Apr. 8, 2004  45  US 2004/0067216 Al  *  *  *  *  *  (A)  contacting a cation exchange resin with a compound  of Formula  (I)  in an aqueous or polar organic medium  under conditions and for a time sufficient for the  compound to form a complex with the resin; and  (B) recovering the complex.  ( aS,yS,2S)-4-[1-[ 5-( 4-fluorophenyl)-2-oxazolyl]-1-meth› ylethyl ]-N-[ (3S,4S)-3,4-dihydro-3-hydroxy-2H-1-ben› zopyran-4-y 1 ]-a-( furo[2,3-c ]pyridin-2-y lmethy l)-y-hy› droxy-2-[[ (2,2,2-trifluoroethyl)amino ]carbonyl]-1- piperazinepentanamide;  ( aS,yS,2S)-4-[1-[ 5-( 4-chlorophenyl)-2-oxazolyl]-1-me› thylethyl]-N-[ (3S,4S)-3,4-dihydro-3-hydroxy-2H-1- benzopyran-4-y 1 ]-a-( furo[2,3-c ]pyridin-3-y lmethy l)-y› hydroxy-2-[[ (2,2,2-trifluoroethy l)amino ]carbonyl ]-1- piperazinepentanamide;  ( aS,yS,2S)-4-[1-[ 5-( 4-fluorophenyl)-2-oxazolyl]-1-meth› ylethyl ]-N-[ (3S,4S)-3,4-dihydro-3-hydroxy-2H-1-ben› zopyran-4-y 1 ]-a-( furo[2,3-c ]pyridin-3-y lmethy l)-y-hy› droxy-2-[[ (2,2,2-trifluoroethyl)amino ]carbonyl]-1- piperazinepentanamide;  ( aS,yS,2S)-N-[ (3S,4S)-3,4-dihydro-3-hydroxy-2H-1- benzopyran-4-y 1 ]-4-[ 1-[ 5-( 4-fluoropheny 1)-2-ox› azoly 1 ]-1-methy le thy 1 ]-a-( furo[2,3-d]pyrimidin-6-y l› methyl)-y-hydroxy-2-[[ (2,2,2-trifluoroethy l)amino]  carbonyl ]-1-piperazinepentanamide;  and pharmaceutically acceptable salts thereof.  11.  The composition according to claim 1, wherein the  complex comprises Compound  A  or a pharmaceutically  acceptable salt thereof, wherein Compound  A  is ( aR,yS,2S)- 4-[[ 5-( 5-chloro-2-pyridiny 1)-2-furany 1 ]me thy 1 ]-N-( (3S,4S)- 3,4-dihydro-3-hydroxy-2H-1-benzopyran-4-y l)-y-hydroxy› a-(phenylmethyl)-2-[[(2,2,2-trifluoroethyl)amino]  carbonyl]-1-piperazinepentanamide.  12.  The composition according to claim 1, wherein the  cation exchange resin is an acidic sulfonic acid resin or an  acidic carboxylic acid resin.  13.  The composition according to claim 1, wherein the  cation exchange resin is a strongly acidic resin.  14.  The composition according to claim 1, wherein the  cation exchange resin is an acidic sulfonic acid resin.  15.  The composition according to claim 14, wherein the  cation exchange resin is Amberlite IRP-69.  16.  The composition according to claim 15, wherein the  Amberlite IRP-69 is complexed with Compound  A  or a  pharmaceutically acceptable salt thereof, wherein Com› pound  A  is (aR,yS,2S)-4-[[5-(5-chloro-2-pyridinyl)-2-fura› nyl ]methyl]-N-((3S,4S)-3,4-dihydro-3-hydroxy-2H-1-ben› zopyran-4-yl)-y-hydroxy-a-(phenylmethyl)-2-[[(2,2,2- trifluoroethyl)amino ]carbonyl ]-1-piperazinepentanamide.  17.  The composition according to claim 1, which further  comprises a capsule containing the complex.  18. A  method of inhibiting  HIV  protease in a subject in  need thereof which comprises administering to the subject a  therapeutically effective amount of the composition accord› ing to claim  1.  19. A  method of preventing or treating infection by  HIV  in a subject in need thereof which comprises administering  to the subject a therapeutically effective amount of the  composition according to claim  1.  20. A  method of treating or delaying the onset of  AIDS  in  a subject in need thereof which comprises administering to  the subject a therapeutically effective amount of the com› position according to claim  1.  21. A  process for preparing the composition according to  claim 1 which comprises:  22.  The process according to claim 21, wherein the cation  exchange resin is an acidic sulfonic acid resin.  23.  The composition prepared by the process of claim 22.  24.  The complex formed by contacting a cation exchange  resin with a compound of Formula (I) as defined in claim  1. 