene as solvent). In the other examples
of GB 1 287 252, in which the reaction mixture is worked up and not
only analyzed by gas chromatography, extraction with acetone as
described in Example 1 is also employed.
[0012] In DE 19 06 361, not only toluene but also hexane, benzene,
ether, i.e., diethyl ether, and tetrahydrofuran are mentioned as
solvents. Here too, large amounts of acetone (500 g) relative to
the solvent (in general from about 10 to 50 ml) are used as
extractant. If larger volumes of solvent are used, viz., 200 ml of
toluene (Example 10) or 250 ml of hexane (Example 15), the amount
of solvent is reduced by distillation before acetone is added as
extractant. However, in all cases the dimerization and
trimerization products COD, VCH and CDT remain in the reaction
mixture and are consequently also taken up in the acetone. JP 49
007 153 (cited according to CA 81:13184) also mentions acetone for
the extraction.
[0013] However, application of the above-described extraction
method to the selective synthesis of CDT or COD presents
considerable difficulties. Thus, direct addition of acetone to the
reaction mixture precipitates the polymeric or oligomeric
components only very incompletely, if at all. It has also been
found that the solvents described, in particular the aromatic and
ether compounds, readily dissolve the oligomeric and polymeric
components and thus make the extraction considerably more
difficult.
[0014] Owing to the large amounts of CDT or COD which are also to
be extracted in the selective synthesis of these compounds, the
amount of acetone required for implementation of the prior art on
an industrial scale would be tremendous.
SUMMARY OF THE INVENTION
[0015] It is therefore an object of the invention to provide a
process for the isolation of high-boiling monomers from the
distillation residue formed in the cyclodimerization and
cyclotrimerization of 1,3-butadiene after the target products
cyclooctadiene, vinylcyclohexene and/or cyclododecatriene have been
separated off, which process does not have the abovementioned
disadvantages.
[0016] It has now surprisingly been found that the high-boiling
monomers can be readily extracted from the distillation residue
using particular solvents without relatively large amounts of the
oligomeric and polymeric components being dissolved at the same
time. The insoluble oligomers and polymers can then be separated
off predominantly in pulverulent, crystalline and surprisingly
readily filterable form. With appropriate selection of the
extractant, the extractant can easily be separated from the
extracted monomers, preferably by distillation, and the monomers
obtained in this way can then be isolated in pure form, preferably
by means of vacuum distillation. (As used herein, the term
"solvent" or "solvents" is intended to include solvent
mixtures.)
[0017] The invention accordingly provides a process for the
isolation of high boiling monomers from the distillation residue
formed in the cyclodimerization and/or cyclotrimerization of
1,3-butadiene and separation of the target products, wherein
[0018] the low boilers and solvent are separated off,
[0019] the desired target products such as cyclooctadiene or
cyclododecatriene are isolated by distillation,
[0020] the distillation residue is extracted with a nonpolar or
slightly polar solvent or solvent mixture,
[0021] insoluble oligomers and polymers (partly) crystallize and
are separated off by a mechanical separation operation,
[0022] the extractant is removed, and
[0023] the high-boiling monomers are isolated.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The invention is a process for the isolation of high boiling
monomers from the distillation residue formed in the
cyclodimerization and/or cyclotrimerization of 1,3-butadiene and
separation of the target products, wherein
[0025] the low boilers (e.g. unreacted 1,3-butadiene) and solvent
are separated off,
[0026] the desired target products such as cyclooctadiene or
cyclododecatriene are isolated by distillation,
[0027] the distillation residue is extracted with a nonpolar or
slightly polar solvent or solvent mixture,
[0028] insoluble oligomers and polymers (partly) crystallize and
are separated off by a mechanical separation operation (e.g.
filtration),
[0029] the extractant is preferably removed as low boiler by
distillation and
[0030] the high-boiling monomers are preferably isolated in pure
form by vacuum distillation.
[0031] Studies on the extraction of the distillation residue showed
that the extraction is very strongly dependent on the choice of
solvent. It was surprisingly found that both nonpolar solvents such
as unbranched or branched aliphatic hydrocarbons, preferably having
from 5 to 10 carbon atoms (e.g. pentane, hexane and octane),
cycloaliphatic hydrocarbons having preferably from 5 to 10 carbon
atoms (e.g. cyclohexane), unbranched or branched olefinic and
cycloolefinic hydrocarbons having preferably from 5 to 12 carbon
atoms (e.g. cyclooctene) and also some slightly polar, aprotic
solvents such as branched or unbranched aliphatic and
cycloaliphatic ketones and aldehydes preferably having a total of
from 3 to 12 carbon atoms and their mixtures are very suitable as
extractants. Preferred solvents from the group of ketones are
acetone and 2-butanone (methyl ethyl ketone). Supercritical gases
such as carbon dioxide and ethane are also suitable in principle as
extractants.
[0032] It has surprisingly been found that the aromatics, alcohols
and ethers used in the prior art are, in contrast, less well
suited. In general, the solubility of the monomers in alcohols is
too low. In aromatics and ethers, the oligomers and polymers
dissolve too well.
[0033] In the cyclodimerization or cyclotrimerization of
1,3-butadiene, the process of the present invention provides for
volatile components to be separated off first and the respective
main product to be freed of high-boiling components by being taken
off at the top in the distillation. The bottoms from the column are
then a viscous mixture of high boilers which cannot be distilled
further at justifiable cost. The bottoms are then, according to the
invention, digested with a solvent or solvent mixture
(extractant/extractant mixture), preferably at elevated temperature
under reflux. Here, the heat of the bottoms from the column can be
exploited for heating the extractant. After digestion and cooling,
the insoluble components are separated off by means of a mechanical
separation operation such as a filtration or sedimentation. The
solvent or solvent mixture is preferably separated from the extract
by distillation and can be reused in the extraction process. In
particular cases, a chromatographic separation, e.g., preparative
liquid chromatography (HPLC), can also be carried out. This leaves
a high-boiling oil which is low in oligomers and polymers and can
then be further purified by distillation, preferably under reduced
pressure, or by means of suitable chromatographic separation
processes.
[0034] The solvent or solvent mixture for the extraction is chosen
so that the monomeric substances are largely leached from the
bottoms while a major part of the oligomeric and polymeric
components remains insoluble. Choice of the correct extractant also
makes it possible for the insoluble fraction of the bottoms to
begin to crystallize during digestion. Uniform cooling of the
extraction mixture allows the crystallization to be increased, as a
result of which the proportion of dissolved polymers in the extract
is further reduced.
[0035] The precipitate obtained consists mainly of oligomers and
polymers of 1,3-butadiene. It is generally colorless and at least
partly crystalline. When the correct extractant and the correct
temperature are chosen, it is no longer sticky or only slightly
sticky and can thus easily be separated off, for example by means
of a filter or a suction filter. When cooling the extraction
mixture, a lower temperature limit results from either the
solubility of the monomeric components in the extractant becoming
too low or the monomers freezing out from the mixture. In both
cases, this is clearly indicated by the extraction mixture becoming
milky and the precipitate conglutinating. The precise temperature
limit is, inter alia, in each case dependent on the extractant and
the composition of the high boilers in the bottoms. It is usually
in the range from +15.degree. C. to -10.degree. C.
[0036] The boiling range of the solvents used for the extraction
should be from 35 to 130.degree. C. A particularly preferred
boiling range is from 50 to 105.degree. C. If desired, the
extraction can also be carried out under superatmospheric
pressure.
[0037] In the case of solvents having boiling points above
110.degree. C., the oligomeric and polymeric components melt, which
prevents crystallization of these components during digestion under
reflux. In the case of solvents having boiling points below
35.degree. C., the boiling point of the extractant is too close to
the lower temperature limit for solubility of the high-boiling
monomers. The desired properties of the extractant can also be set
particularly well by combining two or more solvents.
[0038] As a further secondary effect of the process of the
invention, it is found that residual amounts of the main product
which can no longer be isolated by distillation from the bottoms
from the column can be made accessible by extraction. In this way,
further target product (main product) from the cyclodimerization or
cyclotrimerization can be isolated.
[0039] If the high boilers originate, for example, from the bottoms
from the cyclododecatriene column, further cyclododecatriene can be
isolated by means of the extraction.
[0040] Potential application areas for these high-boiling monomers
are in the perfume and fragrance industry, for example, in the
synthesis of macrocyclic ketones (JP 57 021 254, Takasago Perfumery
Co., cited in CA 97:162 457). However, a main application for these
compounds is as crosslinkers in synthetic rubbers.
[0041] Having generally described this invention, a further
understanding can be obtained by reference to certain specific
examples of the inventive process, which are provided herein for
purposes of illustration only and are not intended to be limiting
unless otherwise specified.
EXAMPLES
Examples of Extraction
[0042] In the following examples, a distillation residue from the
preparation of cyclododecatriene was used. This was in each case
taken up in 400 ml of extractant and digested under reflux for 1
hr. The mixture was subsequently cooled to 20.degree. C. or
4.degree. C., allowed to stand overnight and subsequently filtered.
The filtrate was freed of the extractant and filtrate and filter
cake were weighed. The losses between initial and final weights
were caused by adhesion to the laboratory apparatus used. The
results are summarized in Table 1.
Example of Distillation
[0043] 411.1 g of filtrate from Experiment 6 were distilled under
reduced pressure via a 1 m packed column. A further 7.0 g of CDT
isomers (colorless oil, 78-85.degree. C./2 mbar) and also 107.3 g
of a mixed fraction (light-yellow oil, 110-122.degree. C./2 mbar)
and 238.29 g of a C.sub.16 main fraction (colorless oil,
124-126.degree. C./2 mbar) were able to be isolated. The remainder
stayed as a dark residue at the bottom. Analysis of the C.sub.16
fraction indicated 3-(2-butenyl)1,5,9-cyclododecatriene as one of
the main products.
1 Residue weighed Filtration Weight of Weight of Appearance
Appearance of No. Extractant (bp in .degree. C.) in (g) at
(.degree. C.) filtrate (g) precipitate (g) of filtrate precipitate
1 n-Pentane (36) 151.3 4 120.4 22.1 yellow oil 1) colorless,
slightly sticky 2 n-Hexane (68) 161.9 20 147.7 8.34 yellow oil 1)
colorless, pulverulent 3 n-Heptane (98) 155.1 20 128.7 20.5 yellow
oil colorless, slightly sticky 4 Petroleum ether (.about.100) 171.7
20 158.2 9.4 yellow oil 1) colorless, pulverulent 5 Petroleum ether
(.about.100) 148.2 4 83.7 54.2 yellow oil colorless, sticky 6
Acetone (56) 134.1 20 75.6 52.4 yellow oil colorless, sticky 7
2-Butanone (79) 166.4 20 144.9 11.8 yellow oil 1) colorless,
pulverulent 8 2-Butanone (79) 125.6 4 103.9 16.0 yellow oil
colorless, pulverulent 9 3-Pentanone (102) 150.9 4 96.3 40.1 yellow
oil colorless, pulverulent 10 Cyclopentanone (129) 154.3 4 122.3 3)
58.7 yellow oil colorless, slightly sticky 11 Propionaldehyde (48)
150.8 4 53.0 97.2 yellow oil yellow, pulverulent Comparative
examples for less suitable solvents 12 Isopropanol (82) 154.6 20
64.68 84.31 yellow oil colorless, sticky 13 Toluene (110) 163.2 20
-- -- yellow oil - 2) 14 THF 148.3 20 -- -- yellow oil - 2) 1)
Filtrate clear; a fine, colorless precipitate is formed on taking
off the extractant 2) Completely dissolved, therefore no
precipitate can he separated off 3) Still Contains about 10% of
extractant
[0044] The disclosure of German application 100 04 758.0, filed
Feb. 3, 2000, of which priority is claimed under 35 U.S.C. 119, is
hereby incorporated by reference.
* * * * *