WO2019129308A1 - 甾体环氧异构体的循环利用方法 - Google Patents

甾体环氧异构体的循环利用方法 Download PDF

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WO2019129308A1
WO2019129308A1 PCT/CN2019/076372 CN2019076372W WO2019129308A1 WO 2019129308 A1 WO2019129308 A1 WO 2019129308A1 CN 2019076372 W CN2019076372 W CN 2019076372W WO 2019129308 A1 WO2019129308 A1 WO 2019129308A1
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recycling
epoxy
isomer
steroidal
organic solvent
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PCT/CN2019/076372
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杨坤
杨正业
黄瑞禄
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广西万德药业有限公司
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    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07JSTEROIDS
    • C07J71/00Steroids in which the cyclopenta(a)hydrophenanthrene skeleton is condensed with a heterocyclic ring
    • C07J71/0005Oxygen-containing hetero ring
    • C07J71/001Oxiranes
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00Technologies relating to chemical industry
    • Y02P20/50Improvements relating to the production of bulk chemicals
    • Y02P20/55Design of synthesis routes, e.g. reducing the use of auxiliary or protecting groups

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  • the invention relates to the field of pharmaceutical synthesis, in particular to a method for recycling steroidal epoxy isomers.
  • Steroid hormones refer to hormone drugs containing a steroid structure in the molecular structure. They are clinically important drugs, mainly including adrenal cortex hormones and sex hormones. Betamethasone is an important adrenal cortex hormone drug, which is the isomer of dexamethasone. It acts on the same as prednisolone and dexamethasone. It has anti-inflammatory, anti-rheumatic, anti-allergic and immunosuppressive effects. Pharmacological effects, betamethasone and its analogues have become one of the most widely used drugs in clinical practice.
  • the existing epoxy process inevitably gives two isomers of ⁇ and ⁇ , of which the content of the non-valued ⁇ epoxy isomer is 20%. -50%, the refined waste contains a large amount of discarded isomer ⁇ and a part of ⁇ isomer, which significantly reduces the utilization of raw materials and increases production costs.
  • the object of the present invention is to provide a method for recycling mild steroidal epoxy isomers, which solves the problems of the above-mentioned prior art, such as large safety hazards, environmental protection, low reaction yield, and high purity of intermediates.
  • the present invention proposes a recycling method of a steroidal epoxy isomer, and the specific technical scheme is as follows:
  • a recycling method of steroidal epoxy isomers, the synthetic route is as follows:
  • the epoxy ⁇ isomer and biphenyl are reacted with an active metal under an inert gas in an organic solvent to be reduced to a starting material.
  • the recycling method of the steroidal epoxy isomer is carried out by dissolving biphenyl, an epoxy isomer, and dissolving with an organic solvent, replacing the air with an inert gas, and adding a reactive metal.
  • the organic layer is extracted twice with dichloromethane, and the organic layer is extracted with water and saturated brine, dried over anhydrous sodium sulfate, and evaporated to dryness. The cake is washed with petroleum ether and dried to obtain a starting material.
  • the method for recycling the steroidal epoxy isomer, the molar ratio of the epoxy isomer, biphenyl, and active metal is 1: (2.5-3.5): (2.5-3.5) .
  • the method for recycling the steroidal epoxy isomer has a molar ratio of the epoxy isomer, biphenyl, and active metal of 1:3:3.
  • the weight ratio of the organic solvent to the epoxy isomer is 1w: 10v.
  • the method for recycling the steroidal epoxy isomer is one of tetrahydrofuran and dichloromethane.
  • the method for recycling the steroidal epoxy isomer is one or more of the active metals lithium, sodium and potassium.
  • the inert gas is one of nitrogen, helium, argon and helium.
  • the method for recycling the steroidal epoxy isomer is at a temperature of 20-30 ° C and a reaction time of 4-12 h.
  • the volume ratio of the dichloromethane extraction to the organic solvent is 0.7:1; the amount of the water extraction and the volume of the organic solvent The ratio is 1.3:1; the volume ratio of the saturated brine to the organic solvent is 1.3:1.
  • the method for recycling the steroidal epoxy isomer may further comprise diphenylmethane in a molar ratio of the diphenylmethane to the epoxy isomer of 0.6:1.
  • the invention has the following advantages:
  • the ketal protecting group is not affected, the 17-hydroxy group is not affected, the position of the double bond does not change, and it is directly converted into the raw material of the previous step, and can be recycled and recycled.
  • the one-step reduction of the present invention solves the existing common process of first opening the epoxy bond and then dehydrating it into a double bond, thereby avoiding the direct reduction of the epoxy bond to the double bond in the acidic environment. It will destroy the ketal protecting group; it solves the direct reduction of the epoxy isomer ⁇ and part of the ⁇ isomer to the raw material containing the conjugated double bond in the previous step, realizing a simple cycle.
  • Fig. 1 is a liquid phase spectrum of a reaction raw material Ul-I of the ulilistatin intermediate prepared in the first embodiment.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Steroid Compounds (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)

Abstract

本发明提供了一种甾体环氧异构体的循环利用方法,在联苯的有机溶剂中,与活泼金属锂、钠、钾等反应,还原成共轭双键;碱性环境下,缩酮保护基团不受影响,17-羟基不受影响,双键的位置不会发生变化,直接转化为上一步原料,得以回收循环利用。本发明的一步法还原,解决了要将环氧键先开环,再脱水成双键的现有常用工艺,避免了在酸性环境中金属将环氧键直接还原成双键,还会破坏缩酮保护基;解决了环氧异构体β及部分α异构体直接还原成上一步含共轭双键的原料,实现了一个简单的循环。

Description

甾体环氧异构体的循环利用方法 技术领域
本发明涉及药物合成领域,特别是涉及一种甾体环氧异构体的循环利用方法。
背景技术
甾体激素类药物(steroidhormonedrugs)是指分子结构中含有甾体结构的激素类药物,是临床上一类重要的药物,主要包括肾上腺皮质激素和性激素两大类。倍他米松作为重要的肾上腺皮质激素类药物,为地塞米松的同分异构体,作用于波尼松龙和地塞米松相同,具有抗炎、抗风湿、抗过敏和抑制免疫等多种药理作用,倍他米松及其类似物已成为临床使用最广泛的药物之一。
在乌利司他和米非司酮的合成过程中,现有的环氧工艺均无可避免的得到α和β两个异构体,其中无价值的β环氧异构体的含量占20-50%,精制后的废弃物中含有大量废弃的异构体β和部分α异构体,显著的降低了原料的利用率和增加了生产成本。
以上背景技术内容的公开仅用于辅助理解本发明的发明构思及技术方案,其并不必然属于本专利申请的现有技术,在没有明确的证据表明上述内容在本专利申请的申请日已经公开的情况下,上述背景技术不应当用于评价本申请的新颖性和创造性。
发明内容
本发明的目的在于提出一种条件温和、甾体环氧异构体的循环利用方法,已解决上述现有技术存在的安全隐患大、不环保、反应收率低、中间体纯度高的问题。
为此,本发明提出一种甾体环氧异构体的循环利用方法,具体技术方案如下:
一种甾体环氧异构体的循环利用方法,合成工艺路线如下:
Figure PCTCN2019076372-appb-000001
其中,环氧β异构体、联苯在有机溶剂中,在惰性气体的保护下与活泼金属反应,还原成起始原料。
优选地,所述的甾体环氧异构体的循环利用方法,所述的循环利用方法为将联苯、环氧异构体、用有机溶剂溶解之后,惰性气体置换空气,加入活泼金属,反应完毕,用二氯甲烷萃取两次,合并有机层,有机层依次用水、饱和食盐水萃取后,采用无水硫酸钠干燥,蒸干有机溶剂后,使用石油醚打浆、析晶、过滤,滤饼用石油醚洗涤,烘干,即得反应起始原料。
优选地,所述的甾体环氧异构体的循环利用方法,所述的环氧异构体、联苯、与活泼金属的摩尔比为1:(2.5-3.5):(2.5-3.5)。
进一步优选地,所述的甾体环氧异构体的循环利用方法,所述的环氧异构体、联苯、与活泼金属的摩尔比为1:3:3。
优选地,所述的甾体环氧异构体的循环利用方法,所述的有机溶剂与环氧异构体的重量体积比为1w:10v。
优选地,所述的甾体环氧异构体的循环利用方法,所述的有机溶剂为四氢呋喃、二氯甲烷的一种。
优选地,所述的甾体环氧异构体的循环利用方法,所述的活泼金属锂、钠、钾的一种或多种。
优选地,所述的甾体环氧异构体的循环利用方法,所述的惰性气体为氮气、氦气、氩气、氖气的一种。
优选地,所述的甾体环氧异构体的循环利用方法,所述的反应的温度为20-30℃,反应时间为4-12h。
优选地,所述的甾体环氧异构体的循环利用方法,所述的二氯甲烷萃取的用量与有机溶剂的体积比为0.7:1;所述的水萃取的用量与有机溶剂的体积比为1.3:1;所述的饱和食盐水萃取的用量与有机溶剂的体积比为1.3:1。
优选地,所述的甾体环氧异构体的循环利用方法,所述的反应中还可以加入二苯甲烷,所述的二苯甲烷与环氧异构体的摩尔比为0.6:1。
本发明与现有技术相比,优势有以下:
(1)碱性环境下,缩酮保护基团不受影响,17-羟基不受影响,双键的位置不会发生变化,直接转化为上一步原料,得以回收循环利用。
(2)本发明的一步法还原,解决了要将环氧键先开环,再脱水成双键的现有常用工艺,避免了在酸性环境中金属将环氧键直接还原成双键,还会破坏缩酮保护基;解决了环氧异构体β及部分α异构体直接还原成上一步含共轭双键的原料,实现了一个简单的循环。
附图说明
图1是本实施例1所制备出来的乌利司他中间体的反应原料Ul-Ⅰ的液相图谱。
具体实施方式
Figure PCTCN2019076372-appb-000002
一种甾体环氧异构体的循环利用方法,具体实验操作如下:
乌利司他的制备方法:
取10gUl-diene于250ml四口烧瓶中,加入100ml二氯甲烷溶解,依次加入5.5g六氟丙酮、8.9gNa 2HPO 4、120gH 2O、5.6g50%双氧水,0-5℃反应8h,TLC检测,反应完全。后处理:60ml5%硫代硫酸钠洗涤,60ml饱和碳酸氢钠洗涤,60ml饱和食盐水洗涤,无水硫酸钠干燥,旋去二氯甲烷,得10.9g,送HPLC,异构体α/β=2.6:1。
环氧异构体循环利用
Figure PCTCN2019076372-appb-000003
实施例1:
取联苯3.32g(3Eqv.),Ul-αorβ:3.0g(1Eqv.)于50ml三口瓶中加入,加入30ml二氯甲烷溶解,抽空通氮,加入锂块:0.14g(3.0Eqv.),30℃反应4h,加入8ml甲醇淬灭搅拌30min.加水稀释,21ml二氯甲烷萃取2次,合并有机层后分别用39ml水、39ml饱和食盐水萃取,无水硫酸钠干燥,45℃旋干得透明油状物,加人10ml石油醚打浆搅拌1h,析出白色固体,抽滤,石油醚洗涤,烘干得:3.05g,收率:91.8%,HPLC:94.0%。
实施例2:
取联苯2.57g(3.5Eqv.),二苯甲烷0.54g(0.6Eqv.),Ul-αorβ:2.0g(1Eqv.)于50ml三口瓶中加入,加入20ml四氢呋喃溶解,抽空通氦气,加入钠块:0.38g(3.5Eqv.),20℃反应6h,TLC检测有原料,及大极性杂点(可能是中间态),补加0.05g钠,再反应2h。绝大部分是产物,有极少原料。加入4ml甲醇淬灭搅拌30min,加水稀释,14ml二氯甲烷萃取2次,合并有机层,分别用26ml水、26ml饱和食盐水萃取,无水硫酸钠干燥,45℃旋干得透明油状物,加人10ml石油醚打浆搅拌1h,析出白色固体,抽滤,石油醚洗涤,烘干得:2.35g,收率:91.4%。HPLC:91.4%。
米非司酮的制备方法:
Figure PCTCN2019076372-appb-000004
取500mL二氯甲烷于三口烧瓶中,加入62g(1.0Eqv.)三水合六氟丙酮,71g(0.71Eqv.)十二水合磷酸氢二钠,冰水浴控温0-5℃,滴加64g50%双氧水(3.340Eqv.),搅拌反应30min。滴加500ml二氯甲烷+100gMf-diene的溶液,冰水浴控温0-5℃,磁力搅拌下反应10h。后处理:100ml5%硫代硫酸钠淬灭搅拌10min,200ml二氯甲烷萃取。有机相100ml饱和碳酸氢钠洗涤,再100ml饱和食盐水洗涤,无水硫酸钠干燥,旋去二氯甲烷。加入石油醚旋干带溶剂.析出固体得104g,送HPLC:α/β=3.3:1。
环氧异构体循环利用
Figure PCTCN2019076372-appb-000005
实施例3:
取联苯2.38g(2.5Eqv.),Mf-αorβ:2.19g(1.0Eqv.)于50ml三口瓶中加入,加入22ml四氢呋喃溶解,抽空通氩气,加入0.6g(2.5Eqv.)钾块,20℃搅拌反应12h。后处理:加入甲醇4ml淬灭,搅拌30min,加水稀释,15.4ml二氯甲烷萃取2次,合并有机层,分别用35.2ml水、35.2ml饱和食盐水萃取,无水硫酸钠干燥,45℃旋干得透明油状物,加人10ml石油醚打浆搅拌1h,析出不出固体,有不溶粘稠物,倾滤,再加入石油醚10ml,打浆,倾滤。旋干得2.18g,收率:91.6%,HPLC:94.56%。
实施例4:
取联苯2.50g(3.0Eqv.),Mf-αorβ:2.00g(1.0Eqv.)于50ml三口瓶中加入,加入20ml二氯甲烷溶解,抽空通氖气,加入钠0.37g(3.0Eqv.)块,30℃搅拌 反应8h。后处理:加入甲醇4ml淬灭,搅拌30min,加水稀释,14ml二氯甲烷萃取2次,合并有机层,分别用26ml水、26ml饱和食盐水萃取,无水硫酸钠干燥,45℃旋干得透明油状物,加人10ml石油醚打浆搅拌1h,析出不出固体,有不溶粘稠物,倾滤,再加入石油醚10ml,打浆,倾滤。旋干得2.29g,收率:91.6%,HPLC:93.27%。
以上内容是结合具体的/优选的实施方式对本发明所作的进一步详细说明,不能认定本发明的具体实施只局限于这些说明。对于本发明所属技术领域的普通技术人员来说,在不脱离本发明构思的前提下,其还可以对这些已描述的实施例做出若干替代或变型,而这些替代或变型方式都应当视为属于本发明的保护范围。

Claims (10)

  1. 一种甾体环氧异构体的循环利用方法,其特征在于,合成工艺路线如下:
    Figure PCTCN2019076372-appb-100001
    其中,环氧β异构体、联苯在有机溶剂中,在惰性气体的保护下与活泼金属反应,还原成起始原料。
  2. 如权利要求1所述的甾体环氧异构体的循环利用方法,其特征在于:所述的循环利用方法为将联苯、环氧异构体、用有机溶剂溶解之后,惰性气体置换空气,加入活泼金属,反应完毕,用二氯甲烷萃取两次,合并有机层,有机层依次用水、饱和食盐水萃取后,采用无水硫酸钠干燥,蒸干有机溶剂后,使用石油醚打浆、析晶、过滤,滤饼用石油醚洗涤,烘干,即得反应起始原料。
  3. 如权利要求2所述的甾体环氧异构体的循环利用方法,其特征在于:所述的环氧异构体、联苯、与活泼金属的摩尔比为1:(2.5-3.5):(2.5-3.5)。
  4. 如权利要求3所述的甾体环氧异构体的循环利用方法,其特征在于:所述的环氧异构体、联苯、与活泼金属的摩尔比为1:3:3。
  5. 如权利要求2所述的甾体环氧异构体的循环利用方法,其特征在于:所述的有机溶剂与环氧异构体的重量体积比为1w:10v。
  6. 如权利要求1-2任一项所述的甾体环氧异构体的循环利用方法,其特征在于:所述的有机溶剂为四氢呋喃、二氯甲烷的一种;所述的活泼金属锂、钠、钾的一 种或多种。
  7. 如权利要求1-2任一项所述的甾体环氧异构体的循环利用方法,其特征在于:所述的惰性气体为氮气、氦气、氩气、氖气的一种。
  8. 如权利要求1-2任一项所述的甾体环氧异构体的循环利用方法,其特征在于:所述的反应的温度为20-30℃,反应时间为4-12h。
  9. 如权利要求2所述的甾体环氧异构体的循环利用方法,其特征在于:所述的二氯甲烷萃取的用量与有机溶剂的体积比为0.7:1;所述的水萃取的用量与有机溶剂的体积比为1.3:1;所述的饱和食盐水萃取的用量与有机溶剂的体积比为1.3:1。
  10. 如权利要求1-2任一项所述的甾体环氧异构体的循环利用方法,其特征在于:所述的反应中还可以加入二苯甲烷,所述的二苯甲烷与环氧异构体的摩尔比为0.6:1。
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4386085A (en) * 1981-01-09 1983-05-31 Roussell Uclaf Novel steroids
CN102516345A (zh) * 2011-11-01 2012-06-27 上海优拓医药科技有限公司 醋酸乌利司他及其关键中间体的制备方法
CN107200770A (zh) * 2016-03-18 2017-09-26 华东师范大学 特拉司酮合成中环氧异构体的高效分离和循环利用方法
CN108070016A (zh) * 2017-12-29 2018-05-25 广西万德药业有限公司 甾体环氧异构体的循环利用方法

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016110874A2 (en) * 2015-01-07 2016-07-14 Ipca Laboratories Limited Process for preparation of artemisinin and its derivatives
CN106866778A (zh) * 2017-04-25 2017-06-20 广西万德药业有限公司 一种5(10)位α环氧甾族化合物的合成方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4386085A (en) * 1981-01-09 1983-05-31 Roussell Uclaf Novel steroids
CN102516345A (zh) * 2011-11-01 2012-06-27 上海优拓医药科技有限公司 醋酸乌利司他及其关键中间体的制备方法
CN107200770A (zh) * 2016-03-18 2017-09-26 华东师范大学 特拉司酮合成中环氧异构体的高效分离和循环利用方法
CN108070016A (zh) * 2017-12-29 2018-05-25 广西万德药业有限公司 甾体环氧异构体的循环利用方法

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