Patent ID: 7057045

Claim:
A process for obtaining 17β-(substituted)-3-oxo-Δ 1,2 -4-azasteroid of formula (I) wherein R1 can be a linear or branched alkyl group having 1 to 4 carbon atoms; OR2, wherein R2 is a linear or branched alkyl radical having 1 to 4 carbon atoms; or NR3R4, wherein R3 and R4, equal or different, represent hydrogen or a linear or branched alkyl radical having 1 to 4 carbon atoms, comprising the steps of: a) cleaving the oxazolidinedione ring present in a 2-(substituted)-3-hydroxyoxazolidinedione of formula (IV): wherein R 1 has the same meaning as above and R 5 is selected between Br and trichioromethylsulfonyl; to obtain a 2-(substituted)-3-oxo-4-azasteroid of formula (V): wherein R 1 and R 5 have the same meaning as above; and b) removing the R 5 substituent present in said compound of formula (V), together with a hydrogen at position 1, to produce said 17β-(substituted)-3-oxo-Δ 1,2 -4-azasteroid of formula (I).