- Preparation process of 6-demethyl-6-deoxytetracycline
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The invention discloses a preparation process of 6-demethyl-6-deoxytetracycline. The preparation process comprises the following steps: sequentially adding demethylchlortetracycline and urea into softwater, uniformly mixing, reacting in a hydrogen environment by taking Pd/C as a catalyst, filtering the catalyst to obtain a compound I; dissolving the obtained compound I in alcohol, adding an acid,stirring until the compound I is completely dissolved, adding DMF, reacting in a hydrogen environment by taking Pd/C as a catalyst, filtering the catalyst to obtain a compound II; concentrating the compound II under a reduced pressure, recovering alcohol, drying, adding into soft water, adding urea for dissolving, filtering to obtain double salt; adding the double salt into alcohol, stirring for2 hours at a low temperature, and filtering to obtain a high-purity compound II. The preparation process has the beneficial effects that an isomer with a lactone structure is prevented from being generated by ring opening; the yield and the purity are improved; not only is the safety coefficient of production improved, but also the cost loss caused by the loss of an organic solvent is reduced; thereaction temperature is reduced, the product purity is improved; and the epimers are reduced.
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Paragraph 0037; 0045; 0047-0049; 0051-0053; 0055-0057; 0059
(2020/07/15)
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- Preparation method of minocycline hydrochloride
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The invention provides a preparation method of minocycline hydrochloride. The preparation method comprises the following steps: 1) preparing sancycline: preparing the sancycline by taking demeclocycline hydrochloride as a raw material; 2) preparing 7-iodosancycline: under a strong acid condition, taking N-iodosuccinimide and the sancycline to react to prepare a reaction solution, namely the 7-iodosancycline; 3) preparing the minocycline hydrochloride: taking the 7-iodosancycline and dimethylaminotrimethyl tin to react in an amine solvent and an amide solvent under the action of a palladium complex catalyst to prepare a reaction solution, and adjusting the pH (Potential of Hydrogen) of the reaction solution to be 0.8 to 1.0 with concentrated hydrochloric acid; after de-coloring with active carbon, adjusting the pH of the reaction solution to be 3.8 to 4.0 with ammonia water; freezing and crystallizing; after filtering, drying a filter cake to obtain the minocycline hydrochloride. The minocycline hydrochloride prepared by the preparation method has the advantages of low cost, stable structure, few isomer impurities, low content of epimers and relatively high product purity.
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- SEMI-SYNTHESIS PROCEDURES
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Provided herein are improved processes tor convening C7-amino-substituted tetracyclines to C7-fluoro-substituted tetracyclines, as well as intermediates produced by or used in these processes. In one embodiment, a thermal fluorination method is provided in which a suspension comprising a non-polar organic solvent and a C7-diazo-substituted tetracycline hexafluorophosphate, hexafluoarsenate or hexafluorosilicate salt, or a salt, solvate or combination thereof, is healed to provide a C7-fluoro-substituted tetracycline, or salt, solvate or combination thereof. In another embodiment, a photolytic fluorination is provided in which a solution comprising an ionic liquid and a C-7diazo-substituted tetracycline tetrafluoroborate, hexafluorophosphate, hexafluoroarsenate or hexafluorosilicate salt, or a salt, solvate or combination thereof, is irradiated to provide a C7-fluoro-substituted tetracycline, or salt, solvate or combination thereof.
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Paragraph 00172
(2016/05/24)
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- A mountain of tigecycline preparation method
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The invention discloses a preparation method for sancycline. The preparation method comprises the step of subjecting a compound I to a reaction in a mixed solvent of alcohol and acid in a hydrogen environment under the action of a catalyst so as to obtain a compound II, wherein the alcohol is C1 to C6 alcohol, and the acid is one selected from the group consisting of sulfuric acid, hydrobromic acid, methanesulfonic acid, p-toluenesulfonic acid, perchloric acid and phosphoric acid with weight percentage of 85%. The preparation method provided by the invention has the advantages of high yield, a few reaction by-products, high purity, simple and convenient process, easy post-treatment, recoverability of the solvent and the catalyst, small environmental protection pressure, low cost and suitability for industrial production.
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Paragraph 0031; 0032; 0033; 0034; 0035; 0036-0050
(2017/06/19)
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- TETRACYCLINE COMPOUNDS FOR THE TREATMENT OF RHEUMATOID ARTHRITIS AND RELATED METHODS OF TREATMENT
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The present invention pertains, at least in part, to substituted tetracycline compounds. The present invention also pertains to methods for treating rheumatoid arthritis in a subject, comprising administering to the subject a tetracycline compound of the invention.
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Page/Page column 36
(2010/04/25)
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- 10-substituted tetracyclines and methods of use thereof
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10-Substituted tetracycline compounds are described.
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Page/Page column 32
(2010/11/26)
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