4571-51-1

Upstream product

• 1178555-52-6 9β,11-epoxy-16α-methyl-3,17,21-trihydroxy-1,3,5-triene-20-one 21-acetate 3-(4-nitrobenzoate) 
• 2884-51-7 17α,21-dihydroxy-9β,11β-epoxy-16α-methylpregna-1,4-diene-3,20-dione 21-acetate 
• 1997-73-5 9α-Bromo-6α-fluoro-11β,17α,21-trihydroxy-16α-methylpregna-1,4-diene-3,20-dione 21-acetate 
• 477898-18-3 9β,11β-epoxy-3,17α,21-trihydroxy-16α-methylpregna-1,3,5-triene-20-one 3-benzoate-21-acetate 

Downstream Products

• 2823-42-9 6α,9α-difluoro-11β,17α-dihydroxy-16α-methyl-21-acetoxypregna-1,4-diene-3,20-dione 
• 2607-06-9 6α,9-difluoro-11β,21-dihydroxy-16α-methylpregna-1,4-diene-3,20-dione 
• 2135-17-3 flumetasone 
• 23961-95-7 epoxyparamethasone 
• 4828-27-7 9α-chloro-6α-fluoro-11β,21-dihydroxy-16α-methyl-1,4-pregnadiene-3,20-dione 

Relevant academic research and scientific papers

PROCESS FOR THE PREPARATION OF 6-ALPHA-FLUORO PREGNANES

Disclosed is a process for the preparation of 6-α-fluoro pregnanes of formula I wherein R1 is an acyl group, R2 can be H, alpha methyl or beta methyl, and the dotted line can represent a double bond, comprising fluorination with electrophilic fluorinating agents in the 6 position of compounds of formula III, wherein R1, R2 and the dotted line have the meanings stated above, in an inert solvent, in the presence of a basic catalyst at temperatures ranging between 0 and 30° C.

PROCESS FOR THE PREPARATION OF 17-DESOXY-CORTICOSTEROIDS

The present invention provides an improved process for the preparation of 17-desoxy corticosteroid derivatives in a single chemical step by reacting the 17-hydroxy starting material with an excess of Trimethylsilyl Iodide. The present invention is specifically advantageous in preparing 17-desoxy corticosteroid derivatives having one or more halogen groups at positions 2, 6, 7 or 9 of the corticosteroid such as Clocortolone or Desoximetasone.

STEREOSELECTIVE METHOD OF PRODUCING 6ALPHA-FLUOROPREGNANES AND INTERMEDIARIES

6α-fluorpregnanes (I), where the dotted line between positions 1 and 2 represents a single or double bond; R1 is OH, OCOR2, X, SO3R3, or an (R7)(R8)(R9)SiO- group, where X is halogen, R2 and R3 are C1-6 alkyl or phenyl optionally substituted by C1-4 alkyl, and R7, R8 and R9, equal or different, are C1-6 alkyl or phenyl optionally substituted by C1-4 alkyl, can be obtained by means of a high stereoselectivity process comprising reacting a 3-(trisubstituted)silyloxy-pregna-3,5-diene (IV) with a fluorinating agent selected among N-fluorosulfonimides and N-fluorosulfonamides. The 6α-fluorpregnanes (I) are intermediates for the synthesis of steroids useful as anti-inflammatory and anti-asthmatic agents.

Selective epoxidation of steroidal bromohydrins

Vicinal steroidal epoxides are prepared by reacting the corresponding vicinal steroidal bromohydrin with a heterocyclic base such as 1,5-diazabicyclo[4.3.0]non-5-ene or 1,5-diazabicyclo[5.4.0]-undec-5-ene.