Patent ID: 9394334
Filing Date: 2016-07-19
CPC Classification: A61P,C07J

Claim Text:
1. Process for the preparation of drospirenone comprising the following steps: a) oxidation of the compound 17α-(3-hydroxypropyl)-6β,7β;15β,16β-dimethylene-5β-androstane-3β,5,17β-triol with an oxidizing agent in the presence of a catalytic amount of; a catalyst selected from the group consisting of the 2,2,6,6-tetramethylpiperidine-1-oxyl radical, the 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl radical, the 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl radical, the 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl radical, the 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxyl radical, the 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl radical, the 4-carboxy-2,2,6,6-tetramethylpiperidine-1-oxyl radical, the 4-cyano-2,2,6,6-tetramethylpiperidine-1-oxyl radical, and the 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl radical; b) removal of the solvent from the reaction mixture by distillation, obtaining a raw oily product containing 6β,7β;15β,16β-dimethylene-5β-hydroxy-3-oxo-17α-androstane-21,17-carbolactone; and c) addition to said raw oily product of a mixture of water and an organic base and heating of the resulting mixture at a temperature comprised between 45 and 90° C., to form drospirenone.