Appeal No. 2000-0599
Application No. 08/357,363
V. Obviousness
Claims 30 and 48 stand rejected under 35 U.S.C. ' 103 as unpatentable over
Pandit, Grose, Stewart, Greene and Verheyden.
As explained by appellants, APandit discloses an impure preparation of about 45-
50% PCV and 50-55% monobenzyl and dibenzyl esters@ which Awas merely a chemical
intermediate in the synthesis of a desired end product,@ i.e., Anucleotide analogues or
novel nucleic acid models . . . constitut[ing] a new class of potential anti-mitotic or anti-
viral agents.@ Reply Brief, page 5. Appellants emphasize that APandit presumes that it
is the nucleotide produced by phosphorylation of the nucleoside . . . rather than the
nucleoside itself, that has antiviral activity.@ Id.
The examiner concedes these points, but nevertheless argues essentially that
one skilled in the art would have had both the motivation and the means to purify
Pandit=s intermediate preparation, inasmuch as Pandit=s intermediate was known to
contain monobenzyl and dibenzyl esters which would not be phosphorylated in
subsequent steps, and A[o]ne skilled in the art of synthetic organic chemistry will
naturally seek to maximize yields, and . . . to obtain the cleanest material possible@
(Answer, 24th page) and the other secondary references (Stewart, Greene and
Verheyden) Aestablish that there was known in the art a wide assortment of procedures
for debenzylation of benzyl ethers@ (Id., 26th page).
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