【作者】 谢建刚；

【导师】 朱利民；

【作者基本信息】 东华大学 ， 纺织化学与染整工程， 2011， 博士

【摘要】 高血压病是最常见的心血管疾病,也是全球范围内的重大公共卫生问题。由于高血压的频发性和容易引发心脑血管病、肾脏病的发生,使它成为了死亡的首位危险因素和致残的主要因素,因此防治高血压显得尤其重要。而肺动脉高压(PAH)属于高血压病的一种,是非常严重的致残或致死疾病。已经有一些用于治疗PAH的药物应用于临床,例如抗凝血类药物、利尿剂等等,口服内皮素受体拮抗剂波生坦就是其中一种。安贝生坦和达卢生坦也属于口服内皮素受体拮抗剂。安贝生坦于2007年被FDA批准上市。关于这两种药物,近些年文献报道集中在药理和合成目标分子上,而对合成中所需要的两种重要中间体以及此类药物的新剂型涉及较少。基于前人的工作,本论文完成了安贝生坦和达卢生坦的合成,探讨了中间体4,6-二甲(氧)基-2-甲磺酰基嘧啶合成情况。探讨了催化下含巯基化合物的碳酸二甲酯(DMC)甲基化反应情况及机理特征。并以聚乙烯吡咯烷酮(PVP)和聚丙烯腈(PAN)为载体材料,采用静电纺丝技术制备了含有抗高血压药物的两种类型载药纤维膜,对载药纤维膜的结构和性能进行了表征,评价了其体外药物缓释性能。主要研究成果总结如下：(1)以2-巯基苯并噻唑(MBT)与DMC合成2-甲硫基苯并噻唑为模型反应,研究了季铵盐型相转移催化剂与K2CO3联用的催化效果。考察几种反应条件对反应的影响情况。从实验结果分析,Bu4NBr催化效果最好；甲基化反应最佳物料配比为：n(MBT):n(DMC):n(K2CO3):n(Bu4NBr)=1:18：1.5：0.2,90℃下反应3小时,收率76.4%；副产物为N-甲基化物,讨论了生成副产物的可能机理。同时对几类含巯基的杂环化合物的甲基化做了初步探索,发现DMC用于巯基的甲基化是方便而有效的。特别是4,6-二甲基-2-巯基嘧啶的巯基甲基化反应,高收率获得4,6-二甲基-2-甲硫基嘧啶,对优化4,6-二甲基-2-甲磺酰基嘧啶的合成路线提供了有益帮助。所有目标化合物经1H NMR、13C NMR、MS确证其化学结构。(2)选用MBT与DMC合成2-甲硫基苯并噻唑为模型反应,研究了离子液催化下以及改变几种反应条件对该反应的影响情况。从实验结果分析,[Bmim]Cl是所考察对象中最好的催化剂；甲基化反应最佳物料配比为：n(MBT):n(DMC):n([Bmim]Cl)=1:2:2,110℃下反应3小时,收率82.0%,副产物为N-甲基化物。扩大反应底物的适应范围,对几类含巯基的杂环化合物甲基化做了初步探索。得到了一些反应规律：温度对反应产物的收率及副反应影响明显；脂肪烃类硫醇活性明显较低；芳香类和杂环类活性明显较高。考察了[Bmim]Cl的催化循环能力。对于所关注的4,6-二甲基-2-巯基嘧啶的巯基甲基化反应,以92.3%收率获得了甲基化产物,对合成4,6-二甲基-2-甲磺酰基嘧啶打下了基础。所有目标化合物经1H NMR、13C NMR,MS确证其化学结构。选用氢质子相对简单的2-巯基嘧啶作为目标物,利用1H NMR追踪反应物的氢质子化学位移变化情况,讨论了离子液催化下DMC甲基化可能的反应机理,推测含巯基的化合物和DMC甲基化反应符合BAl2反应机理,并提出了催化循环机理图。(3)完成了4,6-二甲基-2-甲磺酰基嘧啶合成。甲基化反应一步中,离子液[Bmim]Cl为溶剂和催化剂,4,6-二甲基-2-巯基嘧啶(DLMP)与DMC可在适宜条件下反应并以高收率得到4,6-二甲基-2-甲硫基嘧啶。确定了反应的最佳工艺条件：常压下,反应温度110℃,物料配比为n(DLMP)：n(DMC)：n([Bmim]Cl)=1:1.5:2,3小时反应,收率93.5%。[Bmim]Cl重复使用四次,收率略有下降。经氧化反应,以92.7%收率得到4,6-二甲基-2-甲磺酰基嘧啶。该工艺总收率86.7%；完成了4,6-二甲氧基-2-甲磺酰基嘧啶合成。以硫酸二甲酯(DMS)甲基化方法为参考,以2-硫代巴比妥酸为原料进行甲基化,收率66.7%。经氧化反应,以91.2%收率得到4,6-二甲氧基-2-甲磺酰基嘧啶。该工艺总收率60.8%。目标化合物经FTIR、1H NMR、13C NMR、MS确证其化学结构。完成了安贝生坦和达卢生坦这两种内皮素受体拮抗剂的全合成。以二苯甲酮为原料,经与氯乙酸甲酯进行Darzens缩合,然后该中间体在对甲苯磺酸催化下醇解,经碱条件下水解,生成2-羟基-3-甲氧基-3,3-二苯基丙酸。再以甲基叔丁基醚为溶剂,与(S)-对氯苯乙胺成盐反应进行对应异构体拆分,得到(S)-2-羟基-3-甲氧基-3,3-二苯基丙酸与(S)-对氯苯乙胺成的盐(9),总收率为20.5%。达卢生坦的合成：(9)与2-甲磺酰基-4,6-二甲氧基嘧啶缩合,然后调节反应溶液为酸性,得到目标化合物达卢生坦,该工艺总收率为16.8%。安贝生坦的合成：(9)与2-甲磺酰基-4,6-二甲基嘧啶缩合,经调节反应溶液为酸性,得到目标化合物安贝生坦,该工艺总收率为16.2%。对2-羟基-3-甲氧基-3,3-二苯基丙酸外消旋体的化学拆分效果进行了分析,确定了(S)-2-羟基-3-甲氧基-3,3-二苯基丙酸的液相分离条件。确定了达卢生坦和安贝生坦的液相分离条件。重要中间体和目标化合物经FTIR、1H NMR、13C NMR、MS确证其化学结构。(4)以安贝生坦为模型药物,应用静电纺丝技术以PVPK60为载体高分子材料制备出两组载药量不同的安贝生坦／PVP载药纳米纤维膜,确定了电纺过程的工艺参数。对所制备的载药纤维进行了表征和体外快速溶解实验,结果表明：SEM显示药物分子很好地分散于PVP高分子中,随着PVP载药纳米纤维中载药量的增加,载药纤维的表面没有安贝生坦药物晶体析出。DSC和XRD分析表明药物分子很好地分散于PVP高分子中,IR分析表明药物安贝生坦与PVP之间能以氢键方式相结合,两者具有较好的相容性。体外快速溶解实验结果表明PVP载药纳米纤维具有明显的快速溶解现象,对可能的原因做了解释。这种快速溶解的载药纤维膜可能在高血压药物的新剂型上有所应用。(5)以卡托普利(Cpl)为模型药物,应用静电纺丝技术以PAN为载体高分子材料制备出三组载药量不同的Cpl/PAN载药纳米纤维膜,确定了电纺过程的工艺参数。对所制备的载药纤维进行了表征和体外释药性研究,结果如下：SEM显示药物分子很好地分散于PAN高分子中,随着PAN载药纳米纤维中载药量的增加,载药纤维的表面没有Cpl药物晶体析出。DSC和XRD分析表明药物分子很好地分散于PAN高分子中,IR分析表明药物Cpl与PAN之间能以氢键方式相结合,两者具有较好的相容性。体外溶出实验结果表明PAN载药纳米纤维具有明显的初期突释现象,随着PAN载药纳米纤维中载药量增加,初期突释现象更加明显,而药物释放度也会随之提高。载药纤维(d)的最高释放量在48小时内达到79.7%。拟合结果表明,PAN载药纳米纤维(d)释放最符合Ritger-Peppas模型。按照Ritger-Peppas方程处理三种载药纳米纤维1-8小时的药物释放数据,结果表明药物按照扩散机制从所制备的载药纳米纤维中释放出来。这种载药纤维可能在治疗高血压病的透皮给药系统上具有实际应用价值。更多还原

【Abstract】 Hypertension is a very common and serious condition that can lead to many health problems. It is also an important worldwide public-health challenge because of its high frequency and concomitant risks of cardiovascular and kidney disease. It has been identified as the leading risk factor for mortality, and is ranked third as a cause of disability-adjusted life-years. Therefore cost effective approaches to optimally control blood pressure are very much needed. Pulmonary arterial hypertension (PAH) is perhaps one of the most severe and disabling type of hypertension. PAH disease progression leads to right heart failure and death. Treatment options for PAH include various standard cardiovascular drugs, such as anticoagulants, diuretics and so on. A number of agents specifically approved for PAH have also been available for several years. The oral endothelin-receptor antagonist bosentan is one of these. As two other endothelin-receptor antagonists, ambrisentan and darusentan have been assessed in clinical trials for PAH, and ambrisentan has been FDA-approved for this indication in 2007. In recent years, much research work has been done in preparation of ambrisentan and darusentan, but most reports focus on the synthesis of the targeted molecule. The intermediates in the process of preparation and the new dosage forms about these drugs have not been discussed.Base on the fruit of those works, the processing, the affecting factors and announcements in the process of preparation for ambrisentan and darusentan are primarily discussed in this paper. The two intermediates,4,6-Dimethyl-2-(methylsulfonyl)pyrimidine and 4,6-Dimethoxy-2-(methylsulfonyl)pyrimidine were synthesized. The possible mechanism of S-methylated and the effect of by product formation were discussed. And then ambrisentan and darusentan were prepared. As the new dosage forms, drug-loaded nanofibres have been successfully prepared by an electrospinning technique, using ambrisentan or captopril as model drug. The structures of the electrospun drug-loaded nanofibers were characterized. And the in vitro dissolution tests were also systematically examined. The main research can be summarized as following:(1) 2-(Methylthio)benzothiazole was synthesized from 2-mercaptobenzothiazole(MBT) and dimethyl carbonate(DMC) in the presence Phase-transfer catalyst(PTC) and K2CO3. The processing, the affecting factors and announcements in the process of preparation for 2-(Methylthio)benzothiazole were discussed. Tetrabutylammonium bromide(Bu4NBr) was the best PTC. The optimum reaction conditions were n(MBT):n(DMC):n(K2CO3): n(Bu4NBr)=1:18:1.5:0.2, reaction temperature 90℃under atmospheric pressure, and reaction time 3h. The yield of 2-(Methylthio)benzothiazole was 76.4% while the conversion of MBT was 100% under these conditions. Meanwhile, the results of GC-MS showed that the byproducts were N-methylated derivative. The possible formation mechanism of N-methylated derivative and the effect of by product formation on the yield of 2-(Methylthio)benzothiazole were discussed. The S-methylated of some kinds of SH-containing heterocycles with DMC was studied in the presence of K2CO3 and Bu4NBr under the same conditions. Methylation with DMC has been found to be a convenient method to prepare heteroaryl methyl thioethers. K2CO3-Bu4NBr showed a high catalytic activity for SH-methylating types of mercapto group on heterocyclic rings. SH-containing heterocycles can be converted into their corresponding thioethers in high selectivity and yields. Therefore, it provides an alternative clean and easy route to S-methylated of SH-containing heterocycles and is help to synthesize 4,6-Dimethyl-2-(methylsulfonyl) pyrimidine. The structures of products were determined by 1HNMR,13CNMR and MS.(2) In order to investigate the catalytic activity of room temperature ionic liquids(RTILs) and the effect of other conditions, the reaction of MBT with DMC was selected as a model reaction. [Bmim]Cl was the best catalyst. The optimum reaction conditions were n(MBT): n(DMC):n([Bmim]Cl)=1:2:2, reaction temperature 110℃under atmospheric pressure, and reaction time 3h. The yield of 2-(Methylthio)benzothiazole was 82.0% while the conversion of MBT was 100% under these conditions. The byproducts were N-methylated derivative. The S-methylated of some kinds of SH-containing thiols with DMC was studied in the presence of [Bmim]Cl under the same conditions. Results indicated that the alkyl thiols were found to lower the reactivity. Higher yields of aryl methyl thioethers were obtained compared to alkyl methyl thioethers. Heterocyclic thiols were converted into the corresponding heteroaryl methyl thioethers giving high yields and good regioselectivity. Clearly temperature is an influencing factor on the yields and reaction time. We further investigated the recyclability of ionic liquid. [Bmim]Cl was further recycled in four subsequent runs with little decrease in activity. The yield of 4,6-dimethyl-2-(methylthio) pyrimidine was 92.3%. And this research lays a foundation for the preparation of 4,6-Dimethyl-2-(methylsulfonyl)pyrimidine. The structures of products were determined by 1H NMR,13C NMR and MS. To study the possible mechanism relating to the S-methylated using DMC in [Bmim]Cl, the change of proton chemical shift of mercapto group of the pyrimidine was investigated using 1H NMR. Results indicated that the possible mechanism relating to the S-methylated is BAl2 mechanism.(3) 4,6-Dimethyl-2-(methylsulfonyl)pyrimidine was synthesized from 4,6-dimethyl-2-mercaptopyrimidine(DLMP) by the methylation and oxidation via environment-friendly processes. The optimum reaction conditions in the methylation were n(DLMP):n(DMC):n([Bmim]Cl)=1:1.5:2, reaction temperature 110℃under atmospheric pressure, and reaction time 3h. The yield of 4,6-dimethyl-2-(methylthio)pyrimidine was 93.5%. [Bmim]Cl can be recycled in four subsequent runs with only a gradual decrease in activity. The yield of the oxidation was 92.7%. And the total yield of 4,6-Dimethyl-2-(methylsulfonyl) pyrimidine was 86.7%.4,6-Dimethoxy-2-(methylsulfonyl) pyrimidine was synthesized from 2-thlobarblturic acid(TBA) by the methylation and oxidation via environment-friendly processes. The yield of 4,6-Dimethoxy-2-(methylthio)pyrimidine was 66.7%. The yield of the oxidation was 91.2%. And the total yield of 4,6-Dimethoxy-2-(methylsulfonyl)pyrimidine was 60.8%. The structures of products were determined by FTIR,1H NMR,13C NMR and MS.Ambrisentan and darusentan, two ETA selective endothelin receptor antagonists, were synthesized using diphenyl ketone as a starting material. The target compound was synthesized via several steps, involving in Darzens condensation with ethyl chloroacetate, methanolysis catalyzed by p-toluene sulfonic acid, alkaline hydrolysis, and salt-formation. The total yield of (S)-p-Chlorophenylethylammonium-(S)-2-hydroxy-3-methoxy-3, 3-diphenylprop-ionate(9) was 20.5%. Darusentan was obtained via two steps, involving in a nucleophilic substitution by treating (9) with 4,6-Dimethoxy-2-(methylsulfonyl)pyrimidine in the presence of LiNH2 and acidizing with dilute sulfuric acid. The process for the synthesis of darusentan achieved a total yield of 16.8%. Ambrisentan was obtained via two steps, involving in a nucleophilic substitution by treating (9) with 4,6-Dimethyl-2-(methylsulfonyl)pyrimidine in the presence of LiNH2 and acidizing with dilute sulfuric acid. The process for the synthesis of ambrisentan achieved a total yield of 16.2%. The HPLC methods were established for the enantiomeric separation and determination of intermediate, darusentan and ambrisentan. The chemical structures of the target compounds were verified using FTIR,1H NMR,13C NMR and MS.(4) Drug-loaded nanofibre membranes have been successfully prepared by an electrospinning technique, using ambrisentan, polyvinylpyrrolidone K60 (PVP K60) and dimethylacetamide (DMAC) as the starting materials. The effect of fabrication parameters was determined. The structures of the electrospun drug-loaded nanofibers were characterized by SEM, DSC and XRD et al. The results indicated that the products were the three-dimensional continuous web structure nanofibres with 300-600 nm in average outer-diameter. The state of ambrisentan in the nanofibres was also discussed. Results from SEM, DSC and XRD showed that the drug was distributed evenly in nanofibers. FTIR results demonstrated that the main interactions between PVP and ambrisentan were hydrogen bonding. In vitro wetting and dissolution tests showed that the drug-loaded nanofiber membranes were able to absorb water and dissolve on the water surface in 60s through the polymer-controlled mechanism. The drug-loaded nanofibers obviously improved ambrisentan’s solubility. The Drug-loaded PVP nanofiber was useful for the possible applications as new dosage forms of antihypertensive drugs.(5) Ultrafine captopril(Cpl)-loaded polyacrylonitrile(PAN) fibers were successfully prepared by electrospinning method from co-dissolving solutions of PAN and captopril in dimethylacetamide (DMAC) as the spinning solutions. The effect of fabrication parameters was determined. The samples thereby obtained were characterized by SEM, DSC, XRD and FTIR measurements. SEM was carried out to observe the morphology of the nanofibers. DSC and XRD were conducted to clarify the states of the drug. FTIR was conducted to clarify the interactions between the drug and the polymer. Drug release profiles were investigated using in vitro dissolution tests. Results from SEM, DSC and XRD showed that the drug was distributed evenly in PAN nanofibers. FTIR results demonstrated that the main interactions between PAN and Cpl were hydrogen bonding. In vitro release study showed that after a burst release at the early stage, a sustained release was achieved and 79.7% of Cpl was released from the sample in 48h. It was shown that the drugs were capsulated inside of the fibers and the drug release in the presence of Cpl followed nearly Ritger-Peppas model. All the results demonstrated that the Drug-loaded PAN nanofiber was useful for the possible applications as transdermal drug delivery systems.更多还原