A PROCESS FOR PREPARING PAROXETINE HCl WHICH LIMITS FORMATION OF PINK COLORED COMPOUNDS.

摘要

The present invention provides a process for preparing paroxetine HCl from paroxetine base which provides paroxetine HCl substantially free of pink-colored compounds or an impurity identified by an HPLC RRT of about 1.5. The processes of the present invention utilize a buffer, a molar ratio of HCl to paroxetine base of less than one, and crystallize/recrystallize in the presence of an effective amount of an anti-oxidant. A preferred way to create a buffer is by using ammonium chloride. A preferred anti-oxidant is ascorbic acid. The present invention also provides for re-crystallizing paroxetine HCl prepared by the above methods or any other methods in the presence of an effective amount of an anti-oxidant such as ascorbic acid. A preferred solvent system for recrystallization is a mixture of acetone and methanol. Processes of the present invention can combine these various features.