Process for the preparation of drospirenone

Abstract

A process is described for the preparation of drospirenone, a synthetic steroid with progestogenic, antimineralocorticoid and antiandrogenic activity, useful for preparing pharmaceutical compositions with contraceptive action; comprising the oxidation of 17α-(3-hydroxypropyl)-6β,7β,15β,16β-dimethylene-5β-androstane-3β,5,17β-triol.

1 .- 25 . (canceled) 
     
     
         26 . Drospirenone having purity higher than 96.5%, obtained by oxidation of 17α-(3-hydroxypropyl)-6β,7β,15β,16β-dimethylene-5β-androstane-3β,5,17β-triol compound of formula (VIII) as defined in claim  1  with a suitable oxidising agent in an organic solvent, in the presence of a catalytic amount of 2,2,6,6-tetramethylpiperidine-1-oxyl radical or a derivative thereof, and said oxidation being followed by the addition of a protic acid, directly into the same container in which the oxidation took place, to obtain the drospirenone of formula (I). 
       
         
           
           
               
               
           
         
       
     
     
         27 . Drospirenone having purity higher than 99.5%, obtained by purification of the product obtained by the process as defined in  claim 26 , by gel filtration and filtrate crystallisation from organic solvent, without subjecting the product to any chromatographic procedure. 
     
     
         28 . A pharmaceutical composition comprising drospirenone as defined in  claim 26  as active principle, and a carrier. 
     
     
         29 . A pharmaceutical composition comprising drospirenone as defined in  claim 27  as active principle, and a carrier.