Appeal 2007-0313
Application 10/414,447
6. OBVIOUSNESS
Claims 1-12, 30-32, 36-39, and 48 stand rejected under 35 U.S.C.
§ 103 as obvious in view of Bühlmayer and Cheronis. The Examiner relies
on Bühlmayer’s disclosure of crystalline valsartan and cites Cheronis as
teaching that the “skill of art for preparing a compound in a crystalline form
by choosing proper solvent (i.e., acetone, ethyl acetate, etc.), temperature,
and concentration has been taught” (Answer 12-13). The Examiner
concludes that the “employment of a conventional obvious modification of a
known process to obtain a pure form (i.e., crystalline or amorphous form) is
considered prima facie obvious in the absence of unexpected results” (id. at
13).
Appellants argue that the cases cited by the Examiner as supporting
the obviousness rejection are distinguishable or are no longer good law, and
that Bühlmayer does not “provide a reasonable expectation of success for
making a different polymorph, let alone the two specific polymorphs that are
being claimed by appellants” (Br. 8-10).
We agree with Appellants that the cited references do not support a
prima facie case of obviousness. Bühlmayer is discussed above. As we
understand it, the Examiner relies on Cheronis for its teaching of
recrystallization methods, and concludes that it would have been obvious to
those skilled in the art to recrystallize Bühlmayer’s valsartan and thereby
obtain the claimed crystalline forms.
We do not agree with the Examiner’s conclusion. Cheronis shows
that recrystallization was a well-known purification technique in organic
chemistry. Thus, those skilled in the art would have considered it obvious to
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