Appeal No. 2004-0275
Application No. 09/09/318,186
However, Welch synthesizes its chiral stationary phase on silica, as opposed to a
polymeric resin, as claimed. Liu recites the advantages of using a polymeric
stationary phase in place of a silica phase in chiral molecule resolution. Although
Liu uses the polymer stationary phase at a later step in a chiral separation
process than in claim 60 steps (a)-(c), the disadvantages of silica, namely
nonspecific interactions caused by the presence of residual silanol groups, and
advantages associated with the use of a polymeric resin, would have been
recognized by one of ordinary skill in the art as also applicable to a step of
screening for chiral selectors as well as a step of using the selectors to separate
a mixture.
Steps (d) and (e) of claim 60 are directed toward using the library of chiral
selectors synthesized in steps (a)-(c) to separate a mixture of enantiomers. This
use, although not specifically described in Welch, is suggested at page 471,
column one, which states that the selective stationary phases are useful for large
scale preparative enantioseparation. Weingarten specifically uses a selective
library to resolve a solution, separating a racemic mixture. Thus, in our view,
Weingarten in combination with Welch and Liu, would have reasonably
suggested the claimed chiral separation method to one of ordinary skill in the art.
Where the prior art, as here, gives reason or motivation to make the
claimed invention, the burden then falls on appellants to rebut that prima facie
case. Such rebuttal or argument can consist of any other argument or
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