Ex Parte Eliu et al

Board of Patent Appeals and Interferences

Apr 23, 2007

10399312 (B.P.A.I. Apr. 23, 2007)

The opinion in support of the decision being entered today was not written
for publication and is not binding precedent of the Board.

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte PAUL VICTOR ELIU and JULIA HAUSER
__________

Appeal 2007-0549
Application 10/399,312
Technology Center 1600
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Decided: April 23, 2007
__________

Before DONALD E. ADAMS, DEMETRA J. MILLS, and
ERIC GRIMES, Administrative Patent Judges.

GRIMES, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 involving claims to processes
of preparing bis-benzazolyl compounds. The Examiner has rejected the
claims as obvious. We have jurisdiction under 35 U.S.C. § 6(b). We affirm.
BACKGROUND
Bis-benzazolyl compounds “are useful as optical whitening agents for
natural and synthetic materials” (Specification 1). These compounds can be
made by “processes in which dicarboxylic acids or their derivatives are
Appeal 2007-0549
Application 10/399,312

reacted with bifunctional aromatic compounds to form the heterocyclic rings
in a single reaction step” (id.).
The Specification discloses, however, that the prior art processes “are
disadvantageous since they demand extremely high reaction temperatures,
resulting in the formation of impurities which are difficult to remove from
the final products and, as a consequence, loss of product yields” (id.). Also,
“such high-boiling solvents are . . . difficult to remove from the reaction
products and may further result in crust-formation inside reaction vessels,
thus impeding work-up of the final products. Additionally, employment of
chlorinated aromatic solvents . . . is undesirable for ecological reasons” (id.).
The Specification discloses processes in which bis-benzazolyl
compounds are prepared by reacting dicarboxylic acids or their esters with
bifunctional aromatic compounds, such as aminophenol, in the presence of
an acid catalyst, using N-methylpyrrolidone or N,N-dimethylacetamide as
the solvent (id. at 2).
DISCUSSION
1. CLAIMS
Claims 1-11 are pending and on appeal. The claims have been argued
together (Br. 4),1 and therefore stand or fall together. 37 C.F.R.
§ 41.37(c)(1)(vii). We will focus on claim 1, the broadest claim on appeal,
which reads as follows:
1. A process for the preparation of a compound of the
formula

1 Supplemental Appeal Brief received June 22, 2006.
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Application 10/399,312

wherein Y represents -O-, -S- or -N(R2)-,
R2 being hydrogen, C1-C10alkyl or aralkyl;
Z represents a 2,5-furanyl, 2,5-thiophenyl, 4,4'-stilbenyl or a
1,2-ethylenyl residue and
R1 represents hydrogen, halogen, C1-C10alkyl, C1-C10alkoxyl,
cyano, COOM or SO3M, M being hydrogen or an alkaline or
alkaline earth metal,

which comprises reacting a compound of the formula

with a dicarboxylic acid of the formula

or an ester thereof,
Y, Z and R1 being as previously defined,
in N-methylpyrrolidone or N,N-dimethylacetamide, in the
presence of an acidic catalyst and, optionally, in the presence of
a secondary solvent capable of removing water from the
reaction mixture.

Thus, claim 1 is directed to a process of producing a bis-benzazolyl
compound of formula (1) by reacting a compound of formula (2) with a
dicarboxylic acid of formula (3) and an acidic catalyst, in either N-
methylpyrrolidone or N,N-dimethylacetamide.
2. PRIOR ART
The Examiner relies on the following references:
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Application 10/399,312

Duennenberger (Duennenberger ‘545) US 2,842,545 Jul. 8, 1958
Duennenberger (Duennenberger ‘564) US 2,995,564 Aug. 8, 1961
Liechti US 3,407,196 Oct. 22, 1968
Erckel US 4,282,355 Aug. 4, 1981
Schreiber US 4,327,209 Apr. 27, 1982

Goda EP 0 719 774 A1 Jul. 3, 1996
Maeder (as translated) CH 439 292 Dec. 15, 1967

2. OBVIOUSNESS
Claims 1-11 stand rejected under 35 U.S.C. § 103 as obvious over
Duennenberger ‘545, Schreiber, Maeder, Liechti, Goda, and Duennenberger
‘564, “each taken alone or in combination of each other, and each in view
of” Erckel (Answer 4-5).2
The Examiner cites each of the first six references as teaching
processes of preparing compounds of formula (1) “by reacting an amino-
benzene compound (e.g., 2-aminophenol) with a dicarboxylic acid (e.g.,
stilbene-4,4'-dicarboxylic acid or thiophene-2,5-dicarboxylic acid) in the
presence of an acidic catalyst (e.g., boric acid)” (Answer 5-6).
The Examiner concedes that “the prior art does not teach
Appellant[s’] N-methylpyrrolidone or N,N-dimethylacetamide. The prior art
teaches N,N-dimethylformamide instead in the reaction[;] see, for example,
Liechti et al. (column 2, lines 47-49)” (id. at 6-7).
To meet this limitation, the Examiner cites Erckel as “teach[ing] a
process of making bis-benzazolyl compounds by reacting an amino-benzene
compound (e.g., 2-aminophenol) with a carboxylic acid in the presence of an
acidic catalyst (e.g., boric acid)” (id. at 7). The Examiner points out that

2 Examiner’s Answer mailed August 24, 2006.
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“Erckel et al. further teach the interchangeability of suitable aprotic solvents
(such as N,N-dimethylformamide and N-methylpyrrolidone) in a process of
making bis-benzazolyl compounds (column 2, lines 52-55)” (id.).
The Examiner concludes that one of ordinary skill would have been
motivated by Erckel’s disclosure of the interchangeability of aprotic solvents
to substitute Erckel’s N-methylpyrrolidone for the solvents used to prepare
bis-benzazolyl compounds in the remaining references (see id. at 7-8).
The Examiner may establish a prima facie case of obviousness based
on multiple references “only by showing some objective teaching in the
prior art or that knowledge generally available to one of ordinary skill in the
art would lead that individual to combine the relevant teachings of the
references.” In re Fine, 837 F.2d 1071, 1074, 5 USPQ2d 1596, 1598 (Fed.
Cir. 1988).
However, an “[e]xpress suggestion to substitute one equivalent for
another need not be present to render such substitution obvious.” In re Fout,
675 F.2d 297, 301, 213 USPQ 532, 536 (CCPA 1982); see also, In re
Mayne, 104 F.3d 1339, 1340, 41 USPQ2d 1451, 1452 (Fed. Cir. 1997)
(rejection for obviousness affirmed “[b]ecause the applicants merely
substituted one element known in the art for a known equivalent”).
We agree with the Examiner that one of ordinary skill preparing
bis-benzazolyl compounds according to the teachings of Liechti would have
considered the N-methylpyrrolidone disclosed by Erckel to be an equivalent
solvent to Liechti’s dimethyl formamide.
Liechti describes the preparation of bis-benzoxazolyl-stilbene
compounds encompassed by formula (1) of claim 1 (Liechti, col. 1, l. 15,
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through col. 2, l. 8). The compounds can be prepared by reacting
aminophenols with stilbene-4,4'-dicarboxylic acid or a derivative (e.g., an
ester or acid halide) (id. at col. 2, ll. 9-37). Liechti therefore uses reactants
encompassed by claim 1. Liechti discloses that suitable solvents are “high-
boiling, polar, organic solvents such, for example, as dimethyl formamide”
(id. at col. 2, ll. 47-49).
Like Liechti, Erckel describes the preparation of bis-benzoxazolyl-
stilbene compounds (Erckel, col. 1, l. 54, through col. 3, l. 6). Erckel’s
process includes the step of reacting an aminophenol with the acid chloride
of a benzoxazolyl-stilbene-carboxylic acid (id. at col. 2, ll. 33-51). Suitable
solvents are said to be “N,N-dialkyl-carboxylic acid amides, for example
dimethyl formamide, N-methylpyrrolidone, or hexamethyl-phosphoric acid
trisamide, preferably, however, N-methylpyrrolidone” (id. at col. 2, ll. 52-55
(emphasis added)).
Thus, as Appellants argue (Br. 6), Erckel discloses the equivalence of
N-methylpyrrolidone and dimethyl formamide in processes in which the bis-
benzoxazolyl compound is made by reacting the aminophenol with a
monocarboxylic acid chloride, while claim 1 recites a reaction involving the
dicarboxylic acid.
However, Liechti additionally states that the aminophenol may be
reacted with either “stilbene-4,4'-dicarboxylic acid or . . . a functional
derivative . . . especially . . . an acid halide such as the acid chloride . . .”
(Liechti, col. 2, ll. 8-16 (emphasis added)). Thus, based on Liechti’s
teachings, one of ordinary skill would have recognized that the same
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solvents can be used in preparing bis-benzoxazolyl-stilbene compounds
from either dicarboxylic acids or their acid chloride derivatives.
Because Erckel discloses that N-methylpyrrolidone and dimethyl
formamide can be used equivalently in preparing bis-benzoxazolyl-stilbenes
from acid chloride intermediates, and because Liechti teaches that the same
solvents can be used to prepare the compounds from dicarboxylic acids or
their acid chlorides, we agree with the Examiner that it would have been
obvious to substitute Erckel’s N-methylpyrrolidone for Liechti’s dimethyl
formamide.
Appellants argue that Liechti does not provide a working example
using dimethyl formamide in the preparation of bis-benzoxazolyl-stilbene
compounds, and instead provides a “very generic and broad” list of solvents
suitable in the described processes (Br. 5-6). Appellants point out that
Liechti’s working examples of ring formation reactions use either
dichlorobenzene or xylene in the condensation reaction, followed by
cyclization in phthalic acid dibutyl ester (id. at 6). Thus, “[a]s
dimethylformamide is only very generically disclosed in Liechti, Appellants
assert that one skilled in the art cannot arrive at the present invention from
the combination of Liechti and Erckel” (id.).
We agree with Appellants that Liechti does not appear to use dimethyl
formamide in working examples of the reactions of the type recited in claim
1. However, it is well settled that, “in a section 103 inquiry, ‘the fact that a
specific [embodiment] is taught to be preferred is not controlling, since all
disclosures of the prior art, including unpreferred embodiments, must be
considered.’” Merck & Co. v. Biocraft Labs. Inc., 874 F.2d 804, 807, 10
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USPQ2d 1843, 1846 (Fed. Cir. 1989) (quoting In re Lamberti, 545 F.2d 747,
750, 192 USPQ 278, 280 (CCPA 1976).) Thus, “[a]ll the disclosures in a
reference must be evaluated, including nonpreferred embodiments, and a
reference is not limited to the disclosure of specific working examples.” In
re Mills, 470 F.2d 649, 651, 176 USPQ 196, 198 (CCPA 1972) (citations
omitted).
Even though Liechti’s most relevant working examples do not use
dimethyl formamide, the reference expressly discloses that, in processes of
producing bis-benzoxazolyl-stilbene compounds from either dicarboxylic
acids or their corresponding chlorides, “[t]here may also be used additionally
high-boiling, polar, organic solvents such, for example, as dimethyl
formamide . . . .” (Liechti, col. 2, ll. 47-49.) We agree with the Examiner that
this teaching, combined with Erckel’s disclosure that N-methylpyrrolidone or
dimethyl formamide can be used in producing such compounds from acid
chlorides, would have made it obvious to use N-methylpyrrolidone as a
solvent when preparing bis-benzoxazolyl-stilbenes from stilbene dicarboxylic
acids.
Appellants further argue that the appealed claims require the use of
dicarboxylic acids or their esters as reactants, while “the working Examples
of Liechti teach the use of acid chlorides, as does Erckel. One skilled in the
art then would conclude from this combination that it is necessary to first
convert the diacid to a diacid chloride in order to perform the reaction.”
(Br. 6.)
We are not persuaded by this argument. As noted supra, “a reference
is not limited to the disclosure of specific working examples.” In re Mills,
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470 F.2d at 651, 176 USPQ at 198. Liechti states that, to prepare
bis-benzoxazolyl-stilbene compounds, an aminophenol may be reacted with
“stilbene-4,4'-dicarboxylic acid or . . . a functional derivative . . . especially
an ester such as a diethyl ester or an acid halide such as the acid chloride”
(Liechti, col. 2, ll. 8-16 (emphasis added)). Based on Liechti’s statements,
we conclude that one of ordinary skill would have considered the
dicarboxylic acids and the acid chloride forms to be alternative reactants.
Appellants further argue that, rather than preparing the compounds
from dicarboxylic acid chloride intermediates, Erckel prepares the
compounds only from mono acid chloride precursors which have one
previously formed oxazolyl group (Br. 6). Appellants argue that “[t]hose
skilled in the art understand that compounds with mono acid moieties are not
necessarily anal[o]gous to compounds with di acid moi[e]ties, and thus,
would not be motivated to modify the teachings of the primary references
with the disclosure of Erckel” (id.).
We are not persuaded by Appellants’ argument. The reactants in both
Erckel’s and Liechti’s syntheses contain the same reactive groups:
carboxylic acid chlorides linked to stilbene moieties, and o-aminophenols.
Appellants do not explain why one of ordinary skill would have
considered Erckel’s synthesis non-analogous to Liechti’s, despite the
presence of the same reactive groups. In our view, because the reactants in
the references have the same reactive groups, and ultimately result in the
same final compounds, one of ordinary skill in the art would have
considered Erckel’s and Liechti’s synthesis schemes sufficiently analogous
that the same solvents could be used interchangeably.
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Finally, Appellants argue that “the success of the present invention as
demonstrated in the working Examples could not have been predicted by the
combination of the primary references with Erckel” (Br. 7).
We do not find this argument persuasive. As discussed supra, Liechti
discloses that the same solvents, among them dimethyl formamide, can be
used to prepare bis-benzoxazolyl-stilbenes from either dicarboxylic acids or
their acid chlorides (see Liechti, col. 2, ll. 8-49). Erckel discloses that
dimethyl formamide or N-methylpyrrolidone can be used as a solvent when
preparing bis-benzoxazolyl-stilbenes from acid chlorides (Erckel, col. 2, ll.
52-55). Based on these teachings, we agree with the Examiner that one of
ordinary skill would have had a reasonable expectation of success when
substituting Erckel’s N-methylpyrrolidone for Liechti’s dimethyl
formamide.
If Appellants are relying on unexpected results to overcome the prima
facie case of obviousness, 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, 21 USPQ2d 1281, 1285 (Fed. Cir. 1991). Moreover, “[i]t 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 De Blauwe, 736 F.2d 699, 705, 222 USPQ 191, 196 (Fed.
Cir. 1984).
Appellants do not directly compare their process to the prior art
processes. Nor do Appellants provide any specific factual basis on which to
conclude that the working Examples produce unexpected results. Appellants
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therefore have not met their burden in establishing that the claimed process
yields unexpected results.
SUMMARY
Because Liechti and Erckel suggest the use of N-methylpyrrolidone as
the solvent in processes of preparing compounds of formula (1) from
reactants of formulas (2) and (3), we affirm the Examiner’s rejection of
claim 1 under 35 U.S.C. § 103(a). Claims 2-11 fall with claim 1.

No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).

AFFIRMED

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