Ex Parte 5518625 et al - Page 7

                Appeal  2007-0711                                                                              
                Reexamination 90/006,706                                                                       
                      compound in order to improve the efficacy of the medicine per unit                       
                      quantity and to prevent drug-induced sufferings caused by adverse                        
                      reactions to the drug.  For the separation of such an optical isomer                     
                      mixture, . . . the chromatographic methods known at present are of a                     
                      batch type and hence cannot avoid discontinuous and unstationary                         
                      operations, which is unsuitable for the mass processing.  Further,                       
                      this chromatographic method has another defect in that since a large                     
                      amount of an eluent is necessitated and the concentration of the                         
                      intended compound in the eluate is low, much energy and                                  
                      complicated steps are necessitated for the recovery.                                     
                As its objectives, Negawa instructs (Negawa, col. 1, ll. 51-58):                               
                             An object of the present invention is to provide a novel process                  
                      which can separate optical isomers and a solvent efficiently from a                      
                      large amount of a mixture comprising the optical isomers.   Another                      
                      object of the present invention is to provide a process for efficiently                  
                      separating each of optical isomers and a solvent from a large amount                     
                      of a mixture comprising the optical isomers and also reusing the                         
                      recovered solvent.                                                                       
                To meet it objectives, Negawa teaches (Negawa, col. 1, l. 61, to col. 2, l. 14;                
                emphasis added):                                                                               
                             The invention which solves the above problem relates to a                         
                      process for recovering optical isomers and a solvent in optical                          
                      resolution by introducing a liquid containing an optical isomer                          
                      mixture and an eluent into a packed bed containing packings for                          
                      optical resolution,  having both ends connected to each other through                    
                      a fluid passage to be endless and circulating the liquids therein by                     
                      one-way flow, and simultaneously recovering a liquid containing one                      
                      optical isomer and  a liquid containing the other optical isomer which                   
                      are separated from  the packed bed, characterized by arranging an inlet                  
                      for the eluent, an outlet for a liquid (extract) containing an easily                    
                      adsorbable optical  isomer, an inlet for the liquid containing an optical                
                      isomer mixture, and an outlet for a liquid (raffinate) containing a                      
                      difficultly adsorbable optical isomer in this order in the direction of                  
                      liquid flow onto the packed bed, and recovering the solvent and                          

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