Novel palonosetron salts and processes for preparation and purification thereof

Abstract

Provided are novel salts of 2-(1-azabicyclo-[2.2.2]oct-3-yl)-2,3,3a,4,5,6-hexahydro-1H-benz[de]isoquinolin-1-one, methods of using such salts, and processes for producing such salts.

1 . (canceled) 
     
     
         2 . A method of preparing pure palonosetron or a salt thereof, the method comprising:
 (a) dissolving or partially dissolving impure palonosetron in an organic solvent;   (b) optionally cooling the solution or partial solution of step (a) to a temperature below 20° C.;   (c) admixing an acid and the solution of step (a) or step (b) to form crystals of a pure palonosetron salt, which is different from the HCl salt, and   (d) optionally converting the pure palonosetron salt into the free base, wherein the impure palonosetron has a purity of up to 99.1% and an isomer ratio of up to 97:3 (3S),(3aS) isomer:(3S),(3aR) isomer, and the pure palonosetron or salt thereof has a purity of at least 99.5% and a (3S),(3aS):(3S),(3aR) isomer ratio of 99:1 or greater.   
     
     
         3 . The method of  claim 2 , further comprising isolating the crystals. 
     
     
         4 . The method of  claim 2 , wherein the organic solvent is selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, and mixtures thereof. 
     
     
         5 . The method of  claim 4 , wherein the organic solvent is ethanol. 
     
     
         6 . The method of  claim 2 , wherein the acid of step (c) is selected from oxalic acid, benzoic acid, maleic acid, malonic acid, fumaric acid, tartaric acid, succinic acid, citric acid, methanesulfonic acid, hydrobromic acid, phosphoric acid, and mixtures thereof. 
     
     
         7 - 21 . (canceled)