Ex parte Chen

Board of Patent Appeals and Interferences

Apr 21, 2000

07851810 (B.P.A.I. Apr. 21, 2000)

-1-
THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered
today (1) was not written for publication in a law
journal and (2) is not binding precedent of the Board.
Paper No. 28
UNITED STATES PATENT AND TRADEMARK OFFICE
________________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
________________
Ex parte TEH-KUEI CHEN
________________
Appeal No. 1996-3017
Application No. 07/851,810
________________
HEARD: March 23, 2000
________________
Before KIMLIN, JOHN D. SMITH and OWENS, Administrative Patent
Judges.
KIMLIN, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal from the final rejection of claims 2-
10, 12, 13 and 17-20. Appellant has withdrawn the appeal of
claims 1, 11, 15 and 16, the other claims remaining in the
present application. Claim 2 is reproduced below:
Appeal No. 1996-3017
Application No. 08/851,810
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2. A process for preparation of alkyl-pyrazine compounds
comprising heating and refluxing an aqueous medium containing
ammonium ions and at least one acyloin compound having the
general formula:
H
*
R - C - C - R 1 2
* 5
OH O
wherein R and R are methyl groups, to obtain a reacted1 2
mixture, adding a base to the reacted mixture to adjust the pH
of liquid of the reacted mixture to an alkaline pH, separating
reacted mixture solid material from the pH-adjusted liquid,
adding water to the separated solid material to dissolve the
solid material to form a solution, allowing a product to
crystallyze [sic] from the solution, thereby forming a solid
crystalline product and a liquid phase, and then separating
the crystalline product from the liquid phase.
The examiner relies upon the following references as
evidence of obviousness:
Langdon 3,067,199 Dec. 4, 1962
Bonzom et al. (Bonzom) 3,676,442 Jul. 11, 1972
Kosuge et al. (Kosuge) Sho 52-97983 Aug. 17, 1977
(Japanese Kokai patent application)
4 Technique of Organic Chemistry 613-28, 627-28 (Arnold
Weissberger, ed., Interscience Publishers, Inc., New York
1951)
R.F. Evans et al. (Evans), "Diazabenzenes. I. Synthesis of
Some t-Butylpyrazines and Their N-Oxides," 25 Australian
Journal of Chemistry 2671-85 (1972)
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Application No. 08/851,810
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Takuya Akiyama et al. (Takuya), "A New Method of Pyrazine
Synthesis for Flavor Use," 26 Journal of Agricultural and Food
Chemistry no. 5, 1176-79 (1978)
Dennis J. Bell et al. (Bell), "Diazabenzenes. II. Synthesis,
Photolysis and Mass Spectra of Some Tetraalkylpyrazines,"
32 Australian Journal of Chemistry 1281-300 (1979)
George P. Rizzi, "Formation of Pyrazines from Acyloin
Precursors under Mild Conditions," 36 Journal of Agricultural
and Food Chemistry no. 2 (1988)
Appellant's claimed invention is directed to a process
for preparing and isolating alkyl-pyrazines, e.g., tetra-
alkyl-pyrazines. The process entails heating and refluxing an
aqueous solution comprising ammonium ions and an acyloin
compound of the recited formula, adding a base to the reacted
mixture to adjust the mixture to an alkaline pH, adding water
to dissolve a solid material that is separated from the
reacted mixture, and allowing the product to crystallize from
the solution. The process defined by the embodiment of claim
6 involves heating, refluxing and subliming an aqueous medium
containing ammonium ions and the acyloin compound, and
collecting the sublimed product on a cooled collection
surface.
Appellant submits at page 7 of the principal brief that
separate arguments are presented for claims 2, 5 and 6.
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Accordingly, appealed claims 3, 4, 7-10, 12, 13 and 17-20
stand or fall together with the independent claim upon which
they depend.
Appealed claims 2-5, 12, 17 and 18 stand rejected under
35 U.S.C. § 103 as being unpatentable over Kosuge, Rizzi, Bell
and Langdon in view of Bonzom and Akiyama. Claims 6-10, 13,
19 and 20 stand rejected under 35 U.S.C. § 103 as being
unpatentable over Kosuge, Rizzi, Bell and Langdon in view of
Evans, Weissberger and Akiyama.
We have thoroughly reviewed each of appellant's arguments
for patentability. However, inasmuch as we find that the
examiner's legal conclusion of obviousness is supported by the
factual findings made by the examiner, we will sustain the
examiner's rejections for essentially those reasons expressed
in the Answer. We add the following primarily for emphasis.
We consider first the examiner's rejection of claims 2-5,
12, 17 and 18. There is no dispute that Kosuge, Rizzi, Bell
and Langdon, the primary references, disclose processes for
preparing appellant's product, an alkyl-pyrazine, by reacting
appellant's reactants in an aqueous medium. The primary
references do not disclose isolating the product from the
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reaction mixture by the presently claimed crystallization
technique. However, as explained by the examiner, Bonzom
discloses that it was known in the art to separate appellant's
alkyl-pyrazines from an aqueous reaction medium by the claimed
steps of separation and recrystallization from water.
Accordingly, based on the collective teachings of the primary
references and Bonzom, we agree with the examiner that one of
ordinary skill in the art would have understood that the
claimed alkyl-pyrazines can be isolated by either the
extraction and distillation techniques disclosed by the
primary references or the recrystallization method disclosed
by Bonzom.
The principal argument advanced by appellant is that
Bonzom utilizes different reactants in preparing alkyl-
pyrazines, namely, acetylene compounds and ammonium
derivatives, and, therefore, "does not disclose, much less
suggest, that his isolation procedure would be viable in any
other reaction system" (page 18 of principal brief). However,
insofar as the reaction schemes of the primary references and
Bonzom result in the same product, an alkyl-pyrazine, in an
aqueous medium, we agree with the examiner that one of
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ordinary skill in the art would have had a reasonable
expectation of successfully isolating the product alkyl-
pyrazine from the aqueous medium utilizing the
recrystallization method disclosed by Bonzom. Appellant has
not apprised us of any reason, and we are not aware of one,
why one of ordinary skill in the art would have been dissuaded
from applying Bonzom's recrystallization technique to an
aqueous medium comprising an alkyl-pyrazine simply because the
reactant mixture may contain amounts of an acetylene starting
reactant rather than an acyloin starting reactant. Also,
since distillation, extraction and recrystallization are all
conventional techniques used in the art to isolate compounds
from aqueous medium, we are satisfied that one of ordinary
skill in the art would have found it obvious to simply
determine which of the known techniques produce the optimum
yield without the need to resort to undue experimentation.
Compare In re Boesch,
617 F.2d 272, 276, 205 USPQ 215, 219 (CCPA 1980). We find no
flaw in the following reasoning of the examiner:
The different modes of purification would be
considered alternately and even sequentially usable
since isolation is a separate consideration for the
synthetic chemist once a product mixture is obtained
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since in most cases the mixture will be contaminated
with a variety of unidentified inorganic, organic
components and one skilled in the art of organic
synthesis would be capable of picking one over
another well-known technique to achieve their goals
- whether it be highest possible yield at the
expense of some purity or very high purity at the
expense of yield or combination of techniques for
achieving highest possible yield and
purity. [Sentence bridging pages 6 and 7 of
Answer).
Regarding appellant's argument at page 19 of the
principal brief that "Bonzom refers only to neutralization
which, it is submitted, is distinct from adjusting the pH to
an alkaline condition, as claimed in claim 2, and clearly,
Bonzom is not suggestive of adjusting the pH to a pH of at
least about 8, as affirmatively recited in claim 5," it is
well settled that where patentability is predicated upon a
change in a condition of a prior art process, such as a change
in pH, temperature, and pressure or the like, the burden is on
the applicant to establish with objective evidence that the
change is critical, i.e., it leads to a new and unexpected
result. In re Woodruff, 919 F.2d 1575, 1578, 16 USPQ2d 1934,
1936 (Fed. Cir. 1990); In re Aller, 220 F.2d 454, 456, 105
USPQ 233, 235 (CCPA 1955). In the present case, appellant has
Appeal No. 1996-3017
Application No. 08/851,810
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presented no objective evidence that adjusting the reaction
mixture to an alkaline pH produces an unexpected result.
We now turn to the examiner's rejection of claims 6-10,
13, 19 and 20 under 35 U.S.C. § 103. Independent claim 6
calls for preparing alkyl-pyrazines by "heating, refluxing and
subliming" an aqueous medium containing ammonium ions and an
acyloin compound as reactants. While the primary references
do not disclose sublimation, appellant does not dispute the
examiner's factual determination that Evans discloses the
isolation of alkyl-pyrazines by a sublimation technique.
Since Weissberger evidences that sublimation was a well-known
technique for isolating volatile compounds, in general, and
Evans evidences that it was known in the art to employ
sublimation to isolate alkyl-pyrazines, we find no error in
the examiner's conclusion that it would have been obvious for
one of ordinary skill in the art to employ such a well-known
separation technique to isolate the alkyl-pyrazines produced
by the methods of the primary references. In effect, our
analysis is much the same as that discussed above with respect
to the rejection of claim 2.
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Appellant maintains that "the sublimation operation in
Evans is far, far removed from the reaction step," i.e., "[a]
plurality of processing steps intervene" (page 20 of principal
brief). Furthermore, appellant submits that "[i]n contrast to
Evans, claims 6-10, 13, 19 and 20 recite a one-step,
simultaneous reaction and isolation" (page 20 of principal
brief). However, like the examiner, we do not find that this
argument is germane to the presently claimed subject matter.
As noted by the examiner, none of claims 6-10, 13, 19 and 20
recite the asserted one-step, simultaneous reaction and
isolation. Independent claim 6 simply specifies a process
"comprising heating, refluxing and subliming an aqueous medium
. . ." (emphasis added). It is elementary that by virtue of
the claim language "comprising," the claim is "open" to
additional steps, including any intervening steps disclosed by
Evans. Moreover, we find no error in the examiner's reasoning
that even if the appealed claims recited a simultaneous
operation, performing the reaction transformation in one step
rather than sequential steps would have been obvious to one of
ordinary skill in the art, i.e., it would have been obvious
for one of ordinary skill in the art to eliminate intervening
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steps in a sublimation sequence along with their attendant
advantages. In re Thompson, 545 F.2d 1290, 1294,
192 USPQ 275, 277 (CCPA 1976); In re Marzocchi, 456 F.2d 790,
793, 173 USPQ 228, 229-30 (CCPA 1972).
As a final point, we note that appellant bases no
argument upon objective evidence of nonobviousness, such as
unexpected results which attach to the use of the claimed
crystallization and sublimation techniques for isolating
alkyl-pyrazines
viz-à-viz the distillation and extraction techniques disclosed
by the primary references.
In conclusion, based on the foregoing and the reasons
well-stated by the examiner, the examiner's decision rejecting
the appealed claims is affirmed.
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Application No. 08/851,810
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No time period for taking any subsequent action in
connection with this appeal may be extended under
37 CFR § 1.136(a).
AFFIRMED
EDWARD C. KIMLIN )
Administrative Patent Judge )
)
)
)
)
JOHN D. SMITH ) BOARD OF PATENT
Administrative Patent Judge ) APPEALS AND
) INTERFERENCES
)
)
)
TERRY J. OWENS )
Administrative Patent Judge )
ECK:clm
Appeal No. 1996-3017
Application No. 08/851,810
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Vogt & O'Donnell
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