- Preparation method of deprodone propionate
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The invention relates to a preparation method of deprodone propionate. The preparation method comprises the following steps: dissolving a mildew extract with a relatively price, as a raw material, into an organic solvent, adding pyridine, and introducing sulfur trioxide to dehydrate 11-site a hydroxyl, so as to obtain a dehydrated object; dissolving the dehydrated object into the organic solvent to epoxidize a 11-site double bond under the catalysis of caustic soda, so as to obtain an epoxidized object; dissolving the epoxidized object into the organic solvent to generate reaction by virtue ofa double epoxy bond with hydrobromic acid under the catalysis of acetic anhydride, so as to obtain dibromide; carrying out reduction debromination on dibromide molecules, so as to obtain deprodone; and finally carrying out propionylation on deprodone, so as to obtain deprodone propionate. The total yield by weight of the above five steps is 60-65%, and the HPLC content of the final product is 99.0% or above. The preparation method has the beneficial effects that a synthetic route is reasonable in design, the production raw materials are cheap and easily available, the process operation is simple and environmentally friendly, the total yield is high, the product quality is good, and the production cost is 20%-25% lower than a traditional method; and furthermore, the reaction solvent can berecycled and circularly used, so that the method is economic, environmentally friendly and very suitable for industrial production.
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Paragraph 0015; 0020; 0025
(2018/04/01)
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- A process for the preparation of prednisolone
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The application relates to a method for synthetizing prednisolone. Double bond bromination, reductive debromination, bromination and hydrolysis reaction are carried out on a compound with a structure of formula I so as to generate the prednisolone. The method is high in yield, is easy to operate, and is applicable to industrial production.
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Paragraph 0029
(2016/10/07)
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- Process for the preparation of 21-desoxy-17-acyloxy-4-pregnenes and of 21-iodo-21-desoxy-17-acyl oxy-4-pregnene intermediates useful therein
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21-Desoxy-17α-acyloxy-20-keto-4-pregnenes having physiological properties are prepared by the reaction of a 17α,21-dihydroxy-20-keto-4-pregnene 17α,21-orthoester or a 21-iodo-21-desoxy-17α-acyloxy-20-keto-4-pregnene with an iodide reagent selected from the group consisting of triphenylsilyl iodide, tri-lower alkylsilyl iodide and triphenylmethyl iodide. When said 17α,21-dihydroxy-20-keto-4-pregnene 17α,21-orthoester is reacted with less than two molar equivalents of a tri-lower alkylsilyl iodide reagent there is also formed a 21-iodo-21-desoxy-17-α -acyloxy-20-keto-4-pregnene, a useful intermediate, which, upon reaction with additional iodide reagent, is converted to the corresponding 21-desoxy-17α-acyloxy-20-keto-4-pregnene.
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