United  States  Patent  c19J  Felder  et  al.  [11]  4,246,164  [45]  Jan.  20,  1981  [54]  PROCESS  FOR  THE  RESOLUTION  OF  (  +  )•  AND  $_{(-}$)~6-METHOXY-a-METHYL-2-NAPH› THALENEACETIC  ACID  [75]  Inventors:  Ernst  Felder,  Riva  San  Vitale,  Switzerland;  Davide  Pitre,  Milan,  Italy;  Hans  $_{Zutter, }$Schaftbausen,  Switzerland  [73]  Assignee:  Syntex  Corporation,  Panama  [21]  Appl.  No.:  55,427  [22]  Filed:  Jul.  6,  1979  [51]  Int.  0.3  ......................  C07C  91/10;  C07C  65/24;  C07B  19/00  [52]  U.S.  a  ................................  260/501.17;  562/466;  562/401;  564/507  [58]  Field  of  Search  ......................  260/501.17,  584  R;  562/466,  401  [30]  Foreign  Application  Priority  Data  Jul.  19,  1978  [CH]  Switzerland  .........................  7777/78  [56]  References  Cited  U.S.  PATENT  DOCUMENTS  2,016,962  10/1935  Flint  et  al.  .......................  260/584  R  2,016,963  3,904,682  3,904,683  3,906,038  10/1935  9/1975  9/1975  9/1975  Flint  et  al.  ....  ...................  260/584  R  •  Fried  et  al.  ..........................  562/466  Day  et  al.  ............................  562/466  Fried  et  al.  ......................  260/501.18  OTHER  PUBLICATIONS  Greenstein  et  al.,  Chem.  of  the  Amino  Acids,  John  Wiley  &  Sons,  Inc.,  N.Y.  vol.  1,  pp.  715-728  (1961).  Primary  Examiner-Joseph  E.  Evans  Assistant  Examiner-G.  T.  Breitenstein  Attorney,  Agent,  or  Firm-Joseph  I.  Hirsch;  John  A.  Dhuey  The  subject  of  the  invention  is  a  process  for  resolving  mixtures  of  (  +  )- and  ( - )-6-methoxy-a-methyl-2-naph› thaleneacetic  acid  into  the  enantiomers  thereof,  charac› terized  in  that  N-methyl-D-glucamine  [=  1-deoxy-1- (methylamino)-D-glucitol]  is  used  as  the  resolving  agent,  so  that  $_{the }$6-methoxy-a-methyl-2-naphthalenea› cetic  acid  is  converted  into  the  corresponding  diastereo› isomeric  N-methyl-D-glucamine  salt  pair  which,  be› cause  of  very  different  solubilities,  can  be  separated  easily  and  completely  with  high  yield.  [57]  ABSTRACT  19  Claims,  No  Drawings 