- Methylprednisolone intermediate debrominated product and preparation method thereof
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The invention discloses a methylprednisolone intermediate debrominated product and a preparation method thereof. According to the preparation method, a compound shown as a formula I is used as a raw material, and a dechlorination reaction, a bromination reaction, a debromination reaction and an oxidation reaction are sequentially performed to prepare a compound (debrominated substance) shown as aformula V. The preparation method has the advantages of short synthetic route, high yield, low cost and easily available raw materials, is suitable for industrial production, and has very high industrial value.
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Paragraph 0034; 0038; 0040; 0044
(2020/02/10)
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- Dehalogenation methodof 9-halogenated steroid compound and application
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The invention provides a dehalogenation method of a 9-halogenated steroid compound and application, and relates to the technical field of chemical synthesis. The dehalogenation method of the 9-halogenated steroid compound comprises the following steps: reacting a compound I with a hydrogen donor and an azo radical initiator to obtain a 9-dehalogenated product compound II of the 9-halogenated steroid compound. According to the dehalogenation method of the 9-halogenated steroid compound, a hydrogen donor adopts one or a combination of more of hypophosphorous acid and hypophosphite, formic acid and formate, organic silicon hydride, hydrazine compounds or cyclohexene, and an initiator adopts an azo free radical initiator. Reagents such as chromium, divalent chromium salt, trivalent chromium salt or tributyltin hydride which are high in toxicity and cause serious pollution to the environment are not used in the reaction, the method is green and environmentally friendly, the synthesis process is simple, convenient and easy to implement, and the production applicability is improved.
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Paragraph 0194-0196
(2021/01/11)
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- Metal-Free Iodine-Mediated Deoxygenation of Alcohols in the Position α to Electron-Withdrawing Groups
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The use of a substoichiometric amount of molecular iodine in the presence of PPh3 and pyridine effects a direct deoxygenation of primary and secondary alcohols in positions α to a variety of activating electron-withdrawing groups, including ketones, esters, amides, imides and nitrile groups.
- Pichon, Ma?va M.,Stauffert, Fabien,Addante-Moya, Luis G.,Bodlenner, Anne,Compain, Philippe
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p. 1538 - 1545
(2018/04/20)
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- REDUCTIVE DEHALOGENATION OF 21-IODO DERIVATIVES OF CORTICOSTEROIDS
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In the reactions of 21-iodo derivatives of corticosteroids with hydrogen sulfide and thiol-containing reagents in a medium of dipolar aprotic and amide protogenic solvents at room temperature reductive-deiodination reactions occur with the formation of 21-deoxycorticosteroids in quantitative yield.Reactions of solutions of 21-iodomethyl ketones, heated to 80 deg C, with hydrogen sulfide and thiol-containing reagents give not only reduction products, but also products of nucleophilic substitution at C21 in yields of 20-30percent.
- Mikhal'chuk, A. L.,Pschenichnyi, V. N.
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p. 1479 - 1485
(2007/10/02)
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- Process for preparing 3-enol ethers of 11β-hydroxy-Δ4 -pregnene-3-ones and derivatives thereof
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3-enol ethers of 11β-hydroxy-Δ4 -pregnene-3-ones are prepared by reacting triethylorthoacetate with an 11β-hydroxy-Δ4 -pregnene-3-one in a solvent which is at least 40% by weight or more ethanol and 60% by weight or less of a compatible oxygenated hydrocarbon liquid in the presence of an acid catalyst. This reaction forms a basis of a process for forming 6-halo-derivatives, particularly 6-chloro-Δ1,4,6 -pregnatrien -11β,17α,21-triol-3,20-dione.
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