Appeal 2007-0711
Reexamination 90/006,706
ratios); and (2) effecting separation by selecting and using one of the mobile
phase compositions compared which affords a retention capacity (k’) for a
chiral isomer to be separated such that 0.1<k’<1.0.
We are well aware that the Examiner relied upon the additional
teachings of Ching and Snyder to help make its case for the unpatentability
of Appellants’ process claims under 35 U.S.C. § 103. However, Appellants
have argued, and we find little evidence to dispute its argument, that the
teachings of Ching and Snyder reasonably would have led persons having
ordinary skill in the art to understand that achiral isomers classically are
separated from mixtures thereof using a mobile phase solvent composition
having a retention capacity (k’) for at least one of the isomers in a mixture of
greater than 1. Nevertheless, we find that the teachings of Ching and Snyder
neither buttress nor undermine the evidence in Negawa and Pirkle against
the patentability of the invention Appellants claim.
Negawa and Pirkle are specifically directed to processes for
separating chiral (optically active) isomers using a mobile phase solvent.
Negawa suggests that prior knowledge relating to the use of simulated
moving bed systems for separating achiral isomers does not necessarily
apply, and may not apply at all, for the separation of optically active
isomers. Negawa states (Negawa, col. 3, ll. 20-27):
The simulated moving bed system per se is well known as
described in, for example, Japanese Patent Publication-B No.
15681/1967. However, the simulated moving bed system has
heretofore been employed only for the production of fructose,
separation of maltose and recovery of co-enzymes and no process has
been described at all for separating optical isomers by this system.
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