| abstract |
The present invention is related to a novel process for the preparation of ulipristal (I) that comprises reaction of 17-α-ethynyl-17-β-hydroxy-11-β-(4-N,N-dimethylamino phenyl)- 9-norpregna-4,9-diene-3-one (III) with phenyl sulphenyl chloride (IVa) or p-nitro phenyl sulphenyl chloride (IVb) in the presence of organic base and solvent to give sulfoxide (Va) or (Vb) respectively. Sulfoxides (Va) or (Vb) are reacted with alkali metal alkoxide in alcoholic solvent followed by treatment with aqueous acid. The present invention also relates to novel intermediate 11-β-(4-N,N-dimethylaminophenyl)-21(p- nitro-phenyl-sulphinyl)-19-norpregna-4(5), 9(10), 17(20) 20-tetraene, 3-one (Vb). |