EVONIK DEGUSSA GMBH

Patent Trials and Appeals Board

Jul 1, 2020

2019005531 (P.T.A.B. Jul. 1, 2020)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
15/213,444 07/19/2016 Kaiwu DONG 032301 R 841 4300
441 7590 07/01/2020
SMITH, GAMBRELL & RUSSELL, LLP
1055 Thomas Jefferson Street
Suite 400
WASHINGTON, DC 20007
EXAMINER
O DELL, DAVID K
ART UNIT PAPER NUMBER
1625
NOTIFICATION DATE DELIVERY MODE
07/01/2020 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
docketing@sgrlaw.com
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte KAIWU DONG, XIANGJIE FANG,
HELFRIED NEUMANN, RALF JACKSTELL,
MATTHIAS BELLER, ROBERT FRANKE, DIETER HESS,
KATRIN MARIE DYBALLA, DIRK FRIDAG, and FRANK GEILEN
Appeal 2019-005531
Application 15/213,444
Technology Center 1600
Before ERIC B. GRIMES, RICHARD M. LEBOVITZ, and
TAWEN CHANG, Administrative Patent Judges.
CHANG, Administrative Patent Judge.
DECISION ON APPEAL
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 1 and 7. We have jurisdiction under
35 U.S.C. § 6(b).
We AFFIRM.

1 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42. Appellant identifies the real party in interest as Evonik
Degussa GMBH. Appeal Br. 2.
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STATEMENT OF THE CASE
“[A]lkoxycarbonylation is . . . the reaction of ethylenically
unsaturated compounds (olefins) with carbon monoxide and alcohols in the
presence of a metal-ligand complex to give the corresponding esters,” as
illustrated below:

Spec. 1:7–14. The scheme reproduced above depicts “the general reaction
equation of an alkoxycarbonylation.” Id. at 1:10–14. “Typically, the metal
used is palladium” and “bidentate diphosphine compounds are used . . . as
ligands.” Id. at 1:9–10, 22.
According to the Specification, the invention “provid[es] novel
ligands for alkoxycarbonylation” that achieves good yields of esters and are
“suitable for the alkoxycarbonylation of long-chain ethylenically unsaturated
compounds, for example C8 olefins, and of mixtures of ethylenically
unsaturated compounds.” Spec. 2:7–11. In particular, the Specification
teaches “butyl-bridged diphosphine compounds substituted by at least one
heteroaryl radical on at least one phosphorus atom.” Id. at 2:13–14.

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CLAIMED SUBJECT MATTER
Claims 1 and 7, the only claims on appeal, are reproduced below:
1. A compound capable of binding palladium having formula (I)

where
R1 and R3 are each a heteroaryl having 6-10 ring atoms;
and R2 and R4 are independently selected from -(C1-C4)-alkyl.

7. Compound according to claim 1, of the formula (1)

Appeal Br. 12 (Claims App.).2

2 As listed in the Claims Appendix, claim 1 does not include the limitation
“capable of binding palladium.” Appeal Br. 12 (Claims App.). However,
the limitation was added in Appellant’s December 18, 2018 Response under
37 C.F.R. § 1.114, and the claims do not appear to have been amended
subsequently to remove the limitation. Both Appellant and the Examiner
also make arguments based on the limitation in the Appeal Brief and
Answer, respectively. Accordingly, we understand that the limitation was
inadvertently omitted in the Claims Appendix.
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REJECTION(S)
A. Claims 1 and 7 are rejected under 35 U.S.C. § 103 as being
unpatentable over Kodama,3 Wislicenus,4 and Hill.5 Ans. 3.
B. Claim 1 is rejected on the judicially-created basis that it contains an
improper Markush grouping of alternatives. Ans. 7.

OPINION
A. Obviousness rejection over Kodama, Wislicenus, and Hill (claims
1 and 7)
1. Issue
As an initial matter, the Examiner concludes that the preamble
limitation, “capable of binding palladium,” is functional language that
carries no patentable weight in claims for compositions of matter. Ans. 7.
The Examiner next finds that Kodama teaches bisphosphines of formula (2),
reproduced below, for making complexes of Au, Ag, Cu, or Pt for treating
cancer:

Ans. 3–4. The Examiner finds that Kodama teaches that
R1s and R3s each represent an alkyl group, a cycloalkyl group,
an aryl group, an aralkyl group, a pyridyl group, or a pyrimidyl
group; R2s and R4s each represent an alkyl group or a

3 Kodama et al., US 8,106,186 B2, issued Jan. 31, 2012.
4 Johannes Wislicenus, ADOLPH STRECKER’S SHORT TEXT-BOOK OF
ORGANIC CHEMISTRY (W.R. Hodgkinson & A.J. Greenaway trans., 1881).
5 Hill et al., EP 0 198 696, published Oct. 22, 1986.
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cycloalkyl group, provided that each R1 and each R2 are not the
same group and that each R3 and each R4 are not the same
group; As each represent a linear alkylene group....The present
invention also provides the transition metal phosphine complex
in [w]hich R1s and R3s each represent a pyridyl group....
Id. at 4.
The Examiner finds that Hill also discloses various “butyl bridged bis-
phosphine compounds” that are used as ligands to make various Au
complexes useful for treating cancers. Ans. 4–5.
The Examiner finds that Kodama discloses a specific compound, 1,2-
bis(tert-butyl(2-pyridyl)phosphino)ethane, that differs from the compound of
claim 7, 2-bis(tert-butyl(2-pyridyl)phosphino)butane, by two methylene
groups, as shown below:

Ans. 5, 10–11. The Examiner finds that, thus, Kodama discloses an alkyl
homolog of the compound of claim 7.
The Examiner concludes that a skilled artisan would find the
compound of claim 7 obvious because “[h]omologs have long been known
to exhibit similar properties as evidenced by . . . Wislicenus,” and a skilled
artisan “would expect the compounds to have similar properties.” Ans. 6.
The Examiner further cites to case law holding “[a]nalogs differing only in a
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single methylene in an alkyl chain . . . to be prima facie obvious,” and to
Kodama’s teaching that for purposes of its invention “As . . . represent a
linear alkylene group,” which is described generically as “an ethylene group,
a trimethylene group, a tetramethylene group.” Id. at 6–7. The Examiner
explains that “[t]he tetramethylene group is butyl.” Id. at 7.
Finally, the Examiner finds that a skilled artisan would have a
reasonable expectation of success at arriving at the claimed invention,
because, “as can be seen by the Hill disclosure, preparing and making the
complexes of all the alkyl congeners for these phosphine ligands is routine
in the anti-cancer phosphine complex art” and “[a]ll of the alkyl homologs
give the requisite complexes.” Ans. 7.
Appellant contends that the Examiner has not pointed to guidance that
would have lead a skilled artisan to arrive at the claimed invention from the
teachings of the prior art, with a reasonable expectation of success. Appeal
Br. 4; Reply Br. 2–3. Appellant contends that the Examiner’s rejection is
based on improper hindsight, improperly relied on inherency with respect to
the limitation regarding palladium binding, and did not take due account of
the unexpected results presented in the Specification. Reply Br. 3–4.
Finally, Appellant contends that Kodama’s phosphine ligand is “solely
useful as an intermediate” for preparing the final anti-cancer agent; thus, “no
activity [is] expected to be ‘maintained’ for the . . . homologue[s].” Id. at 3.
The issue with respect to this rejection is whether a preponderance of
evidence supports the Examiner’s conclusion that the compound disclosed in
Example 1 of Kodama, in combination with the remaining teachings of
Kodama, Hill, and Wislicenus, renders obvious the claims on appeal.
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2. Findings of Fact
1. Kodama teaches
a novel transition metal phosphine complex having excellent
anticancer activity. The transition metal phosphine complex is
represented by general formula (1):

(wherein R1s and R3s each represent an alkyl group, a
cycloalkyl group, an aryl group, an aralkyl group, a pyridyl
group, or a pyrimidyl group; R2s and R4s each represent an
alkyl group or a cycloalkyl group, provided that each R1 and
each R2 are not the same group and that each R3 and each R4 are
not the same group; As each represent a linear alkylene group
or a cis-vinylene group; M represents a gold atom, a silver
atom, a copper atom, or a platinum atom; and B represents an
anionic species).
Kodama Abstract; see also id. at 1:9–12, 2:1–6.
2. Kodama teaches that, with respect to its preferred embodiments,
the A in general formula (1) represents “a linear alkylene group or a cis-
vinylene group” and that, where A is a linear alkylene group, an alkylene
group having 1 to 5 carbon atoms (e.g., a methylene group, an ethylene
group, a trimethylene group, a tetramethylene group, and a pentamethylene
group) is suitable, even though “[a]n ethylene group is preferred.” Kodama
4:30–35.
3. Kodama teaches “[a] method for producing the transition metal
phosphine complex of [its] invention” by “allowing a bisphosphine
derivative represented by general formula (2)
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(wherein R1 to R4 and A have the same meanings as defined above) to react
with a transition metal salt of gold, copper, platinum, or silver.” Id. at 5:22–
38. Kodama teaches that “[t]he bisphosphine derivative represented by
general formula (2) is a starting material and may be produced by a known
method.” Id. at 5:39–41.
4. Kodama teaches 4 example compounds and 1 comparative
example compound. Examples 1–3 of Kodama teach the synthesis of
racemic, meso, and R,R forms of bis(1,2-bis(tert-butyl(2-
pyridyl)phosphino)ethane)gold(I) chloride (Compounds (1)–(3)) from
stereoisomers of 1,2-bis(tert-butyl(2-pyridyl)phosphino)ethane. Kodama
11:15–12:26, 15:14–27 (Table 1). Example 4 teaches the synthesis of
bis(R,R)-1,2-bis(tert-butyl(2-pyrimidyl)phosphino)ethane)gold(I) chloride.
Id. at 12:60–13:26, 15:14–27 (Table 1). Comparative Example 1 teaches the
synthesis of bis[1,2-bis(phenyl(2-pyridyl)phosphino)ethane]gold(I) chloride
(Compound (5)) from 1,2-bis(phenyl(2-pyridyl)phosphino)ethane. Id. at
14:55–15:13, 15:14–27 (Table 1).
5. The Examiner finds, and Appellant does not dispute, that 1,2-
bis(tert-butyl(2-pyridyl)phosphino)ethane differs from the compound of
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claim 7 only by two methylene groups in the alkyl bridge between the
phosphorous atoms, as shown below:

Ans. 5, 10–11.
6. Kodama teaches that compounds (1)–(3), i.e., the transition
metal-phosphine complex discussed above, have excellent water solubility;
excellent anticancer properties compared with cisplatin, a known anticancer
agent; and low toxicity. Kodama 15:28–16:67, 17:31–18:7.
7. Hill teaches
[p]harmaceutical compositions containing compounds of structure
(III)

in which R2 is the same and is phenyl, ethyl or 2-pyridyl, A is C1-6
alkanediyl chain, Y is a link of structure:

where X1 is halo, and their use in therapy for inhibiting the growth of
animal tumor cells. Intermediates used in the preparation of
compounds (III), compositions containing them and their use in
therapy for inhibiting the growth of animal tumor cells.
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Hill Abstract (formatting added); see also id. at 10:32–11:25.
8. Hill also teaches
compounds of the formula:

wherein:
R is the same and is 2-pyridyl, 4-pyridyl, 2-thienyl or 2-furyl;
X is the same and is halo or thiosugar;
M is 0 or 1, provided that when M is 1, R is 2-pyridyl or 4-
pyridyl; and
A is a straight or branched alkanediyl chain of from one to six
carbon atoms.
When X is thiosugar, the attachment of X to the gold atom is through
the sulfur atom of the thiosugar.
Hill 2:23–3:5. Hill teaches that compounds of formula (I) also inhibit tumor
growth. Id. at 9:32–10:31.
9. Hill teaches that “[a]ll the compounds of Formulas (I) . . . and
(III) can be prepared by methods available to one skilled in the art.” Hill
4:35–5:2.
10. Hill teaches example compounds of Formulas (I) and (III)
wherein A is a butyl bridge, including some in which R or R2 are 2-pyridyl
groups. See, e.g. Hill 17:16 (1,2-Bis(di-2-pyridylphosphino)butane), 20:11
(dichlorobis[l,2-bis(diphenylphosphino)butane]digold), 24:8–9 (μ-[l,4-
Bis(di-2-pyridylphosphino)butane]bis(chlorogold)), 25:8–9 (chlorobis-[l,4-
bis(di-2-pyridylphosphino)butane]gold), 25:28–29 (μ-[l,4-bis(di-2-
pyridylphosphino)butane]bis-(1-thio-ß-D-glucopyranosato-S)gold).
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11. Wislicenus teaches that “bodies of different molecular
composition frequently exhibit great similarity in all their chemical and
physical properties” and that “[t]he compounds in which these analogies are
most marked are those whose formulae differ by CH2, or a whole multiple
thereof, nCH2.” Wislicenus 38.
12. Wislicenus teaches that “[t]he similarity of physical properties
between the members of a homologous series is greater . . . the less they
differ in chemical composition.” Wislicenus 38.
3. Analysis
Except as otherwise noted, we adopt the Examiner’s findings of fact
and reasoning regarding the scope and content of the prior art (Final Act. 2–
4, 6–10, FF1–FF12) and agree that claims 1 and 7 are obvious over Kodama,
Wislicenus, and Hill. We address Appellant’s arguments below. Only those
arguments made by Appellant in the briefs have been considered; arguments
not presented in the briefs are waived. See 37 C.F.R. § 41.37(c)(1)(iv).
Appellant contends that the claims are “directed to butyl-bridged
diphosphine ligands capable of complexing with palladium in a reaction
mixture to form an active catalyst suitable for alkoxycarbonylation.” Appeal
Br. 4. Appellant contends that the Examiner has not pointed to “[g]uidance
that would have led one to the necessary substituents for
alkoxycarbonylation activity” and that “[t]here is also no reasonable
expectation of success of achieving alkoxycarbonylation catalytic activity.”
Id. (emphasis omitted).
We are not persuaded. As an initial matter, the claims are directed to
a compound and do not recite any limitations relating to
alkoxycarbonylation. Thus, it is not necessary for a prior art reference to
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suggest alkoxycarbonylation catalytic activity in order to render the claims
obvious. Similarly, because the prior art combination renders obvious the
compound recited in claim 7, the claim element “capable of binding
palladium” is inherently met. See, e.g., Abbott Labs. v. Baxter Pharm.
Products, Inc., 471 F.3d 1363, 1368 (Fed. Cir. 2006) (“The general principle
that a newly-discovered property of the prior art cannot support a patent on
that same art is not avoided if the patentee explicitly claims that property.”).
Appellant contends that there is no guidance in the prior art for
selecting the compound of Kodama’s Example 1 as a lead compound, no
teaching in the art that “a ligand with a ‘butyl bridge’ . . . would have
anticancer activity,” no discussion of how “the alkyl bridge length impacts
transitional metal binding,” and no suggestion that “increasing the length of
an ethyl bridge,” such as that found in the compound of Kodama’s Example
1, “would have a positive effect on anticancer activity.” Reply Br. 2–3.
We are not persuaded. Kodama teaches that the compound of its
Example 1 (i.e., compound 1) has excellent water solubility; excellent
anticancer properties compared with cisplatin, a known anticancer agent;
and low toxicity. FF4, FF6. Thus, to the extent a lead compound analysis is
applicable in this case, a skilled artisan would have had reason, based on the
guidance provided in Kodama, to choose the compound of Kodama’s
Example 1 as a lead compound.
Likewise, the teachings in the prior art provide a motivation for a
skilled artisan to arrive at the claimed compound, with a reasonable
expectation of success. Kodama’s Example 1 teaches a compound that
differs from the compound recited in claim 7 only in two methylene groups
in the alkyl bridges connecting the phosphorus atoms. FF5. That is, the
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compound of Kodama’s Example 1 contains an ethyl bridge, whereas the
compound of claim 7 contains a butyl bridge, and the formulas of the two
compounds thus differ by -C2H4-. Id.
It is known in the prior art that compounds whose formula differ by
multiple of CH2 “frequently exhibit great similarity in all their chemical and
physical properties.” FF11, FF12. More importantly, Kodama explicitly
teaches that, with respect to preferred embodiments of its anticancer
transition metal phosphine complex, the bridge between the phosphorus
atoms may be a tetramethylene (i.e., butyl) group and further teaches that the
bisphosphine derivative used as a starting material to produce the complex
“may be produced by a known method.” FF2, FF3. Similarly, Hill teaches
antitumor bisphosphine derivatives, as well as transition metal phosphine
complexes comprising such derivatives, that have an alkanediyl bridge
connecting the two phosphorus atoms of the bisphosphine derivative, and
provides examples of these compounds wherein the alkanediyl bridge is a
butyl bridge. FF7, FF8, FF10. Hill further teaches that its compounds “can
be prepared by methods available to one skilled in the art.” FF9.
Appellant points to a statement in Kodama that “minute structural
differences result in big differences in anticancer activity.” Reply Br. 2.
While we acknowledge Kodama’s general teaching that “it is known that the
anticancer activity and anticancer spectra of compounds depend significantly
on chemical structures and that minute structural differences result in big
differences in these properties” in its section entitled “Problems to be Solved
by the Invention,” we are not persuaded that this statement would have
dissuaded a skilled artisan from producing the compound of claim 7, in light
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of Kodama’s specific teachings discussed above and its teaching that its
invention is a means to solve the problem described. Kodama 1:56–62.
Appellant contends that the Examiner’s rejection is based on improper
hindsight, improperly relied on inherency with respect to the limitation
regarding palladium binding, and did not take due account of the unexpected
results presented in the Specification. Reply Br. 3–4.
We are not persuaded. While “[a]ny judgment on obviousness is in a
sense necessarily a reconstruction based upon hindsight reasoning,” such
reconstruction is proper “so long as it takes into account only knowledge
which was within the level of ordinary skill at the time the claimed invention
was made and does not include knowledge gleaned only from applicant’s
disclosure.” In re McLaughlin, 443 F.2d 1392, 1395 (CCPA 1971). In this
case, as discussed above, the Examiner’s rejection is properly based on the
teachings of the prior art.
Neither are we persuaded that the Examiner’s reliance on inherency is
improperly speculative. Reply Br. 3–4. The Examiner has shown that the
cited prior art renders obvious a compound identical to that recited in claim
7. The properties of identical compounds are inherently the same in the
absence of proof to the contrary. See, e.g., In re Donohue, 766 F.2d 531,
534 (Fed. Cir. 1985) (explaining that, “where . . . the [compounds] of [the
cited prior art] are identical to the claimed invention, the properties of [the
prior art] compounds are inherently the same as those of the claimed
invention in the absence of proof to the contrary”).
We are further unpersuaded by Appellant’s conclusory argument that
“[t]here is criticality shown for all the elements required by formula (1)
appearing in the claims” and that a prima facie case of obviousness has not
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been established, “especially when the unexpected results presented in the
specification are considered.” Reply Br. 3. As an initial matter, Appellant
did not raise arguments regarding unexpected results in the Appeal Brief.
Neither has Appellant explained why these arguments could not have been
raised earlier. Thus, arguments regarding unexpected results are waived.
See Ex parte Nakashima, 93 USPQ2d 1834 (BPAI 2010) (informative).
Moreover, “it is well settled that unexpected results must be
established by factual evidence. ‘Mere argument or conclusory statements
in the specification does not suffice.’” In re Geisler, 116 F.3d 1465, 1470
(Fed. Cir. 1997) (quoting In re De Blauwe, 736 F.2d 699, 705 (Fed. Cir.
1984)). Appellant fails to point us to specific evidence in the Specification
that demonstrates the alleged unexpected results exhibited by the claimed
invention.6
Finally, citing Section VI of MPEP § 2144.09, Appellant contends
that Kodama’s phosphine ligand is “solely useful as an intermediate” for

6 We note that, although not cited in the Reply Brief, the Specification does
provide an experiment comparing “inventive ligand 1” (bis(2-pyridyl-tert-
butylphosphine)butane) and “comparative ligand 2”
(bis(diadamantylphosphino)butane), wherein the Specification concludes
that “[the] experiment shows that the inventive ligand 1 forms a catalytically
active palladium complex which catalyses the alkoxycarbonylation of di-n-
butene” whereas “[t]he structurally similar ligand 2 . . . is unsuitable for
catalysing alkoxycarbonylation.” Spec. 16:5–26:9. To the extent Appellant
is referencing this comparison in its arguments regarding unexpected results,
we note that “when unexpected results are used as evidence of
nonobviousness, the results must be shown to be unexpected compared with
the closest prior art.” In re Baxter Travenol Labs., 952 F.2d 388, 392 (Fed.
Cir. 1991). The experiment in the Specification does not compare the
claimed compound to, for instance, the compound of Kodama’s Example 1.
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preparing the final anti-cancer agent; thus, “no activity [is] expected to be
‘maintained’ for the . . . homologue[s].” Reply Br. 3.
We are not persuaded. Section VI of MPEP § 2144.09 cites In re
Lalu, 747 F.2d 703 (Fed. Cir. 1984), for the proposition that “if the prior art
merely discloses compounds as intermediates in the production of a final
product,” a skilled artisan “would not ordinarily stop the reference synthesis
and investigate the intermediate compounds with an expectation of arriving
at claimed compounds which have different uses.”
In In re Lalu, the invention relates to certain perfluoroalkyl sulfonyl
chlorides and bromides useful as “corrosion inhibiting agents, surface active
agents, and leveling agents.” 747 F.2d at 703. The prior art teaches certain
1,1-dihydroperfluoroalkyl sulfonic acids containing from two to five carbon
atoms, which are useful as high energy fuels and in reactions such as base
neutralization, alkylation catalysis, and metal cleaning. Id. at 704. The prior
art also teaches a method of preparing the 1,1-dihydroperfluoroalkyl sulfonic
acids from the hydrolysis of 1,1-dihydroperfluoroalkyl sulfonyl chlorides,
which are preferably isolated before hydrolysis in order to obtain a purer
sulfonic acid product. Id. The rejection is based on the structural similarity
between the reference sulfonyl chloride compounds used to make the
sulfonic acids and the claimed compounds. Id.
The Lalu Court held that the prior art reference “does not teach the
isolation and investigation of the intermediate sulfonyl chlorides, but rather
discloses, as an optional step, the isolation and purification of the
intermediate to obtain a purer sulfonic acid end product.” In re Lalu, 747
F.2d at 707. The court further held that this is “not motivation sufficient to
support the structural obviousness rejection,” because
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[t]he mere fact that [prior art] sulfonyl chlorides can be used as
intermediates in the production of the corresponding sulfonic
acids does not provide adequate motivation for one of ordinary
skill in the art to stop the [prior art] synthesis and investigate
the intermediate sulfonyl chlorides with an expectation of
arriving at appellants’ claimed sulfonyl halides for use as
corrosion inhibiting agents, surface active agents, or leveling
agents.
Id.
In this case, however, the bisphosphines of Kodama and Hill are not
mere intermediates that no longer exist once the final prior art product is
formed. Rather, the bisphosphines are ligands that complex with the metal
ions and therefore remain part of the anticancer complex. In contrast, the
intermediate in Lalu was chemically hydrolyzed to form a different
compound. In Kodama and Hill, the bisphosphines are not structurally
changed as in Lalu, but rather complex with the metal by electron donation
(Ans. 10). The biphosphines are not merely serving as chemical
intermediates, but rather are the functional and active moiety complexed to
the metal.
Thus, the bisphosphines in this case are known to have an anticancer
utility apart from their usefulness as a starting material or an “intermediate”
in a reaction. Moreover, unlike Lalu where the prior art reference provides
no motivation to “investigate the intermediate sulfonyl chlorides with an
expectation of arriving at appellants’ claimed sulfonyl halides,” in this case
Kodama and Hill explicitly provide a reason why a skilled artisan would
replace the ethyl bridge with a butyl bridge in the bisphosphines, with a
reasonable expectation of success at arriving the claimed compound,
because Kodama teaches that the alkyl bridge between the phosphorus atoms
of its bisphosphines may be a butyl bridge, and Hill similarly provides
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examples of transition metal phosphine complexes comprising
bisphosphines having a butyl bridge between its phosphorus atoms. FF1,
FF2, FF7–FF10.
B. Improper Markush grouping rejection (claim 1)
1. Issue
The Examiner finds that the members of the Markush group recited in
claim 1 “do not share a substantial [structural] feature and/or a common use
that flows from the substantial structural feature,” because “[t]he only non-
variable atoms in Formula I are the butane chain and two phosphorus
atoms,” and “[t]his structure is insubstantial to the disclosure of the
compounds in the specification.” Ans. 7 (emphasis omitted).
More particularly, the Examiner finds that the Specification discloses
only a single example compound (i.e., the compound of claim 7), whereas
claim 1 is “so expansive that a common utility cannot be expected” of the
encompassed compounds, particularly because it is known in the art that
catalysis is an unpredictable, that heteroaryl groups have different properties
depending on it heteroatom(s), and that “changing substituents on
phosphorus ligands,” which may result for instance in changes in steric
effects, “can cause marked changes in the behavior of the free ligands and of
their transition metal complexes.” Ans. 8–10.
Appellant disputes that claim 1 is drafted in improper Markush group
format.
The issue with respect to this rejection is whether a preponderance of
the evidence of record supports the Examiner’s rejection of claim 1 as
containing an improper Markush grouping of alternatives.
2. Analysis
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“A ‘Markush’ claim recites a list of alternatively useable species”
regardless of format. 76 Fed. Reg. 7162, 7166 (2011) (footnote omitted).
“A Markush claim contains an ‘improper Markush grouping’ if: (1) The
species of the Markush group do not share a ‘single structural similarity,’ or
(2) the species do not share a common use.” Id. “Members of a Markush
group share a ‘single structural similarity’ when they belong to the same
recognized physical or chemical class or to the same art-recognized class.”
Id. “Members of a Markush group share a common use when they are
disclosed in the specification or known in the art to be functionally
equivalent.” Id.
We are not persuaded that the Examiner has established a prima facie
case that claim 1 contains an improper Markush grouping. The Examiner
asserts that “[t]he only non-variable atoms in Formula I are the butane chain
and two phosphorus atoms” and that “[t]his structure is insubstantial to the
disclosure of the compounds in the specification.” Ans. 7.
However, the Specification states that the invention relates to butyl-
bridged diphosphine compound and teaches that bidentate diphosphine
compounds are typically used as ligands to modify a palladium catalyst for
alkoxycarbonylation reactions. Spec. 1:10–22. The Specification further
states that “butyl-bridged diphosphine compounds substituted by at least one
heteroaryl radical on at least one phosphorus atom” are “particularly suitable
as bidentate ligands for palladium complexes and lead to elevated yields in
the alkoxycarbonylation of ethylenically unsaturated compounds, especially
of C8 olefins.” Id. at 2:13–16. Accordingly, we are not persuaded that the
butyl-bridged diphosphine structure is “insubstantial” to the disclosure of the
compounds in the Specification.
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Furthermore, we note the structural similarity of the claimed
compounds extends beyond the butane chain and phosphorus atoms, because
claim 1 also limits the substituents R1–R4 that may be used in the claimed
compounds.
The Examiner asserts that, although claim 1 defines “R1 and R3 . . . as
heteroaryl having 6 to 10 ring atoms,” the claim nevertheless contains
improper Markush grouping because (1) this definition of R1 and R3
encompasses a large number of species whereas the Specification provides
only one example, pyridine; (2) “it is the heteroatom which imparts to a
heterocyclic its distinctive and sometimes striking properties”; and (3) “[i]t
is well known that molecular structure is correlated with physical properties
and in particular in heterocyclic chemistry the change from one ring to
another often results in dramatic changes in properties.” Ans. 8–9.
Although we acknowledge the Examiner’s point, we are not
persuaded. As the predecessor to our reviewing court has explained, “[i]t is
evident that in any Markush group, the compounds which are included will
differ from each other in certain respects” and that “[i]n determining the
propriety of the grouping, those differences must, to some extent, be
weighed against the similarities.” In re Jones, 162 F.2d 479, 481 (CCPA
1947). Moreover, “[i]n determining the propriety of a Markush grouping . . .
the compounds which are grouped must each be considered as a whole and
should not be broken down into elements or other components,” in part
because “[w]hether or not one portion of a compound is considered more
important than another depends upon the purpose for which the compound is
intended.” Id.
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In this case, even though we take the Examiner’s point that the
identity of the heteroatom may provide the heteroaryl with distinctive
properties, we are not persuaded that the Examiner has provided evidence
sufficient to show that the claimed compounds, wherein R1 and R3 are
heteroaryl having 6 to 10 ring atoms, do not have “‘a community of
chemical or physical characteristics’ which justify their inclusion in a
common group,” or that such inclusion is “repugnant to principles of
scientific classification.” In re Jones, 162 F.2d at 482.
The Examiner also asserts that “the alkyl group in the elected species
is quite bulky and appears to be essential for the catalytic activity,” whereas
claim 1 allows R2 and R4 to be any C1 to C4 alkyl. Ans. 9.
We are not persuaded for reasons similar to those discussed above
with respect to the Examiner’s reasoning regarding R1 and R3. The
Examiner cites evidence that “‘changing substituents on phosphorus ligands
can cause marked changes in the behavior of the free ligands and of their
transition metal complexes,” including in their catalytic effect with regard
to, e.g., reaction rate and product composition. Ans. 9–10. The Examiner
has not cited persuasive evidence, however, that compounds of claim 1,
wherein the R2 and R4 group are selected from -(C1-C4)-alkyl, would not
function as catalysts, or that a skilled artisan would not consider such
compounds to “belong to the same recognized physical or chemical class or
to the same art-recognized class.” See 76 Fed. Reg. at 7166.
The Examiner asserts that, despite the fact that “[c]atalysis is
generally considered unpredictable merely from the chemical nature of the
catalyst,” only a single example compound is disclosed in the Specification.
Ans. 7–8. The Examiner asserts that “[t]he claim[ is] so expansive that a
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common utility cannot be expected.” Id. at 8. The Examiner asserts that
“[b]y appellant’s own admission other compounds do not work” to catalyze
alkoxycarbonylation, including “catalysts of this formula.” Id. at 8, 9. The
Examiner further cites to Appellant’s statements in the Appeal Brief that the
prior art references do not suggest that their compounds are useful as active
catalysts and that the Specification suggests that 2-pyridyl may play a role in
the catalysis. Id. at 15.
We are not persuaded. To the extent the Examiner refers to
Appellant’s statement that “ligand 2” is “unsuitable for catalysing
alkoxycarbonylation,” we note that ligand 2 refers to
bis(diadamantylphosphino)butane, which does not appear to fall within the
scope of claim 1 because its R1–R4 are each adamantyl, which are neither
heteroaryl nor a –(C1–C4)-alkyl. Similarly, Appellant’s statements that a
particular R1/R3 group (2-pyridyl) may play a role in the catalysis, or that
prior art fails to disclose the catalytic function of similar compounds, are not
admissions that compounds of claim 1 do not share a single structural
commonality or common use. Finally, the mere facts that only a single
example is disclosed in the Specification or that the claim encompasses a
large number of species do not, by themselves, suffice to show that members
of the Markush group do not share a single structural similarity and/or
common use, which is the standard for determining whether a Markush
group is improper.
Accordingly, we reverse the Examiner’s rejection of claim 1 as
containing an improper Markush group.

CONCLUSION
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In summary:
Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1, 7 103 Kodama,
Wislicenus, Hill
1, 7
1 Improper Markush
Group

1
Overall
Outcome
1, 7

TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R.
§ 1.136(a)(1)(iv).

AFFIRMED