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US 10,538,551 B2Granted
Process for preparation of corticosteroids
AssigneeCoral Drugs Pvt. Ltd.
InventorsVinayak Tripathi, Rajesh Kumar, Rohit Bhuwania, Binay Kumar Bhuwania
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Abstract
The present invention discloses a process for the preparation of pregnadiene derivatives having formula I, their stereoisomer and intermediate thereof. Formula I wherein each substituent is independently, R1 and R2 is hydrogen or C1-C8 straight, branched alkyl chain, saturated or unsaturated cycloalkyl; R3 is hydrogen or wherein R5 represents C1-C8 straight, branched alkyl chain or cycloalkyl; R4 is hydrogen or halogen; R6 is hydrogen or halogen;
Claims8
A novel process for the preparation of pregnadiene derivatives of formula I and stereoisomers and intermediates thereof
- wherein:
- R1 and R2 are independently hydrogen or C1-C8 straight, branched alkyl chain, saturated or unsaturated cycloalkyl;
- R3 is hydrogen or
- R5 is C1-C8 straight, branched alkyl chain or cycloalkyl;
- R4 and R6 are independently hydrogen or halogen;
- comprising the steps of:
- i. epoxidation of compound of formula II to obtain 9,11-oxido derivative of compound of formula III
- i. dihydroxylation and optional fluorination of compound of formula III to obtain compound of formula IV wherein R6 is fluorine
- ii. epoxide ring opening of compound of formula IV followed by acetalisation in the presence of hydrohalic acid to with debromination of R4 from being bromine to hydrogen to obtain the compound of formula V
- iv. deacetylation of compound of Formula V to obtain compound of formula I
7 more elements
Dependencies are inferred from the claim text.