- An efficient procedure for the synthesis of 21-acetoxypregna-1,4,9(11),16-tetraene-3,20-dione
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Background: Halogenated corticosteroids are widely used in medicine, and the global need of these steroidal APIs is estimated to be 40 - 70 tons, annually. Vietnam currently imports the pharmaceutical compounds up to 90%, in particular 100% of steroidal drugs. Currently, industrial production is based on the chemical syntheses of corticosteroids from either 16-dehydropregnenolone acetate (obtained from diosgenin) or androstenedione (obtained from phytosterol). The development of shorter synthetic schemes and more economically feasible technologies is of great significance. Introduction of 1(2)-double bond at the final stages of the corticosteroids synthesis results inpoor yield. 21-Acetoxypregna-1,4,9(11),16-tetraene-3,20-dione (tetraene acetate) is a key intermediate in the synthesis of highly active halogenated corticosteroids such as dexamethasone and other halogenated corticosteroids. 21-acetoxypregna-1,4,9(11),16-tetraene-3,20-dione is a key intermediate in the synthesis of dexamethasone from the readily available and cheap 9α-hydroxyandrost-4-ene-3,17-dione. Objective: The purpose of this study was the development of an efficient and shorter procedure for the synthesis of 21-acetoxypregna-1,4,9(11),16-tetraene-3,20-dione from 9α-hydroxyan-drostenedione, which is a product of a bio-oxidative degradation of the side chain of phytosterols. Methods: Pregnane side chain was constructed using cyanohydrin method. For 1(2)-dehydrogenation, selene dioxide was applied for the introduction of Δ1(2)-double bond. Other stages of the synthesis were epimerization, Stork’s iodination procedure and dehydration. Result: 21-Acetoxypregna-1,4,9(11),16-tetraene-3,20-dione was prepared from 9α-hydroxyandrostenedione in yield more than 46%. Conclusion: An efficient and practically feasible procedure for the synthesis of 21-acetoxypregna-1,4,9(11),16-tetraene-3,20-dione from 9α-hydroxyandrostenedione, a key intermediate for the synthesis of 9-haloidated corticoids, has been developed. The procedure can be applied for the production of value-added 9-haloidated corticoids.
- Huy, Luu D.,Diep, Nguyen T.,Vu, Tran K.,Savinova, Tatiana S.,Donova, Marina V.
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p. 225 - 231
(2020/04/27)
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- Synthesis method of triene acetate compound
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The invention belongs to the technical field of steroid hormone preparation, in particular to a synthesis method of a triene acetate compound. The preparation method comprises the following steps: under the participation of 4-dimethylaminopyridine, removing 17-site hydroxyl of the anecortave acetate by using an N-chlorosuccinimide and a sulfur dioxide pyridine solution; and after the reaction is finished, performing crystallization to obtain the triene acetate compound. The 4-dimethylaminopyridine is added into the reaction system, an intermediate is stabilized, generation of rearrangement impurities is well inhibited, and the content of the rearrangement impurities in the system is reduced from 12% to 2%, so that the triene acetate compound is obtained at a high yield, with the purity reaching 99%, and the yield being 80% or above.
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Paragraph 0011-0012; 0017-0018; 0021-0022
(2020/02/10)
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- Preparation method of halcinonide and derivative thereof
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The invention provides a preparation method of halcinonide and a derivative thereof. The method comprises the following steps: taking hydrocortisone acetate as a raw material, performing dehydration and then epoxidation on the raw material, performing ring opening, performing hydrolysis and chlorination, and then performing oxidation and ketalization, so as to obtain halcinonide; or performing dehydration and then epoxidation on the raw material, performing ring opening, performing hydrolysis, and then performing oxidation and ketalization, so as to obtain 9-fluoro-16a,17-(isopropylidenedioxy)corticosterone. In ring opening fluorination unit reaction, safe and mild reaction environment is selected, a fluorizating agent with low concentration is used as a reaction reagent, the reaction rate is effectively controlled, the production of side reaction products is restrained, and the product quality and yield are greatly improved. Moreover, in 16, 17-ketalization unit reaction, an acid catalyst which is low in toxicity and easy to control is adopted to replace boron trifluoride with high toxicity to perform catalysis, and the catalytic effect is effectively improved.
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Paragraph 0110-0112; 0120; 0123
(2018/03/26)
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- Preparation method of delta 16 steroid
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The invention relates to a preparation method of a delta 16 steroid. At the atmosphere of protective gas, a compound of a formula II, an oxidizing agent and sulfur dioxide are subjected to a reaction in an organic solvent, the reaction temperature ranges from minus 50 DEG C to 0 DEG C, and the reaction time is 1.5-2.5 h to obtain a delta 16 steroid I, wherein R1 is selected from H, halogen and acyloxy or hydroxide of C1-5; R2 is selected from alkyl of alpha C1-3 and alkyl or H of beta C1-2; R3 is selected from H, alkyl of alpha C1-3, alkyl of beta C1-2, alpha halogen or beta halogen; R4 and R5 are equal to H or double bonds; R7 is selected from H, and R6 is selected from H, alkyl of C1-3 or acyloxy of C1-5; or R6 and R7 are equal to double bonds. According to the preparation method of the delta 16 steroid, the 17-bit hydroxide compound of the formula II is used as raw materials, and the compound of the formula II is industrially produced and is easy to obtain; the preparation method is mild in reaction condition, no high-temperature strong base or strong acid is needed, fewer by-products are produced, the product yield and purity are high, the yield reaches more than 90%, and the purity reaches more than 93%.
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Paragraph 0082; 0083; 0084; 0085; 0086
(2016/10/07)
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- Method for preparing tetraene acetate and derivatives thereof
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The invention relates to a method for preparing tetraene acetate and derivatives thereof. The method comprises the steps of obtaining a compound II through etherification reaction of a compound I and an etherification agent in the atmosphere of protective gases, obtaining a compound III through addition reaction of the compound II and a reagent A under the action of strong base and hydrolysis and elimination reaction of the compound II and the reagent A in the presence of an acid solution, obtaining a compound IV through substitution reaction and rearrangement reaction of the compound III and acetate, and conducting 1 position dehydrogenation and 2 position dehydrogenation on the compound IV to obtain the tetraene acetate and derivatives thereof. According to the method, the compound I is taken as the raw material and subjected to carbonyl etherification, addition, hydrolysis, elimination, rearrangement and dehydrogenation reaction to obtain the product, the raw material compound I is easy to obtain, cost is low, no precious metal is needed during preparation, reaction conditions are easy to control, operation is convenient, the method is suitable for large-scale industrial production, and the obtained tetraene acetate is an important intermediate for synthesis of dexamethasone, budesonide, betamethasone and other steroidal drugs.
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- Process for preparing Δ9(11) and/or Δ16 -unsaturated sternoids
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A process for preparing a Δ9(11) - and/or Δ16 -unsaturated steroid comprises heating the corresponding steroid of the pregnane series substituted by 9α-chloro- and/or 16α-chloro- or 17α-acyloxy, in an inert, aprotic high-boiling solvent at 180°-350° C.
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- Process for the preparation of 21-hydroxy-16-pregnen-20-one derivatives
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Δ16 -21-HYDROXY-20-KETO STEROIDS OF THE PREGNANE SERIES HAVING AN OTHERWISE UNSUBSTITUTED D-ring and a 13-methyl or -ethyl group, and 21-ethers and -esters thereof, are produced by reaction of a corresponding D-ring saturated 17-keto steroid with a lithium compound of the formula STR1 thereby converting the 17-keto group to a 17β-hydroxy-20α-enol ether in which the 17α-side chain has the formula STR2 wherein R3 and R4 have the values given above, and, in any desired sequence, splitting off R3 and/or R4 enol ether by hydrolysis; eliminating 17β-hydroxy group, preferably after acylation, with formation of a Δ16 -double bond; and, if desired, splitting off any blocking group.
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