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50733-54-5

9-Bromo-11,17,21-trihydroxypregn-4-ene-3,20-dione 21-acetate synthesis

4synthesis methods
-

Yield:50733-54-5 67 g

Reaction Conditions:

with tetrafluoroboric acid;1,3-dibromo-5,5-dimethylimidazolidine-2,4-dione;water in acetone at -5;Reagent/catalyst;Temperature;

Steps:

1.1-1.3 1) Bromo-hydroxyl reaction

50 grams of 17α-hydroxypregna-4,9(11)-diene-3,20-dione-21-acetate (1) is added to 1500 ml of acetone, and the mass concentration is 10%50ml fluoroboric acid aqueous solution, cool to -5, add 60g of dibromodimethylhydantoin and stir to react. After the reaction is completed, neutralize with 10% sodium carbonate aqueous solution by mass concentration, concentrate the organic solvent, and hydrate. , Filtered to obtain 67 g of intermediate (2).

References:

CN111518151,2020,A Location in patent:Paragraph 0026-0027; 030-0031; 0034-0035

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