Patent ID: 8933061
Filing Date: 2015-01-13
Classification: C07J

Abstract:
1. A process for the preparation of drospirenone, comprising the oxidation of 17α-(3-hydroxypropyl)-6β,7β,15β,16β-dimethylene-5β-androstan-3β,5,17β-triol of formula (II) with an oxidizing agent in an organic solvent in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl radical or of a derivative thereof and of hydroxylamine, said oxidation being followed by the addition of a protic acid, directly into the vessel where oxidation occurred, to complete the formation of drospirenone of formula (I) characterized in that said oxidizing agent is chosen from the group consisting of oxygen, mixtures of inert gas and oxygen, and air, and wherein said derivative of 2,2,6,6-tetramethylpiperidine-1-oxyl radical is chosen 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.