Appeal No. 2001-0665
Application 08/439,920
advantages compared with the closest prior art intermediate of Holton. As stated in the
Appeal Brief, pages 6 and 7, a solid precursor ($-lactam) is advantageous because solids
are more easily prepared and employed, particularly at larger scales. Solids, especially
crystalline solids, can be purified and isolated more easily, e.g., by crystallization and
filtration, and are easier to handle and more stable for storage than liquids. In this regard,
appellants invite attention to the following paragraph bridging pages 8 and 9 of the instant
specification:
Preferred $-lactams of the present invention are those compounds . . .
which are crystalline compounds, rather than liquids (oils) at ambient
conditions. Such crystalline compounds are advantageous relative to liquid
compounds as they may be more easily prepared and obtained in pure form,
particularly at larger scales, thus facilitating their subsequent use as
intermediates in the formation of sidechain-bearing taxanes such as taxol
and taxol derivatives. (Emphasis added).
According to appellants, the crystalline solid form of the $-lactam which can be a precursor
to the presently claimed intermediate is unexpected and advantageous.
Accordingly, appellants argue that their claimed intermediate possesses unexpected
advantages with respect to ease of preparation compared with the 1-ethoxyethoxy
intermediate disclosed by Holton.
Appellants also argue that the claimed intermediate (formula (VII)) has a non-
asymmetric group at the 20 position on the C-13 sidechain; that the closest prior art
intermediate of Holton has an asymmetric group at that position; and that this difference
gives rise to significant advantages possessed by the claimed intermediate (Appeal Brief,
6
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