Appeal 2007-1817
Application 10/045,510
methyl]cyclohexanol (a starting material for the preparation of venlafaxine),
Jerussi extracts the product with ethyl acetate and then further purifies it by
triturating and washing it with hexane. (Jerussi 22: 25-26.)
Given Jerussi’s teachings, one skilled in the art would have known
pure venlafaxine was colorless and would have been motivated to purify the
“pale yellow solid” (not a “gum” as Appellants contend, because the gum is
described as becoming a pale yellow solid) in order to obtain greater purity.
In any case, Appellants claims are not limited to the racemate. Thus,
Jerussi’s teachings regarding 99.95% pure colorless (+)-venlafaxine are just
as relevant as those relating to the racemate. Further, the salts of venlafaxine
are also colorless (Jerussi 24: 15, 24, 37), confirming pure venlafaxine is not
a colored compound.
As previously noted, Appellants do not describe how they determine
color or define the term “crystalline” with respect to the claims before us.
For that reason, we find the differences between the prior art and the claimed
invention are at most the color and degree of crystallinity of Jerussi’s
racemic venlafaxine and Appellants’ claimed white crystals.4
We acknowledge Appellants' argument that color is not necessarily
indicative of a compound's purity and that a compound's color may reflect a
polymorphic form of the compound. However, to the extent Appellants
suggest a form of venlafaxine is colored, we find otherwise. Based on the
evidence of record, we find the skilled artisan would have known
substantially pure venlafaxine is colorless. Thus, the skilled artisan would
4 With respect to Jerussi’s (+)-venlafaxine, the only arguable difference is
the degree of crystallinity, and, given that it’s 99.95% pure and colorless, we
find it is more likely than not crystalline.
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