Patent ID: 9695213
Date: 2017-07-04
CPC Classifications: C07J

Claim:
1. A process for the preparation of drospirenone of the formula (I): comprising the step of: reacting 17α-(3-hydroxypropyl)-6β,7β;15β,16β-dimethylene -5β-androstane-3β,5,17β-triol of the formula (II): with oxygen, at a temperature in the range of 30° C. to 50° C., in the presence of acetic acid, or a mixture of an acid and at least one organic solvent, and a catalytic system consisting of ferric nitrate nonahydrate, sodium chloride and 2,2,6,6-tetramethylpiperidine-1-oxyl radical, or a derivative thereof, selected from the group consisting of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl radical, 4-methoxy-2,2,6,6 -tetramethylpiperidine-1-oxyl radical, 4-(benzoyloxy)-2,2,6,6-tetramethylpiperidine-1-oxyl radical, 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxyl radical and 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl radical; wherein each of the catalytic system components is present in a molar ratio of 15% to 25% in moles with respect to 17α-(3-hydroxypropyl)-6β,7β;15β,16β-dimethylene -5β-androstane-3β,5,17β-triol of the formula (II).