| abstract |
The invention provides a process for preparing eplerenone, which comprises the following steps: (1) in the presence of a side reaction inhibitor, 17α-hydroxyl-3-oxo-γ-lactone-pregn-4,9(11)-diene-7α,21-dicarboxylic acid methyl ester IV is selectively expoxidized on double bond in trichloroacetonitrile, oxidant and phosphate buffer system in solution, to prepare crude eplerenone; (2) the crude eplerenone is recrystallized to yield pure eplerenone. High pure eplerenone can be obtained by the method of the present invention, the purity of eplerenone can reach 99.5% and the yield is as high as 87%. The method of the present invention is suitable for production on an industrial scale. |