H^+在羟基乙酸甲酯合成中的催化作用研究

在微型高压反应釜中 (12 0ml) ,考察了酸催化三聚甲醛和甲酸甲酯制备羟基乙酸甲酯的偶联反应 ,并对酸催化剂中H+的作用进行了研究。在该偶联反应体系中 ,H+浓度直接影响着甲酸甲酯的分解速率和羟基乙酸甲酯的收率。甲酸甲酯在偶联反应中是以CO和CH3OH的载体形式而存在。在H+的催化作用下 ,该偶联反应机理可分三步完成 :(a)H+的催化作用促使甲酸甲酯分解产生CO和CH3OH ,三聚甲醛分解形成羟甲基正离子和甲氧基甲基正离子HOC H2 ;(b)羟甲基正离子CH3OC H2 和甲氧基甲基正离子与CO进行羰化作用形成产物中间体或过渡态化合物 ;(c)中间体或过渡态化合物的甲醇醇解形成羟基乙酸甲酯、甲氧基乙酸甲酯和乙醇酸。

气相色谱法测定格隆溴铵起始原料α-环戊基-α-苯基-α-羟基乙酸甲酯的残留溶剂

目的建立气相色谱法测定格隆溴铵起始原料α-环戊基-α-苯基-α-羟基乙酸甲酯的残留溶剂。方法以N,N-二甲基甲酰胺(DMF)为溶剂,采用KB-624毛细管色谱柱(30 m×0.53 mm,3μm);氢火焰离子化检测器(FID);载气:氮气;进样口温度:200℃;检测器温度:250℃;程序升温:起始柱温35℃,保持6 min,以20℃·min-1的速率升至160℃,保持7.75 min;分流比为5︰1;进样量1μL。结果甲醇、乙醚、溴乙烷、苯乙烯均能有效分离,分别在0.0800~0.3200、0.1315~0.5260、0.0032~0.0130、0.0027~0.0111mg·m L^-1浓度范围内线性良好(R>0.999),平均回收率为96.5%~99.4%。结论该方法简便、准确,适用于α-环戊基-α-苯基-α-羟基乙酸甲酯中残留溶剂的测定,可为其质量控制提供科学依据。

强酸性阳离子交换树脂催化合成对羟基苯乙酸甲酯

以对羟基苯乙酸和甲醇为原料，强酸性阳离子交换树脂为催化剂，研究了催化剂种类、反应时间、反应温度、原料配比、催化剂用量及催化剂重复使用次数对反应的影响，确定了反应的最佳工艺条件为：反应温度为65—70℃，反应时间为4h，醇酸摩尔比为4：1，催化剂用量为反应物料总质量的1．5％，酯化收率为85．O％，产品纯度可达到98．5％。使用的催化剂732型强酸性阳离子交换树脂不经处理可重复使用10次以上，显示了较好的稳定性，同时具有催化活性好、价格低廉、不腐蚀设备、无环境污染等优点。

用HPLC测定羟基苯乙酸-N,N-二甲氨基甲酰甲酯含量的研究

以高效液相色谱法（HPLC）测定对羟基苯乙酸-N，N-二甲氨基甲酰甲酯的含量，采用Thermo Syneronis C18柱（250mm×4.6mm，5μm），以乙腈-水=30：70（V/V）为流动相，流速1.0mL/min，检测波长275nm。结果表明，对羟基苯乙酸-N，N-二甲氨基甲酰甲酯在0.1-1.0μg范围内线性关系良好，加样回收率为98.8%，RSD=1.08%。该方法准确，便捷，重现性好，适用于对羟基苯乙酸-N，N-二甲氨基甲酰甲酯的含量测定及工业生产中的质量控制。

对羟基苯乙酸-N,N-二甲基甲酰氨基甲酰甲酯的合成工艺研究

采用N,N-二甲基-2-氯乙酰胺、4-羟基苯乙酸、三乙胺等为原料,于乙腈中反应,HPLC跟踪检测合成对羟基苯乙酸-N,N-二甲基甲酰氨基甲酰甲酯(简称化合物B)。结果表明,最佳合成工艺参数为:反应时间12 h,反应温度60℃,溶剂用量为2 200 m L,物料比为n(4-羟基苯乙酸)∶n(N,N-二甲基-2-氯乙酰胺)=1∶1.10。在最佳条件下,收率86%,纯度98%以上。

对羟基苯乙酸-N,N-二甲氨基甲酰甲酯合成工艺优化研究

采用对羟基苯乙酸、氯代乙酰二甲胺、三乙胺为原料经反应合成对羟基苯乙酸-N,N-二甲基氨基甲酰甲酯。合成优化工艺条件为:n(对羟基苯乙酸)∶n(氯代乙酰二甲胺)=1∶1.0,n(对羟基苯乙酸)∶n(三乙胺)=1∶1.5,反应时间12 h,反应温度60℃,产率81%,纯度98%左右。

2-甲氧基亚氨基-2-[(2-四氢吡喃)-2-氧基-苯基]-乙酸甲酯的合成

邻羟基苯乙酸与甲醇在对甲苯磺酸催化下生成邻羟基苯乙酸甲酯,其酚羟基用3,4-二氢吡喃保护生成2-四氢吡喃氧基-苯基-乙酸甲酯,最后与亚硝酸叔丁酯和碘甲烷反应得到2-甲氧基亚氨基-2-[(2-四氢吡喃)-2-氧基-苯基]-乙酸甲酯.该路线反应条件温和,操作简单,收率较高,适合工业化生产.三步反应总收率为63.4%,产品含量为97.9%,其结构经红外和核磁氢谱分析确证.

3,4-二羟基苯乙酸甲酯对肠道病毒71型在人横纹肌肉瘤细胞中复制的抑制

肠道病毒71型（enterovirus71，EV71）属于小RNA病毒科（Picrornaviridae）肠道病毒属（Enterovirus，EV），是手足口病的主要病原体。手足口病至今己在世界各地爆发流行，在亚洲国家流行更为严重。儿童感染EV71可引起发热、口腔黏膜溃疡性疱疹和四肢末端水疱样皮疹，

羟基酪醇的合成

以3,4-二甲氧基苯乙酸为起始原料,制得3,4-二羟基苯乙酸,3,4-二羟基苯乙酸再在SOCl2存在下与甲醇反应制得3,4-二羟基苯乙酸甲酯,以Bouveault-Blanc反应为基本原理,通过钠/乙醇还原3,4-二羟基苯乙酸甲酯制得羟基酪醇,并通过1HNMR、IR、MS等方法对其进行了表征。该文还对影响羟基酪醇收率的原料配比、反应时间、反应温度以及钠/乙醇还原3,4-二羟基苯乙酸甲酯反应的机理进行了研究和探讨。

波谱解析教学中MestReNova和ChemDraw软件的应用

核磁共振氢谱和碳谱已经发展成为有机化合物结构鉴定的核心手段,也是本科生《波谱解析》课程中的教学重点和难点。本文以对羟基苯乙酸甲酯为例,介绍MestReNova和ChemDraw软件在核磁共振教学过程中的应用。通过对波谱解析相关软件的学习和应用,进一步加深学生对化学位移、偶合常数及自旋裂分与化学结构之间关系的认识,从而提高学生的学习兴趣和积极性,同时也培养了学生分析问题和解决问题的能力。

3-[α-甲氧基亚氨基-α-(2-羟基苯基)-甲基]-5,6-二氢-1,4,2-二噁嗪的合成

[目的]3-[α-甲氧基亚氨基-α-(2-羟基苯基)-甲基]-5,6-二氢-1,4,2-二噁嗪是甲氧基丙烯酸酯类杀菌剂的一个重要中间体。[方法]以邻羟基苯乙酸甲酯为原料,经羟基保护、肟化、甲基化、环合、脱保护合成3-[α-甲氧基亚氨基-α-(2-羟基苯基)-甲基]-5,6-二氢-1,4,2-二噁嗪。[结果]在优化的反应条件下,反应总收率为27.0%(以邻羟基苯乙酸甲酯计),含量为98.5%,其结构经1H NMR和红外分析确认。[结论]该工艺简单经济,条件温和,适合工业化生产。

美托洛尔的合成工艺研究

本文以价廉易得的对羟基苯乙酸甲酯为原料,通过酚羟基苄基保护、酯键还原、甲基化、脱苄基得到关键中间体对甲氧基乙基苯酚5,再与环氧氯丙烷发生烷基化反应,最后与异丙胺反应开环得到美托洛尔。对于合成路线中的关键步骤进行了工艺优化,分步平均收率高达89.3%,6步反应总收率也高达48%。中间体及目标化合物均通过~1HNMR和^(13)CNMR确证了结构。该方法具有原料易得、合成步骤短、收率高以及易于工业化制备等优点。

Grafting of 2-Hydroxyethyl Methacrylate onto Silk by Atom Transfer Radical Polymerization

Silk was grafted using 2-hydroxyethyl methacrylate(HEMA)by atom transfer radical polymerization(ATRP)method.The amino groups and hydroxyl groups on the side chains of the silk fibroin was reacted with 2-bromoisobutyryl bromide(BriB-Br)to obtain efficient macroinitiator for ATRP.And the macroinitiator was grafted with HEMA in water aqueous using CuBr/N,N,N',N",N"-pentamethyldiethylenetriamine(PMDETA)as catalyst system.The effects of monomer concentration,the proportion of CuBr and PMDETA,grafting temperature and time on the silk grafting were discussed,and the optimal grafting technology was obtained.FT-IR characterization of the grafted silk showed a peak corresponding to HEMA,which indicated that HEMA was grafted onto the surface of silk.ATRP method could be applied on the silk modification and this technique provided a new way for silk grafting.

Study on Synthesis and Chloramphenicol Release of Poly（2-hydroxyethylmethacrylate-co-acrylamide） Hydrogels

In this article, poly（2-hydroxyethylmethacrylate-co-acrylamide） hydrogels were synthesized by bulk free-radical copolymerization of 2-hydroxyethylmethacrylate （HEMA） and acrylamide （AAm） for soft contact lens（SCL）-based ophthalmic drug delivery system. The copolymer was characterized with FT-IR and SEM, the swelling property of the hydrogels were studied by gravimetrical method, and chloramphenicol was used as a model drug to investigate drug release profile of the hydrogels. The results showed that poly（2-hydroxyethylmethacrylateco-acrylamide） hydrogels were transparent and useful SCL biomaterial, the water content increased as AAm content increase and pH decrease, and in the same way, hydrogel composition affected chloramphenicol release process too. Migration rate of chloramphenicol increased as the AAm content in the hydrogels increased in the first stage of diffusion process, whereas there was no significant difference thereafter.

Porous alumina ceramic via gelcasting based on2-hydroxyethyl methacrylate dissolved in tert-butyl alcohol

To obtain porous alumina ceramic with high strength,a novel gelcasting system based on 2-hydroxyethyl methacrylate(HEMA)dissolved in tert-butyl alcohol(TBA)was developed.The polymerization of the HEMA-TBA gelcasting system,the thermal behavior of obtained green body,and the microstructures and mechanical properties of the sintered bodies were investigated by rheometer,TG-DSC,SEM and bending strength testing,respectively.The results show that,(1)10 mg/mL of the initiator(benzoyl peroxide)is the optimal amount for polymerization of this gelscasting system at 25 ℃;(2)The alumina suspension of the HEMA-TBA gelcasting system showing shear-thinning behavior is sufficiently low for gelcasting process;(3)The bending strength of porous alumina ceramic samples,whose porosities range from 42% to 56%,is from(8±0.5)to(91±4.5)MPa.

HIGH SOLIDS-CONTENT NANOSIZE POLYMER LATEXES MADE BY A MODIFIED EMULSION COPOLYMERIZATION

Polymer nanoparticles were prepared in the methyl methacrylate (MMA)/buty lmethacrylate (BA) emulsion copolymerization process by a modified microemulsion copolymerization method. 2-Hydroxyethyl methacrylate(HEMA), acrylate (AA) and methyl acrylate (MAA) were used as reactive cosurfactants. With this process high polymer: surfactant weight ratios (40:1 or greater),relatively concentrated (~30wt. %) latexes and small (~60nm) particle diameters were obtained.Properties of the latexes were characterized by TEM, DSC, dynamic light scattering, and IR spectroscopy.

青龙衣抗肿瘤有效部位的化学成分研究

目的研究抗肿瘤中药青龙衣（核桃楸Juglans mandshurica未成熟的外果皮）的化学成分。方法采用溶剂萃取,反复硅胶柱色谱、Sephadex LH-20柱色谱、高效液相制备色谱等方法对青龙衣抗肿瘤活性部位即氯仿和醋酸乙酯萃取部位进行分离提纯。依据主要理化性质和波谱数据鉴定化合物的结构。结果从青龙衣抗肿瘤活性部位中分离鉴定了13个化合物,分别为4（R）-乙氧基-8-羟基-α-四氢萘醌（1）、4（R）-核桃酮（2）、没食子酸乙酯（3）、对羟基苯乙酸甲酯（4）、8-羟基蒽醌-1-羧酸（5）、4（R）,5-二羟基-α-四氢萘酮（6）、杨梅醇（7）、胡桃宁B（8）、5-去氧杨梅酮（9）、5-羟基-1-（4′-羟苯基）-7-（4″-羟基-3″-甲氧基）-3-庚酮（10）、6,5′-二异戊烯基槲皮素（11）、山柰酚-3-O-α-L-鼠李糖苷（12）、槲皮素-3-O-α-L-鼠李糖苷（13）。结论化合物3～5,7,9～13为首次从青龙衣中分离得到,首次从胡桃属植物中分离得到了异戊烯基取代黄酮。

Preparation of a pH-sensitive pantoprazole-imprinted polymer and evaluation of its drug-binding and-releasing properties

The aim of this work was to synthesize a pantoprazole-imprinted polymer(MIPs)and study its binding and release properties in an aqueous media.Methacrylic acid(MAA),methacrylamide(MAAM),hydroxyethyl methacrylate(HEMA),and 4-vinyl pyridine(4VP)were tested as functional monomers.Different solvents were also applied as polymerization media under heat or UV radiation.The optimized MIP was prepared in chloroform as a solvent,4-vinyl pyridine as a functional monomer,and ethylene glycole dimethacrylate(EGDMA)as a crosslinker monomer under UV irradiation.Binding and release properties of MIP were studied in comparison with a non-imprinted polymer(NIP)in aqueous media,at different pH values.The protective effect of polymer for drugs against acidic conditions was evaluated at pH 2.Results indicated that the MIP had superior binding properties compared to NIP for pantoprazole.The percentage of drug released from MIP was significantly less than from NIP at all pH values,which was attributed to the presence of imprinted cavities in the MIP matrix.MIP also had a stronger protective effect for pantoprazole in acidic media,in comparison with NIP.

States of Water in Hydrogels Containing with Glyceryl Methacrylate

Hydrogel materials were prepared by thermopolymerization with different content of glyceryl methacrylate and hydroxyethyl methacrylate. The different states of water in swelling hydrogels were described and studied by differential scanning calorimetry(DSC). It was found that the hydrophilicity of GMA was stronger than HEMA,the water content and bound water of GMA hydrogel are higher than HEMA hydrogel.With the increase of GMA content, the content of free water in hydrogel increased. When GMA content was lower than 50%, the increase of GMA content also increased the content of bound water; but when GMA content was higher than 50%, the increase of GMA content decreased the content of bound water, which was caused by the chain hydrogen bond formed on the GMA chain with hydroxyl group each other.