U.S. patent application number 17/722794 was filed with the patent office on 2022-08-04 for catalyst composition and process for oligomerization of ethylene.
This patent application is currently assigned to SABIC Global Technologies B.V.. The applicant listed for this patent is SAUDI BASIC INDUSTRIES CORPORATION. Invention is credited to MOHAMMED H. AL-HAZMI, ABDULLAH ALQAHTANI, HEINZ BOELT, MARCO HARFF, ANDREAS MEISWINKEL, BERND H. MUELLER, WOLFGANG MUELLER, NORMEN PEULECKE, UWE ROSENTHAL, ANINA WOEHL.
Application Number | 20220241764 17/722794 |
Document ID | / |
Family ID | 1000006272364 |
Filed Date | 2022-08-04 |
United States Patent
Application |
20220241764 |
Kind Code |
A1 |
WOEHL; ANINA ; et
al. |
August 4, 2022 |
CATALYST COMPOSITION AND PROCESS FOR OLIGOMERIZATION OF
ETHYLENE
Abstract
A catalyst composition including: (a) a chromium compound; (b) a
ligand of the general structure (A)
R.sub.1R.sub.2P--N(R.sub.3)--P(R.sub.4)--NR.sub.5R.sub.6 or (B)
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7)R.sub.8 or
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7).sub.2, with X.dbd.O or S,
wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6,
R.sub.7 and R.sub.8 are independently C.sub.1-C.sub.10-alkyl,
C.sub.6-C.sub.20-aryl, C.sub.3-C.sub.10-cycloalkyl, aralkyl,
alkylaryl, or trialkylsilyl, or any cyclic derivatives of (A) and
(B), wherein at least one of the P or N atoms of the PNPN-unit or
PNP-unit is a member of the ring system, the ring system being
formed from one or more constituent compounds of structures (A) or
(B) by substitution; and (c) an activator or co-catalyst; and a
process for tri- and/or tetramerization.
Inventors: |
WOEHL; ANINA; (Munich,
DE) ; MEISWINKEL; ANDREAS; (Munich, DE) ;
BOELT; HEINZ; (Munich, DE) ; MUELLER; BERND H.;
(Munich, DE) ; MUELLER; WOLFGANG; (Munich, DE)
; PEULECKE; NORMEN; (Munich, DE) ; ROSENTHAL;
UWE; (Munich, DE) ; HARFF; MARCO; (Munich,
DE) ; AL-HAZMI; MOHAMMED H.; (Riyadh, SA) ;
ALQAHTANI; ABDULLAH; (Riyadh, SA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAUDI BASIC INDUSTRIES CORPORATION |
RIYADH |
|
SA |
|
|
Assignee: |
SABIC Global Technologies
B.V.
Bergen op Zoom
NL
|
Family ID: |
1000006272364 |
Appl. No.: |
17/722794 |
Filed: |
April 18, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16355298 |
Mar 15, 2019 |
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17722794 |
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15379836 |
Dec 15, 2016 |
10265690 |
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16355298 |
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14908026 |
Jan 27, 2016 |
9561500 |
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PCT/IB2014/063485 |
Jul 28, 2014 |
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15379836 |
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62008237 |
Jun 5, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01J 2531/62 20130101;
B01J 31/143 20130101; C07C 2531/14 20130101; B01J 2231/20 20130101;
C07C 2/32 20130101; C07C 2531/22 20130101; Y02P 20/52 20151101;
B01J 31/1885 20130101; C07C 2531/24 20130101; C07C 2/36
20130101 |
International
Class: |
B01J 31/18 20060101
B01J031/18; B01J 31/14 20060101 B01J031/14; C07C 2/36 20060101
C07C002/36; C07C 2/32 20060101 C07C002/32 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 29, 2013 |
EP |
13178362.3 |
Claims
1. A catalyst composition comprising: (a) a chromium compound; (b)
a ligand of the general structure (A)
R.sub.1R.sub.2P--N(R.sub.3)--P(R.sub.4)--NR.sub.5R.sub.6 or (B)
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7)R.sub.8 or
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7).sub.2, with X.dbd.O or S,
wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.7 and R.sub.8 are
independently C.sub.1-C.sub.10-alkyl, C.sub.6-C.sub.20-aryl,
C.sub.3-C.sub.10-cycloalkyl, aralkyl, alkylaryl, or trialkylsilyl,
or any cyclic derivatives of (A) and (B), wherein at least one of
the P or N atoms of the PNPN-unit or PNP-unit is a member of the
ring system, the ring system being formed from one or more
constituent compounds of structures (A) or (B) by substitution; and
(c) an activator or co-catalyst; wherein at least one of R.sub.5 or
R.sub.6 is not OEt.
2-11. (canceled)
12. A process for tri- and/or tetramerization of ethylene,
comprising subjecting a catalyst composition to a gas phase of
ethylene in a reactor and conducting an oligomerization; wherein
the catalyst composition comprises (a) a chromium compound; (b) a
ligand of the general structure (A)
R.sub.1R.sub.2P--N(R.sub.3)--P(R.sub.4)--NR.sub.5R.sub.6 or (B)
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7)R.sub.8 or
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7).sub.2, with X.dbd.O or S,
wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6,
R.sub.7 and R.sub.8 are independently C.sub.1-C.sub.10-alkyl,
C.sub.6-C.sub.20-aryl, C.sub.3-C.sub.10-cycloalkyl, aralkyl,
alkylaryl, or trialkylsilyl, or any cyclic derivatives of (A) and
(B), wherein at least one of the P or N atoms of the PNPN-unit or
PNP-unit is a member of the ring system, the ring system being
formed from one or more constituent compounds of structures (A) or
(B) by substitution; (c) and an activator or co-catalyst.
13. A process according to claim 12, wherein the oligomerization is
carried out at a pressure of 1 to 200 bar.
14. A process according to claim 12, wherein the oligomerization is
carried out at a temperature of from 10 to 200.degree. C.
15. A process according to claim 12, wherein the mean residence
time is from 10 minutes to 20 hours.
16. The catalyst composition according to claim 1, wherein the
ligand is Ph.sub.2P--N(i-Pr)--P[S(i-Pr)].sub.2,
Ph.sub.2P--N(i-Pr)P(OCH.sub.3).sub.2, or a combination thereof.
17. The catalyst composition according to claim 1, wherein the
ligand is Ph.sub.2P--N(i-Pr)--P[S(i-Pr)].sub.2.
18. The catalyst composition according to claim 1, wherein the
ligand is Ph.sub.2P--N(i-Pr)P(OCH.sub.3).sub.2.
19. The catalyst composition according to claim 1, wherein the
chromium compound is CrCl.sub.3(THF).
20. A catalyst composition according to claim 1, wherein the
chromium compound is Cr(III)acetylacetonate, Cr(III)octanoate,
chromium hexacarbonyl, Cr(III)-2-ethylhexanoate,
(benzene)tricarbonyl-chromium, or a combination comprising at least
one of the foregoing.
21. A catalyst composition according to claim 1, wherein the
activator or co-catalyst is trimethylaluminum, triethylaluminum,
triisopropylaluminum, triisobutylaluminum,
ethylaluminumsesquichloride, diethylaluminum chloride,
ethylaluminumdichloride, methylaluminoxane (MAO), or a combination
comprising at least one of the foregoing.
22. A catalyst composition according to claim 1, wherein the
activator or co-catalyst is trimethylaluminum.
23. A catalyst composition according to claim 1, wherein the
activator or co-catalyst is triethylaluminum.
24. A catalyst composition according to claim 1, wherein the
activator or co-catalyst is triisopropylaluminum.
25. A catalyst composition according to claim 1, wherein the
activator or co-catalyst is triisobutylaluminum.
26. A catalyst composition according to claim 1, wherein the
activator or co-catalyst is methylaluminoxane (MAO).
27. A method for preparing a catalyst composition, the process
comprising combining (a) a chromium compound; (b) a ligand of the
general structure (A)
R.sub.1R.sub.2P--N(R.sub.3)--P(R.sub.4)--NR.sub.5R.sub.6 or (B)
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7)R.sub.8 or
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7).sub.2, with X.dbd.O or S,
wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6,
R.sub.7 and R.sub.8 are independently C.sub.1-C.sub.10-alkyl,
C.sub.6-C.sub.20-aryl, C.sub.3-C.sub.10-cycloalkyl, aralkyl,
alkylaryl, or trialkylsilyl, or any cyclic derivatives of (A) and
(B), wherein at least one of the P or N atoms of the PNPN-unit or
PNP-unit is a member of the ring system, the ring system being
formed from one or more constituent compounds of structures (A) or
(B) by substitution; (c) and an activator or co-catalyst, to form
the catalyst.
28. A method according to claim 27, wherein the activator or
co-catalyst is triisopropylaluminum.
29. A method according to claim 27, wherein the activator or
co-catalyst is triisobutylaluminum.
30. A method according to claim 27, wherein the activator or
co-catalyst is methylaluminoxane (MAO).
Description
BACKGROUND
[0001] The present invention relates to a catalyst composition and
a process for the oligomerization, especially tri- and
tetramerization, of ethylene.
[0002] Existing processes for the production of linear alpha
olefins (LAOs), including comonomer-grade 1-hexene and 1-octene,
rely on the oligomerization of ethylene. These processes have in
common that they lead to a product distribution of
ethylene-oligomers of chain length 4, 6, 8 and so on. This is due
to a chemical mechanism which is widely governed by competing chain
growth- and displacement reaction steps, leading to a Schulz-Flory-
or Poisson-product distribution.
[0003] From the marketing point of view, this product distribution
poses a formidable challenge for the full-range alpha olefins
producer. The reason is that each market segment served exhibits a
very different behavior in terms of market size and growth,
geography, fragmentation etc. It is, therefore, very difficult for
the producer to adapt to the market requirements since part of the
product spectrum might be in high demand in a given economic
context, while at the same time other product cuts might not be
marketable at all or only in a marginal niche. Currently, the
highest-value LAO product is comonomer-grade 1-hexene for the
polymer industry, while 1-octene demand is also growing at a
considerable rate.
[0004] WO 2009/006979 A2 describes a catalyst composition and a
process for the di-, tri- and/or tetramerization of ethylene. The
catalyst composition comprises a chromium compound, a ligand of,
for example, the general structure
R.sub.1R.sub.2P--N(R.sub.3)--P(R.sub.4)--N(R.sub.5)--H and a
co-catalyst acting as an activator. The ligand's substituents
R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are independently a
number of functional groups, comprising (among others)
C.sub.1-C.sub.10-alkyl, aryl and substituted aryl.
[0005] The chromium source is CrCl.sub.3(THF).sub.3,
Cr(III)acetylacetonate, Cr(III)octanoate, Cr-hexacarbonyl,
Cr(III)-2-ethylhexanoate and (benzene)tricarbonyl-chromium
(THF=tetrahydrofurane).
[0006] The co-catalyst or activator is trimethylaluminum,
triethylaluminum, triisopropylaluminum, triisobutylaluminum,
ethylaluminumsesquichloride, diethylaluminum chloride,
ethylaluminumdichloride, methylaluminoxane or a combination
comprising at least one of the foregoing.
This prior art discloses a class of catalyst systems for selective
ethylene oligomerization reactions.
[0007] For example, one embodiment uses a specific catalyst
composition, chosen from this class of catalyst systems, for the
highly selective trimerization of ethylene to afford high yields of
1-hexene.
[0008] This choice of catalyst constituents comprises
CrCl.sub.3(THF).sub.3 as chromium source, triethylaluminum as
activator, and (Ph).sub.2P--N(i-Pr)--P(Ph)-N(i-Pr)--H as ligand for
the catalytically active complex (Ph=phenyl group, i-Pr=isopropyl
group). This ligand features the typical PNPN--H--backbone, which
is why this class of compounds, regardless of the precise nature of
its substituents, is often referred to as a "PNPN--H--ligand".
[0009] WO 2010/115520 A1 describes essentially modified catalyst
systems of the general type already disclosed in WO2009/006979 A2.
These modified systems take advantage from the same PNPN--H--type
ligands that were already known. However, now a "modifier" is added
to the system, (but not limited to) ammonium or phosphonium salts
of the type [H.sub.4E]X, [H.sub.3ER]X, [H.sub.2ER.sub.2]X,
[HER.sub.3]X or [ER.sub.4]X (with E=N or P, X.dbd.Cl, Br or I and
R=alkyl, cycloalkyl, acyl, aryl, alkenyl, alkynyl etc.).
[0010] Preferred embodiments involve, for instance, modifiers such
as tetraphenylphosphonium chloride, tetraethylammonium
chloride-monohydrate, triethylamine-hydrochloride etc. Also, as a
"type [ER.sub.4]X"--modifier, dodecyl trimethylammonium chloride
can advantageously be used, due to its low price, abundant supply
and good solubility in the reaction solution. By means of the
halogen-containing modifier, the catalyst system allows for an
independent adjustment of the [Cr]/[Halogen] molar ratio in the
resulting catalytically active species which is formed in-situ
under oligomerization conditions.
[0011] On technical scale, the prior art oligomerization
technologies described above are mainly suitable for the production
of 1-butene and 1-hexene for use as co-monomers in the polyethylene
(PE) production, especially for linear low density polyethylene
(LLDPE).
Currently, most of the co-monomer used for PE production is
1-butene followed by an increasing 1-hexene demand. However, some
high-quality PE-materials featuring high tensile strength and crack
resistance require 1-octene as co-monomer. So far, the largest
quantity of 1-octene is obtained from full-range LAO-processes or
extraction from Fischer-Tropsch streams. Since these technologies
are burdened with rather big amounts of other products than
1-octene, their economic viability varies greatly with
technological and economic boundary conditions. This pertains to
infrastructure, market access and price development for the
full-range products under the local boundary conditions.
[0012] It is, therefore, desirable to have catalyst systems and
processes with a higher selectivity towards 1-octene available.
Since 1-hexene is also a valuable co-monomer, combined
1-hexene/1-octene processes are economically interesting as
well.
SUMMARY
[0013] In an embodiment, a catalyst composition comprises:
[0014] (a) a chromium compound;
[0015] (b) a ligand of the general structure
[0016] (A) R.sub.1R.sub.2P--N(R.sub.3)--P(R.sub.4)--NR.sub.5R.sub.6
or
[0017] (B) R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7)R.sub.8 or
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7).sub.2, with X.dbd.O or
S,
wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6,
R.sub.7 and R.sub.8 are independently C.sub.1-C.sub.10-alkyl,
C.sub.6-C.sub.20-aryl, C.sub.3-C.sub.10-cycloalkyl, aralkyl,
alkylaryl, or trialkylsilyl, or any cyclic derivatives of (A) and
(B), wherein at least one of the P or N atoms of the PNPN-unit or
PNP-unit is a member of the ring system, the ring system being
formed from one or more constituent compounds of structures (A) or
(B) by substitution; and
[0018] (c) an activator or co-catalyst.
[0019] In another embodiment, a method of obtaining the catalyst
comprises combining at least (a) a chromium compound; (b) a ligand
of the general structure (A) or (B) as described above; and (c) an
activator or co-catalyst.
[0020] In still another embodiment, a process for tri- and/or
tetramerization of ethylene comprises subjecting the
above-described catalyst composition to a gas phase of ethylene in
a reactor and conducting an oligomerization.
DETAILED DESCRIPTION
[0021] Described herein is a catalyst composition and a process for
oligomerization with a high selectivity towards 1-octene overcoming
the disadvantages of the prior art. Especially a catalyst and
process shall be provided, which allow production of 1-octene in
higher selectivities, while processes having a combined production
of 1-hexene/1-octene are also of interest. The catalyst composition
comprises: (a) a chromium compound; (b) a ligand of the general
structure
[0022] (A) R.sub.1R.sub.2P--N(R.sub.3)--P(R.sub.4)--NR.sub.5R.sub.6
or
[0023] (B) R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7)R.sub.8 or
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7).sub.2, with X.dbd.O or S,
wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6,
R.sub.7 and R.sub.8 are independently C.sub.1-C.sub.10-alkyl,
C.sub.6-C.sub.20-aryl, C.sub.3-C.sub.10-cycloalkyl, aralkyl,
alkylaryl, or trialkylsilyl, or any cyclic derivatives of (A) and
(B), wherein at least one of the P or N atoms of the PNPN-unit or
PNP-unit is a member of the ring system, the ring system being
formed from one or more constituent compounds of structures (A) or
(B) by substitution; and (c) an activator or co-catalyst.
As is to be understood, any cyclic derivatives of (A) and (B) can
be utilized as ligand, wherein at least one of the P or N atoms of
the PNPN-unit (structure (A)) or PNP-unit (structure (B)) is a ring
member, the ring being formed from one or more constituent
compounds of structures (A) or (B) by substitution, i.e. by
formally eliminating per constituent compound either two whole
groups R.sub.1-R.sub.8 (as defined) or H, one atom from each of two
groups R.sub.1-R.sub.8 (as defined) or a whole group
R.sub.1-R.sub.8 (as defined) or H and an atom from another group
R.sub.1-R.sub.8 (as defined), and joining the formally so-created
valence-unsaturated sites by one covalent bond per constituent
compound to provide the same valence as initially present at the
given site.
[0024] An example of such a cyclic derivative can be as
follows.
##STR00001##
[0025] Preferably the chromium compound is organic or inorganic
salts, coordination complexes and organometallic complexes of
Cr(II) or Cr(III)
[0026] Most preferably the chromium compound is
CrCl.sub.3(THF).sub.3, Cr(III)acetylacetonate, Cr(III)octanoate,
chromium hexacarbonyl, Cr(III)-2-ethylhexanoate,
(benzene)tricarbonyl-chromium, or a combination comprising at least
one of the foregoing.
[0027] It is also preferred that R.sub.1, R.sub.2, R.sub.3,
R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are methyl, ethyl,
isopropyl, tert-butyl, cyclohexyl, phenyl, benzyl, tolyl, xylyl, or
a combination comprising at least one of the foregoing.
[0028] In one embodiment the activator or co-catalyst is
trimethylaluminum, triethylaluminum, triisopropylaluminum,
triisobutylaluminum, ethylaluminumsesquichloride, diethylaluminum
chloride, ethylaluminumdichloride, methylaluminoxane (MMAO),
modified methylaminoxane, or a combination comprising at least one
of the foregoing.
[0029] Most preferred is a catalyst composition, wherein the ligand
is Ph.sub.2P--N(i-Pr)--P(Ph)-N(i-Pr)Ph,
Ph.sub.2P--N(i-Pr)--P(Ph)-N(Me)C.sub.6H.sub.6,
Ph.sub.2P--N(i-Pr)--P(Ph)S(i-Pr),
Ph.sub.2P--N(i-Pr)--P(Ph)OC.sub.2H.sub.5,
Ph.sub.2P--N(i-Pr)P(Ph)OCH.sub.3, or a combination comprising at
least one of the foregoing
[0030] A catalyst composition is also preferably provided
additionally comprising a solvent, preferably aromatic
hydrocarbons, straight-chain and cyclic aliphatic hydrocarbons,
straight-chain olefins and ethers, preferably toluene, benzene,
ethylbenzene, cumene, xylenes, mesitylene, hexane, octane,
cyclohexane, methylcyclohexane, hexene, heptene, octene,
diethylether, tetrahydrofuran, chlorobenzene, or a combination
comprising at least one of the foregoing, most preferably toluene
or chlorobenzene.
[0031] In one embodiment, the concentration of the chromium
compound is from 0.01 to 100 mmol/l, preferably 0.1 to 10
mmol/l.
[0032] The ligand/Cr molar ratio is preferably from 0.5 to 50,
preferably 0.8 to 2.0. The Al/Cr molar ratio preferably is from 1:1
to 1000:1, preferably 10:1 to 200:1.
[0033] As is obvious for someone skilled in the art, the components
(a) to (c) for providing the catalyst composition are more or less
considered as starting materials, but may be converted when the
free compounds (a)-(c) are mixed to form the catalyst composition.
In this regard, the catalyst composition according to the present
invention can be also illustrated as being obtainable by combining
at least (a) a chromium compound; (b) a ligand of the general
structure
[0034] (A) R.sub.1R.sub.2P--N(R.sub.3)--P(R.sub.4)--NR.sub.5R.sub.6
or
[0035] (B) R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7)R.sub.8 or
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7).sub.2, with X.dbd.O or S,
wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6,
R.sub.7 and R.sub.8 are independently C.sub.1-C.sub.10-alkyl,
C.sub.6-C.sub.20-aryl, C.sub.3-C.sub.10-cycloalkyl, aralkyl,
alkylaryl, or trialkylsilyl or any cyclic derivatives of (A) and
(B), wherein at least one of the P or N atoms of the PNPN-unit or
PNP-unit is a member of the ring system, the ring system being
formed from one or more constituent compounds of structures (A) or
(B) by substitution; and (c) an activator or co-catalyst.
[0036] According to the invention is also a process for tri- and/or
tetramerization of ethylene, comprising subjecting a catalyst
composition according to the invention to a gas phase of ethylene
in a reactor and conducting an oligomerization. Requirements and
conditions for conducting an oligomerization using an organo
metallic catalyst are well known in the art. Preferably the
oligomerization is carried out at a pressure of 1 to 200 bar,
preferably 10 to 50 bar.
[0037] Also preferred, the oligomerization is carried out at a
temperature of from 10 to 200.degree. C., preferably 20 to
100.degree. C.
[0038] In one embodiment, the process is carried out continuously,
semi-continuously or discontinuously.
[0039] Finally, the mean residence time may be from 10 minutes to
20 hours, preferably 1 to 4 hours.
[0040] Surprisingly, it was found that the inventive catalyst
composition provides the oligomerization of ethylene with a
significantly increased selectivity towards 1-octene and activity.
It was further found that based on the prior art, the respective
ligand structure can be successfully amended to increase the
1-octene selectivity. In a preferred embodiment, it was also found
that the selectivity can be further increased with suitable
co-catalysts and solvents which effect the control of the process
overall selectivity.
[0041] Further advantages and features of the present invention are
now illustrated in the following example section.
Examples
[0042] It was found that there are two substantial embodiments with
regard to the ligand. In a first embodiment, a ligand having the
structure R.sub.1R.sub.2P--N(R.sub.3)--P(R.sub.4)--NR.sub.5R.sub.6
is used. In a second embodiment, the ligand is
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7)R.sub.8 or
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7).sub.2 with X.dbd.O or S.
The ligands of the first embodiment are accessible via various
synthetic approaches that are shown below.
##STR00002##
[0043] Particular ligands of this first embodiment that were
successfully synthesized are shown also below.
##STR00003##
General Procedure for the Preparation of
pH.sub.2PN(i-Pr)P(pH)NR.sup.1R.sup.2
[0044] 2 mmol of the appropriate secondary amine was lithiated with
1.25 mL .sup.tBuLi (1.6 M in hexane) at 0.degree. C. in toluene and
stirred for 4 hours at room temperature (r.t.). Afterwards the
solution of the lithiated amine was transferred to a solution of
0.77 g (2 mmol) Ph.sub.2PN(.sup.iPr)P(Ph)Cl in toluene at 0.degree.
C. and stirred for 24 hours at r.t. The solution was filtrated and
evaporated to dryness, remaining an oil or solid, which was washed
with cold n-pentane.
[0045] In all cases, the preparation of Ph.sub.2P(.sup.iPr)NPCl was
performed as given in: Cross R. J.; Green, H. T.; Keat, R. J. Chem.
Soc. Dalton Trans. 1976, 1424-1428.
Preparation of Ph.sub.2PN(i-Pr)P(Ph)NMe.sub.2 (1)
[0046] 0.77 g (2 mmol) Ph.sub.2P(.sup.iPr)NPCl, dissolved in
toluene, was slowly transferred into a mixture of 10 mL
dimethylamine (2M in THF) and toluene at 0.degree. C. The solution
was stirred for 12 hour (h) at room temperature whereupon it became
cloudy. After evaporation of all volatile compounds, the residue
was dissolved in hot n-hexane and filtrated. While resting at
-40.degree. C., white crystals of pure
Ph.sub.2PN(.sup.iPr)P(Ph)NMe.sub.2 precipitated from the solution
(.sup.31P-NMR C.sub.6D.sub.6: 48.0; 91.0 ppm broad signals).
[0047] For example, the following additional ligands were
synthesized using this method.
Ph.sub.2PN(i-Pr)P(Ph)N(i-Pr)Ph (2)
[0048] Ph.sub.2PN(i-Pr)P(Ph)N(Me)C.sub.6H.sub.11 (3)
Oligomerization Examples
[0049] A standard ethylene oligomerization was carried out. A 300
ml pressure reactor, equipped with dip tube, thermowell, gas
entrainment stirrer, cooling coil, control units for temperature,
pressure, and stirrer speed (all hooked up to a data acquisition
system) was inertized with dry argon. The isobaric ethylene supply
was maintained by an aluminum pressurized gas cylinder on a balance
to monitor the ethylene consumption over time by means of a
computerized data acquisition system.
[0050] Before conducting an experiment, the reactor was heated to
100.degree. C. at reduced pressure for several hours to eliminate
traces of water, oxygen and oxygenated impurities.
[0051] For the catalyst preparation, the suitable amounts of the
ligands and chromium precursor were weighed in and charged to a
Schlenk tube under inert atmosphere. A volume of 75 ml anhydrous
solvent was added and the solution was stirred by means of a
magnetic stirrer. After dissolving the Cr-compound and ligand, 5 ml
of a solution of MMAO-3A (7 wt % Al in heptane) was added. The
solution was immediately transferred to the reactor and the
reaction was started. The reaction was stopped either when the
maximum uptake of ethylene (80 g) was reached or after a set time
by closing the ethylene inlet valve, cooling to room temperature,
depressurising and opening the reactor.
[0052] The liquid product mixture was quenched with diluted HCl and
analysed using gas chromatography with a known amount of
dodecahydrotriphenylene as internal standard. The solids were
filtered, dried and weighed.
[0053] The results of the catalytic performance tests are shown in
Table 1. In particular, Table 1 shows the results of catalytic
tests using ligands of the PNPN(R')(R'') type, where the standard
reaction conditions were: p.sub.ethylene=30 bar, T=60.degree. C.,
co-catalyst=5 mL MMAO-3A (7 wt % Al in heptane, approx. composition
[(CH.sub.3).sub.0.7(iC.sub.4H.sub.9).sub.0.3AlO].sub.n), 75 mL
solvent, [Cr]=0.034 mmol, [Ligand]/[Cr]=1.25 mol/mol.
TABLE-US-00001 TABLE 1 Ligand solvent t in min g products g solids
C4 C6 (1-C6) C8 (1-C8) C10+ 1 C.sub.6H.sub.5Cl 40 80 5.4 1.0 40.2
(95) 44.0 (99.3) 14.8 1 toluene 55 42 1.9 1.6 34.7 (93.6) 53.8
(99.3) 9.9 2 C.sub.6H.sub.5Cl 35 80 0.15 0.9 71.7 (97.6) 13.5
(99.3) 13.9 3* C.sub.6H.sub.5Cl 15 80 traces 0.8 50.1 (96.5) 34.1
(99.4) 15 3* toluene 50 80 0.08 0.8 38.8 (95.5) 47.9 (99.4) 12.5
3** C.sub.6H.sub.5Cl 35 80 1.9 0.9 45.8 (92.6) 37.6 (99.1) 15.7 C4,
C6, C8, C10+ wt % in the liquid fraction; *Cr: 0.015 mmol; **6.25
mL MAO (10 wt % in toluene) **The MMAO-3A was replaced by regular,
i.e. non-modified, MAO.
[0054] The values in the columns of C4, C6, C8 and C10+ are the
respective yields in weight percent. The values in brackets in
these columns are the respective selectivities (in weight percent)
of the C6 or C8 fraction, respectively. For example, in Table 1,
for Ligand 1, the C8 column means that the product from the
reaction contains 44.0 weight percent C8, wherein 99.3 weight
percent of this C8 fraction consists of 1-octene.
[0055] The results show that the homogeneous catalyst systems
formed showed favorable selectivities to 1-hexene and 1-octene,
where the C6/C8 ratio can be adjusted by the nature of the
substituents on the terminal N and preferably by the solvent.
[0056] According to the second embodiment, ligands according to
structure (B) were used.
[0057] Ligands of the following structure were, amongst others,
synthesized:
##STR00004##
[0058] Preparation details of some ligands of the second embodiment
are as follows.
Synthesis of the PNP(OR)/PNP(SR)--ligands: Preparation of
Ph.sub.2PN(.sup.iPr)P(Ph)S(.sup.iPr) (A)
[0059] 0.77 g (2 mmol) Ph.sub.2P(.sup.iPr)NPCl, dissolved in
toluene, was slowly transferred into a mixture of 0.381 g (5 mmol)
2-propanethiol, 1 mL (7 mmol) triethylamine and toluene at r.t. The
solution was stirred for 24 hrs at 40.degree. C., whereupon it
became cloudy. After filtration and evaporation of all volatile
compounds a colorless oil remained. (.sup.31P-NMR C.sub.6D.sub.6:
46.4 ppm broad; 91.7 ppm d; J=26 Hz)
Preparation of Ph.sub.2PN(.sup.iPr)P(Ph)OEt (B)
[0060] A mixture of 0.77 g (2 mmol) Ph.sub.2PN(.sup.iPr)P(Ph)Cl, 1
mL (7 mmol) triethylamine, 0.233 mL (4 mmol) ethanol and toluene
was stirred at 50.degree. C. for 6 days. The turbid solution was
filtrated and evaporated to dryness to yield a colorless oil.
(.sup.31P-NMR CDCl.sub.3: 39.5 ppm broad; 129.7 ppm d, J=20.6
Hz)
Preparation of Ph.sub.2PN(.sup.iPr)P(Ph)OMe (C)
[0061] A mixture of 0.77 g (2 mmol) Ph.sub.2PN(.sup.iPr)P(Ph)Cl, 1
mL (7 mmol) triethylamine, 0.162 mL (4 mmol) methanol and toluene
was stirred at 50.degree. C. for 2 days. The turbid solution was
filtrated and evaporated to dryness to yield a colorless oil.
(.sup.31P-NMR CDCl.sub.3: 36.3 ppm broad; 133.3 ppm d, J=19.6
Hz)
[0062] The preparation of Ph.sub.2P(.sup.iPr)NPCl was performed
according to: Cross R. J.; Green, H. T.; Keat, R. J. Chem. Soc.
Dalton Trans. 1976, 1424-1428.
[0063] The catalytic oligomerization tests were carried out
following the experimental procedure described above.
[0064] The results of the catalytic performance tests are shown in
Table 2. The homogeneous catalyst systems showed favorable
selectivities to 1-hexene and 1-octene. In Table 2, standard
reaction conditions are: p.sub.ethylene=30 bar, T=60.degree. C.,
co-catalyst=5 mL MMAO-3A (7 wt % Al in heptane), 75 mL solvent,
[Cr]=0.034 mmol, [Ligand]/[Cr]=1.25.
TABLE-US-00002 TABLE 2 Ligand solvent t in min g products g solids
C4 C6 (1-C6) C8 (1-C8) C10+ A C.sub.6H.sub.5Cl 60 18 1.65 1.1 38.4
(90) 47.6 (99) 12.9 B C.sub.6H.sub.5Cl 55 80 4.7 1.3 45.0 (92.3)
39.6 (98.9) 15.1 B* C.sub.6H.sub.5Cl 35 80 7.5 0.9 45.8 (92.5) 37.6
(99.1) 15.7 C C.sub.6H.sub.5Cl 50 80 3.5 1.2 40.0 (86.5) 44.9
(98.8) 13.9 C* C.sub.6H.sub.5Cl 50 80 7.0 1.4 36.4 (86.2) 46.5 (99)
15.6 C4, C6, C8, C10+ wt % in the liquid fraction; *6.25 mL MAO (10
wt % in toluene) *MMAO-3A has been replaced by regular, i.e.,
non-modified, MAO.
[0065] In summary, a catalyst composition comprises: (a) a chromium
compound, preferably wherein the chromium compound is an organic or
inorganic salt, a coordination complex, or an organometallic
complexes of Cr(II) or Cr(III), or more preferably
CrCl.sub.3(THF).sub.3, Cr(III)acetylacetonate, Cr(III)octanoate,
chromium hexacarbonyl, Cr(III)-2-ethylhexanoate,
(benzene)tricarbonyl-chromium, or a combination comprising at least
one of the foregoing; (b) a ligand of the general structure
[0066] (A) R.sub.1R.sub.2P--N(R.sub.3)--P(R.sub.4)--NR.sub.5R.sub.6
or
[0067] (B) R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7)R.sub.8 or
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7).sub.2,
wherein X.dbd.O or S and R.sub.1, R.sub.2, R.sub.3, R.sub.4,
R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are independently
C.sub.1-C.sub.10-alkyl, C.sub.6-C.sub.20-aryl,
C.sub.3-C.sub.10-cycloalkyl, aralkyl, alkylaryl, or trialkylsilyl,
or any cyclic derivatives of (A) and (B), wherein at least one of
the P or N atoms of the PNPN-unit or PNP-unit is a member of the
ring system, the ring system being formed from one or more
constituent compounds of structures (A) or (B) by substitution,
preferably wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5,
R.sub.6, R.sub.7 and R.sub.8 are methyl, ethyl, isopropyl,
tert-butyl, cyclohexyl, phenyl, benzyl, tolyl, or xylyl; and (c) an
activator or co-catalyst, preferably wherein the activator or
co-catalyst is trimethylaluminum, triethylaluminum,
triisopropylaluminum, triisobutylaluminum,
ethylaluminumsesquichloride, diethylaluminum chloride,
ethylaluminumdichloride, methylaluminoxane (MAO), modified
methylaminoxane (MMAO), or a combination comprising at least one of
the foregoing; and more preferably wherein the ligand (A) is
Ph.sub.2P--N(i-Pr)--P(Ph)-N(i-Pr)Ph,
Ph.sub.2P--N(i-Pr)--P(Ph)-N(Me)C.sub.6H.sub.6,
Ph.sub.2P--N(i-Pr)--P(Ph)S(i-Pr),
Ph.sub.2P--N(i-Pr)--P(Ph)OC.sub.2H.sub.5,
Ph.sub.2P--N(i-Pr)P(Ph)OCH.sub.3, or a combination comprising at
least one of the foregoing; optionally wherein one or more of the
following conditions applies: the catalyst composition additionally
comprises a solvent, preferably an aromatic hydrocarbon,
straight-chain aliphatic hydrocarbon, cyclic aliphatic hydrocarbon,
straight-chain olefin, straight-chain ether, or a combination
comprising at least one of the foregoing, more preferably toluene,
benzene, ethylbenzene, cumene, xylenes, mesitylene, hexane, octane,
cyclohexane, methylcyclohexane, hexene, heptene, octene,
diethylether, tetrahydrofuran, chlorobenzene, or a combination
comprising at least one of the foregoing, and most preferably
toluene or chlorobenzene; the concentration of the chromium
compound is from 0.01 to 100 mmol/1, preferably 0.1 to 10 mmol/1;
the ligand/Cr molar ratio is from 0.5 to 50, preferably 0.8 to 2.0;
and the Al/Cr molar ratio is from 1:1 to 1000:1, preferably 10:1 to
200:1.
[0068] A process for the manufacture of the foregoing catalyst
composition comprises combining: a) a chromium compound, preferably
wherein the chromium compound is an organic or inorganic salt, a
coordination complex, or an organometallic complexes of Cr(II) or
Cr(III), or more preferably CrCl.sub.3(THF).sub.3,
Cr(III)acetylacetonate, Cr(III)octanoate, chromium hexacarbonyl,
Cr(III)-2-ethylhexanoate, (benzene)tricarbonyl-chromium, or a
combination comprising at least one of the foregoing; (b) a ligand
of the general structure
[0069] (A) R.sub.1R.sub.2P--N(R.sub.3)--P(R.sub.4)--NR.sub.5R.sub.6
or
[0070] (B) R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7)R.sub.8 or
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7).sub.2,
wherein X.dbd.O or S and R.sub.1, R.sub.2, R.sub.3, R.sub.4,
R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are independently
C.sub.1-C.sub.10-alkyl, C.sub.6-C.sub.20-aryl,
C.sub.3-C.sub.10-cycloalkyl, aralkyl, alkylaryl, or trialkylsilyl,
or any cyclic derivatives of (A), or (B), wherein at least one of
the P or N atoms of the PNPN-unit or PNP-unit is a member of the
ring system, the ring system being formed from one or more
constituent compounds of structures (A) or (B) by substitution,
preferably wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5,
R.sub.6, R.sub.7, or R.sub.8 are methyl, ethyl, isopropyl,
tert-butyl, cyclohexyl, phenyl, benzyl, tolyl, xylyl, or a
combination comprising at least one of the foregoing; and (c) an
activator or co-catalyst, preferably wherein the activator or
co-catalyst is trimethylaluminum, triethylaluminum,
triisopropylaluminum, triisobutylaluminum,
ethylaluminumsesquichloride, diethylaluminum chloride,
ethylaluminumdichloride, methylaluminoxane (MAO), modified
methylaminoxane (MMAO), or a combination comprising at least one of
the foregoing; more preferably wherein the ligand (A) is
Ph.sub.2P--N(i-Pr)--P(Ph)-N(i-Pr)Ph,
Ph.sub.2P--N(i-Pr)--P(Ph)-N(Me)C.sub.6H.sub.6,
Ph.sub.2P--N(i-Pr)--P(Ph)S(i-Pr),
Ph.sub.2P--N(i-Pr)--P(Ph)OC.sub.2H.sub.5,
Ph.sub.2P--N(i-Pr)P(Ph)OCH.sub.3, or a combination comprising at
least one of the foregoing; optionally wherein one or more of the
following conditions applies: a solvent is optionally combined,
preferably an aromatic hydrocarbon, straight-chain, or cyclic
aliphatic hydrocarbon, straight-chain olefin, straight-chain ether,
or a combination comprising at least one of the foregoing more
preferably toluene, benzene, ethylbenzene, cumene, xylenes,
mesitylene, hexane, octane, cyclohexane, methylcyclohexane, hexene,
heptene, octene, diethylether, tetrahydrofurane, chlorobenzene, or
a combination comprising at least one of the foregoing, and most
preferably toluene or chlorobenzene; the concentration of the
chromium compound is from 0.01 to 100 mmol/1, preferably 0.1 to 10
mmol/1; the ligand/Cr molar ratio is from 0.5 to 50, preferably 0.8
to 2.0; and the Al/Cr molar ratio is from 1:1 to 1000:1, preferably
10:1 to 200:1.
[0071] A process for tri- and/or tetramerization of ethylene,
comprises subjecting a catalyst composition to a gas phase of
ethylene in a reactor and conducting an oligomerization, wherein
the catalyst composition comprises a) a chromium compound,
preferably wherein the chromium compound is an organic or inorganic
salt, a coordination complex, or an organometallic complexes of
Cr(II) or Cr(III), or more preferably CrCl.sub.3(THF).sub.3,
Cr(III)acetylacetonate, Cr(III)octanoate, chromium hexacarbonyl,
Cr(III)-2-ethylhexanoate, (benzene)tricarbonyl-chromium, or a
combination comprising at least one of the foregoing; (b) a ligand
of the general structure
[0072] (A) R.sub.1R.sub.2P--N(R.sub.3)--P(R.sub.4)--NR.sub.5R.sub.6
or
[0073] (B) R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7)R.sub.8 or
R.sub.1R.sub.2P--N(R.sub.3)--P(XR.sub.7).sub.2,
wherein X.dbd.O or S and R.sub.1, R.sub.2, R.sub.3, R.sub.4,
R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are independently
C.sub.1-C.sub.10-alkyl, C.sub.6-C.sub.20-aryl,
C.sub.3-C.sub.10-cycloalkyl, aralkyl, alkylaryl, or trialkylsilyl,
or any cyclic derivatives of (A) and (B), wherein at least one of
the P or N atoms of the PNPN-unit or PNP-unit is a member of the
ring system, the ring system being formed from one or more
constituent compounds of structures (A) or (B) by substitution,
preferably wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5,
R.sub.6, R.sub.7 and R.sub.8 are methyl, ethyl, isopropyl,
tert-butyl, cyclohexyl, phenyl, benzyl, tolyl, xylyl, or a
combination comprising at least one of the foregoing; and (c) an
activator or co-catalyst, preferably wherein the activator or
co-catalyst is trimethylaluminum, triethylaluminum,
triisopropylaluminum, triisobutylaluminum,
ethylaluminumsesquichloride, diethylaluminum chloride,
ethylaluminumdichloride, methylaluminoxane (MAO), modified
methylaminoxane (MMAO), or a combination comprising at least one of
the foregoing; and more preferably wherein the ligand (A) is
Ph.sub.2P--N(i-Pr)--P(Ph)-N(i-Pr)Ph,
Ph.sub.2P--N(i-Pr)--P(Ph)-N(Me)C.sub.6H.sub.6,
Ph.sub.2P--N(i-Pr)--P(Ph)S(i-Pr),
Ph.sub.2P--N(i-Pr)--P(Ph)OC.sub.2H.sub.5, or
Ph.sub.2P--N(i-Pr)P(Ph)OCH.sub.3, or a combination comprising at
least one of the foregoing; optionally wherein one or more of the
following conditions applies: the catalyst composition additionally
comprises a solvent, preferably an aromatic hydrocarbon,
straight-chain and cyclic aliphatic hydrocarbon, straight-chain
olefin, straight-chain ether, or a combination comprising at least
one of the foregoing, more preferably toluene, benzene,
ethylbenzene, cumene, xylenes, mesitylene, hexane, octane,
cyclohexane, methylcyclohexane, hexene, heptene, octene,
diethylether, tetrahydrofuran, chlorobenzene, or a combination
comprising at least one of the foregoing, and most preferably
toluene or chlorobenzene; the concentration of the chromium
compound is from 0.01 to 100 mmol/1, preferably 0.1 to 10 mmol/1;
the ligand/Cr molar ratio is from 0.5 to 50, preferably 0.8 to 2.0;
and the Al/Cr molar ratio is from 1:1 to 1000:1, preferably 10:1 to
200:1; the oligomerization is carried out at a pressure of 1 to 200
bar, preferably 10 to 50 bar; the oligomerization is carried out at
a temperature of from 10 to 200.degree. C., preferably 20 to
100.degree. C.; and the mean residence time is from 10 minutes to
20 hours, preferably 1 to 4 hours during oligomerization.
[0074] The singular forms "a", "an", and "the" include plural
referents unless the context clearly dictates otherwise. "Or" means
"and/or". The endpoints of all ranges directed to the same
component or property are inclusive and independently combinable
(e.g., ranges of "less than or equal to 25 wt %, or 5 wt % to 20 wt
%," is inclusive of the endpoints and all intermediate values of
the ranges of "5 wt % to 25 wt %," etc.). Disclosure of a narrower
range or more specific group in addition to a broader range is not
a disclaimer of the broader range or larger group. Unless defined
otherwise, technical and scientific terms used herein have the same
meaning as is commonly understood by one of skill in the art to
which this invention belongs. A "combination" is inclusive of
blends, mixtures, alloys, reaction products, and the like.
[0075] As used herein, the term "hydrocarbyl" and "hydrocarbon"
refers broadly to a substituent comprising carbon and hydrogen,
optionally with 1 to 3 heteroatoms, for example, oxygen, nitrogen,
halogen, silicon, sulfur, or a combination thereof; "alkyl" refers
to a straight or branched chain, saturated monovalent hydrocarbon
group; "alkylene" refers to a straight or branched chain,
saturated, divalent hydrocarbon group; "alkylidene" refers to a
straight or branched chain, saturated divalent hydrocarbon group,
with both valences on a single common carbon atom; "alkenyl" refers
to a straight or branched chain monovalent hydrocarbon group having
at least two carbons joined by a carbon-carbon double bond;
"cycloalkyl" refers to a non-aromatic monovalent monocyclic or
multicylic hydrocarbon group having at least three carbon atoms,
"cycloalkenyl" refers to a non-aromatic cyclic divalent hydrocarbon
group having at least three carbon atoms, with at least one degree
of unsaturation; "aryl" refers to an aromatic monovalent group
containing only carbon in the aromatic ring or rings; "arylene"
refers to an aromatic divalent group containing only carbon in the
aromatic ring or rings; "alkylaryl" refers to an aryl group that
has been substituted with an alkyl group as defined above, with
4-methylphenyl being an exemplary alkylaryl group; "arylalkyl"
refers to an alkyl group that has been substituted with an aryl
group as defined above, with benzyl being an exemplary arylalkyl
group; "acyl" refers to an alkyl group as defined above with the
indicated number of carbon atoms attached through a carbonyl carbon
bridge (--C(.dbd.O)--); "alkoxy" refers to an alkyl group as
defined above with the indicated number of carbon atoms attached
through an oxygen bridge (--O--); and "aryloxy" refers to an aryl
group as defined above with the indicated number of carbon atoms
attached through an oxygen bridge (--O--).
[0076] Unless otherwise indicated, each of the foregoing groups can
be unsubstituted or substituted, provided that the substitution
does not significantly adversely affect synthesis, stability, or
use of the compound. The term "substituted" as used herein means
that at least one hydrogen on the designated atom or group is
replaced with another group, provided that the designated atom's
normal valence is not exceeded. When the substituent is oxo (i.e.,
.dbd.O), then two hydrogens on the atom are replaced. Combinations
of substituents and/or variables are permissible provided that the
substitutions do not significantly adversely affect synthesis or
use of the compound. Exemplary groups that can be present on a
"substituted" position include, but are not limited to, cyano;
hydroxyl; nitro; azido; alkanoyl (such as a C.sub.2-6 alkanoyl
group such as acyl); carboxamido; C.sub.1-6 or C.sub.1-3 alkyl,
cycloalkyl, alkenyl, and alkynyl (including groups having at least
one unsaturated linkages and from 2 to 8, or 2 to 6 carbon atoms);
C.sub.1-6 or C.sub.1-3 alkoxys; C.sub.6-10 aryloxy such as phenoxy;
C.sub.1-6 alkylthio; C.sub.1-6 or C.sub.1-3 alkylsulfinyl; C1-6 or
C.sub.1-3 alkylsulfonyl; aminodi(C.sub.1-6 or C.sub.1-3)alkyl;
C.sub.6-12 aryl having at least one aromatic rings (e.g., phenyl,
biphenyl, naphthyl, or the like, each ring either substituted or
unsubstituted aromatic); C.sub.7-19 arylalkyl having 1 to 3
separate or fused rings and from 6 to 18 ring carbon atoms; or
arylalkoxy having 1 to 3 separate or fused rings and from 6 to 18
ring carbon atoms, with benzyloxy being an exemplary
arylalkoxy.
[0077] All cited patents, patent applications, and other references
are incorporated herein by reference in their entirety. However, if
a term in the present application contradicts or conflicts with a
term in the incorporated reference, the term from the present
application takes precedence over the conflicting term from the
incorporated reference.
[0078] The features disclosed in the foregoing description, in the
claims and/or in the accompanying drawings may, both separately and
in any combination thereof, be material for realizing the invention
in diverse forms thereof.
* * * * *