Appeal 2007-0711 Reexamination 90/006,706 ibuprofen’s enantiomeric mixture by SMBC using an achiral liquid mobile phase composition having a retention capacity (k’) for a chiral isomer of ibuprofen to be separated such that 0.1<k’<1.0. While Appellants and the Examiner appear to agree that Pirkle does not describe the separation of at least one chiral isomer from ibuprofen by the SMBC process, we find that Pirkle compares the chiral isomer retention capacity (k’) and the resultant degree of chromatographic chiral isomer separation (α) for several different achiral liquid mobile phase compositions in a process for separating chiral isomers from an enantiomeric mixture of ibuprofen (Pirkle, Tables 9, 16, 17, 18). Pirkle’s Tables 9, 16, 17, and 18 show that, for ibuprofen, achiral liquid mobile phase compositions having k’<1 are most effective for separating its chiral isomers. Thus, a person having ordinary skill in the art at the time, considering the data in Pirkle’s tables, reasonably would have expected to effectively separate the chiral isomers of ibuprofen using an achiral liquid mobile phase composition having a chiral isomer retention capacity (k’) value of less than one. As stated, however, neither the Examiner nor Appellants found that Pirkle disclose a process for separating chiral isomers from enantiomeric mixtures using a simulated moving bed chromatography (SMBC) process. The achiral liquid mobile phase composition employed in Pirkle’s separation process employing an achiral mobile phase composition includes a “chiral selector useful in separating underderivatized enantiomers of nonsterodial anti-inflammatory agents” (Pirkle, Abstract). Pirkle’s chiral selector “is also useful in achieving the enantiomeric separation of amines, alcohol derivatives, epoxides and sulfoxides” (Pirkle, Abstract). Nevertheless, we find that Pirkle would have taught a person having 14Page: Previous 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Next
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