- Preparation method of norethindrone acetate (by machine translation)
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The invention discloses a preparation method of norethindrone acetate and belongs to the technical field of drug preparation and processing. The method uses 19 - demethyl -4 - androstenedione as a starting raw material, protects, acetylenically, hydrolyses and esterifies 4 steps to prepare the norethindrone acetate. To the preparation method of the norethindrone acetate, the defects of a traditional process are overcome, reaction conditions are mild, impurities are reduced, overall conversion rate is high, operation is simple and convenient, and the method is suitable for industrial production and has a wide market prospect. (by machine translation)
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Paragraph 0008; 0034-0035
(2020/11/23)
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- A 19-nor-4-androstene -3,17-dione method for the preparation of
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The present invention discloses a 19-nor-4-androstene-3,17-dione preparation method without chromium oxidation, wherein 19-hydroxymethyl-4-androstene-3,17-dione is adopted as a raw material, is subjected to 2-iodoxybenzoic acid oxidation and sodium chlorite oxidation in a solvent, and then is subjected to decarboxylation under an acid condition so as to obtain the product 19-nor-4-androstene-3,17-dione. The preparation method of the present invention has characteristics of no requirement of use of the hypertoxic chromium oxidant, high yield, high raw material conversion rate, easy oxidant recycling, and environmental protection, and is widely used for the industrial scale production.
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- PROCESS FOR ALKYNYLATING 16-SUBSTITUTED-17-KETO STEROIDS
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The invention relates to a process for ethynylating 16-methylene-17-keto steroids to the corresponding 16-methylene-17α-ethynyl-17β-hydroxy steroids by treatment with silyl-protected lithium acetylides followed by further desilylation. The resulting products are useful intermediates in the preparation of several pharmaceutically active agents, such as e.g. Nestorone? or melengestrol acetate.
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Page/Page column 20
(2013/07/05)
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- Doping in sport-2. Quantification of the impurity 19-norandrostenedione in pharmaceutical preparations of norethisterone
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The finding of measurable amounts of 19-norandrostenedione in norethisterone tablets prompted us to develop an assay to quantify this steroid. 19-Norandrostenedione is an anabolic steroid whose use in sport is prohibited by the World Anti-Doping Agency (WADA). The assay was developed using isotope dilution and liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the quantification of 19-norandrostenedione in norethisterone formulations, with [3,4-13C2]-19-norandrostenedione as the internal standard. The results showed amounts up to 1.01 ± 0.01 μg (mean ± S.E.M.) per tablet in those containing 5 mg of norethisterone or norethisterone acetate (0.02%, w/w) and up to 0.5 ± 0.01 μg (mean ± S.E.M.) per tablet (0.05%, w/w) in oral contraceptive tablets containing 0.35-1.5 mg of norethisterone or norethisterone acetate. No tablet tested exceeded the British Pharmacopoeia limit of 0.1% for this impurity.
- Walker, Christopher J.,Cowan, David A.,James, Vivian H.T.,Lau, Joanne C.Y.,Kicman, Andrew T.
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scheme or table
p. 335 - 340
(2009/06/08)
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- Sulfuric acid adsorbed on silica gel. A multipurpose acid catalyst
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A series of acid catalyzed reactions like the dehydration of alcohols, conversion of ketones to 1,3-dioxolanes and their hydrolysis, α, β- unsaturated ketones to enol ethers, and alcohols to methyl-methoxyethyl ethers are performed efficiently in high yield with sulfuric acid adsorbed on silica gel as catalyst.
- Chavez,Suarez,Diaz
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p. 2325 - 2339
(2007/10/02)
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