Eplerenone ethanol solvate.

EPLERENONE [SYSTEMATIC NAME: 7α-(methoxy-carbon-yl)-3-oxo-9α,11-ep-oxy-17α-pregn-4-ene-21,17-carbolactone], an aldo-sterone receptor antagonist, crystallizes from ethanol as a monosolvate, C(24)H(30)O(6)·C(2)H(6)O. The eplerenone mol-ecule has two five-membered rings, three six-membered rings and one three-membered ring. Both five-membered rings display envelope conformations, while the three six-membered rings assume envelope (cyclohexene), half-chair (cyclohexane sharing one edge with epoxy) and chair (other cyclohexane) conformations. The solvent mol-ecule is disordered equally over two sites. It is linked to the eplerenone mol-ecule by hydrogen bonds.