2,4-二氟苯硼酸的合成工艺研究与表征

以2,4-二氟溴苯、正丁基锂、硼酸三丁酯为原料合成了2,4-二氟苯硼酸,产率84.5%,产物经液相、核磁、元素、红外进行分析和表征。考察了硼化试剂、投料摩尔比、反应温度、反应时间对产率的影响,优化工艺条件为:以硼酸三丁酯为硼化试剂,n(2,4-二氟溴苯):n(正丁基锂):n(硼酸三丁酯)=1:1.2:2,反应温度为-78℃,反应时间为5h。     

3-氟-4-氯苯硼酸的合成工艺优化

以2-氯-5-溴苯胺为起始原料,经重氮化反应得到2-氯-5-溴氟苯,再与乙基溴化镁进行格式交换后与硼酸三甲酯作用,水解得到3-氟-4-氯苯硼酸。实验过程中将格式试剂法、三丁基锂法与格氏试剂交换法作对比,并对格氏试剂交换法的过程条件如硼化试剂、反应温度、反应原料配比进行了优化,在最优条件下总收率约60%,纯度99%。此过程采用的是较温和的格氏试剂交换法,无需用到超低温等较苛刻的条件,适于工业放大生产。     

2,2-二氟-1,3-苯二氧戊环-4-甲醛的合成

标题化合物是合成杀菌剂咯菌腈的重要原料,考察了以邻香兰醛为原料制备2,3-二羟基苯甲醛,然后与二氟二氯甲烷反应直接合成得到目标中间体的方法。通过优化反应条件,得到最佳反应条件为0.5 mol/L双氧水、3.5 mol/L氢氧化钠、反应温度为60℃,水解得2,3-二羟基苯甲醛。再以DMSO为反应溶剂,3.0 mol/L二氟二氯甲烷在80℃下通过环合反应得到标题化合物,总收率为75%,纯度为97%。     

合成侧向含氟酯类液晶的新方法

在-80℃条件下,以3 氟丙基苯为原料,通过与丁基锂、硼酸三甲酯和过氧化氢反应,新路线制备了中间体2 氟 4 丙基苯酚收率为76%(老方法收率为15%)。通过酯化合成了液晶化合物反式 4′ (4″ 丙基环己基)环己基甲酸2 氟 4 丙基苯酚酯,两步总收率为62%。目标化合物经IR,1HNMR,MS和元素分析确认了分子结构,液晶的相变温度通过差热扫描仪测定。     

3,4,5-三氟-2-甲基苯类液晶化合物的合成与性能

以3,4,5-三氟苯酚、3,5-二氟-4'-烷基联苯为原料,经酚羟基保护反应、丁基锂/碘甲烷上甲基反应、Williamson醚化反应等5步反应最终合成4-[二氟(3,4,5-三氟-2-甲基-苯氧基)甲基]-3,5-二氟-4'-烷基联苯类化合物。纯化后目标产物的气相色谱纯度≥99.5%,总收率约为47%,结构经~1HNMR及GC-MS确证。其中,合成2-(3,4,5-三氟-2-甲基-苯氧基)四氢吡喃适宜的物质的量比为n(2-(3,4,5-三氟苯氧基)四氢吡喃)∶n(丁基锂)=1∶1.2,3,4,5-三氟-2-甲基苯酚和4-溴二氟甲基-3,5-二氟-4'-烷基联苯醚化反应的最优化条件为在DMSO中反应4 h。将该化合物添加到液晶的基础配方中,能降低旋转粘度(γ1),提高液晶的响应速度,增加介电各向异性(Δε),降低阈值电压。     

N-(2-氟-5-苯硼酸频哪醇酯)-2-吗啉代乙酰胺合成研究

介绍了N-(2-氟-5-苯硼酸频哪醇酯)-2-吗啉代乙酰胺的合成方法。以2-氟-5-溴苯胺为起始原料、先与联硼酸频哪醇酯反应,得到中间体3-氨基-4-氟苯硼酸频哪醇酯,在经过两步反应,得到所要的目标化合物。结果表明:该合成路线目标化合物的总收率为71.7%,其化学结构经MS、1H-NMR经行了确证。该合成工艺具有操作简单,原料易得,后处理方便,总收率较高,适合工业化生产。     

杀菌剂氟嘧菌酯的合成

报道了杀菌剂氟嘧菌酯的合成工艺研究。以4-羟基香豆素为原料,依次经过硝化、碱水解、甲胺化、环合、醚化和碱重排环合反应得到(E)-(5,6-二氢-[1,4,2]-二嗪-3-基)-(2-羟基苯基)-甲酮-O-甲基肟(中间体F);以2-氟丙二酸二乙酯为原料,经与醋酸甲脒成环后进行氯化反应合成中间体4,6-二氯-5-氟嘧啶;中间体F先后与4,6-二氯-5-氟嘧啶和2-氯苯酚进行醚化反应得到目标产物氟嘧菌酯。以4-羟基香豆素计,合成总收率达17%,产品质量分数为96%(HPLC)。     

氟嘧菌酯的清洁合成工艺

[目的]对氟嘧菌酯合成工艺进行清洁化研究。[方法]开发了以4,6-二羟基-5-氟嘧啶为原料,硫酰氟为氟化试剂,“一步法”合成4,5,6-三氟嘧啶的新工艺。4,5,6-三氟嘧啶再与邻氯苯酚和3-[1-(2-羟基苯基)-1-(甲氧亚氨基)-甲基]-5,6-二氢-1,4,2-二嗪经2步醚化反应合成了氟嘧菌酯。[结果]3步反应总收率70.6%,避免了含磷废水排放,并副产氟化钠和氯化钾。[结论]工艺过程清洁、绿色环保、成本低廉,适合工业化生产。     

4-乙氧基-2,3-二氟苯乙酮的合成与表征

以2,3-二氟苯乙醚和乙酰氯为起始原料,经傅克反应合成了质量分数99%以上的液晶中间体4-乙氧基-2,3-二氟苯乙酮,对目标化合物进行了1HNMR、IR和GC-MS表征。以二氯甲烷为反应溶剂,当n(2,3-二氟苯乙醚)∶n(三氯化铝)∶n(乙酰氯)=1∶1.14∶1.3,反应温度为-10～-5℃,反应时间为1 h时,反应效果最佳,产物质量分数为89.2%,2,3-二氟苯乙醚质量分数为4.83%,副产物4-乙酰基-2,3-二氟苯酚醋酸酯质量分数为0.12%,产物异构体未检出。根据实验结果对傅克反应副产物产生的原因进行了推测。     

4,5-二氟-2-羟基苯丁酮的合成及生物活性测定

[目的]合成4,5-二氟-2-羟基苯丁酮并测其农用生物活性。[方法]以3,4-二氟苯酚为原料,与乙酰氯反应成酯以保护酚羟基、以丁酰氯为酰化剂进行傅-克酰基化反应、脱保护得目标产物;以菌丝生长速率法测抑菌活性;以琼脂混药法测除草活性。[结果]产物的1H NMR及质谱分析与目标化合物一致;以无水三氯化铝为催化剂,实施丁酰化过程中可直接得到目标化合物,反应的总收率为67.07%;对苹果腐烂病菌、白菜灰霉病菌、柑橘炭疽病菌的EC50值分别为74.37、100.18、102.77 mg/L;质量浓度为200 mg/L时,对生菜、稗草、反枝苋的根与茎的抑制率均达到60%以上。[结论]以3,4-二氟苯酚为原料进行酚羟基酯化保护,然后以无水三氯化铝为催化剂与正丁酰氯反应不需另外的脱保护过程来制备4,5-二氟-2-羟基苯丁酮是一条高效路线;目标化合物具有较好的抑菌和除草活性。     

1-甲基-1H-吡唑-5-硼酸频哪醇酯的合成

以1H-吡唑为原料,经磷酸三甲酯甲基化,正丁基锂锂化后与硼酸三甲酯硼酸化,再与频哪醇缩合得到1-甲基1H-吡唑-5-硼酸频哪醇酯,3步反应的总收率为27.4%。优化了中间体3的合成和纯化。目标化合物经1H NMR结构确证。     

邻溴苯硼酸的合成研究

以邻溴苯胺为原料通过重氮化,碘代反应合成了邻溴碘苯,收率83%（HPLC纯度99.5%）;然后再与异丙基溴化镁反应生成邻溴苯基溴化镁,再与硼酸三甲酯进行亲核取代、水解生成邻溴苯硼酸,收率59.3%（HPLC纯度99.6%）。     

Schlesinger法合成硼氢化钠工艺条件及优化途径

目前工业化合成硼氢化钠的工艺有Schlesinger法和Bayer法,而Schlesinger法是工业化合成硼氢化钠应用最广的工艺,其关键步骤为氢化钠和硼酸三甲酯的合成。本文一方面从氢化钠的合成、硼酸三甲酯的合成及硼氢化钠的合成3个方面详细论述了Schlesinger法合成工艺进展情况;并指出目前方法存在的问题,如采用油液分散金属钠法合成的氢化钠活性差,制约了氢化钠的应用,硼酸三甲酯工业合成过程中过多使用浓硫酸造成环境严重污染。另一方面对Schlesinger法工艺改进提出了几点设想,如企业全流程合成硼氢化钠可节约外购成本和仓储成本;硼酸三甲酯的合成取代浓硫酸的应用,提纯采用盐析的方法均可以减轻环境污染;硼氢化钠水解过程中采用稀液碱溶液代替淡水,可避免硼氢化钠水解,提高产品收率。     

Separation of Trimethyl Borate from a Liquid Mixture by Pervaporation

Four commercial polyvinyl alcohol (PVA) and polydimethylsiloxane (PDMS) membranes were applied to the pervaporation of an azeotropic mixture containing trimethyl borate, a precursor to boronic acids used in Suzuki couplings and a gaseous anti‐oxidant in solder flux or brazing. The degree of cross‐linking of the chains in the active layer played a crucial role in the membrane process using the membranes PERVAP 4155‐80, PERVAP 4155‐40 and PERVAP 4155‐30. PERVAP 4155‐30 reached the best results from all tested membranes; an impressive selectivity with fast permeation was also achieved with the PERVAP 4060 membrane. Methanol preferentially passed through PERVAP 4155‐30, but trimethyl borate was favorably pervaporated from the mixture by PERVAP 6040, due to the diverse affinities of the membranes.     

硼酸三甲酯-甲醇-氯化锂体系液液平衡的测定

分别采用Othmer法和液液平衡釜法测定了298.15K下硼酸三甲酯-甲醇-氯化锂三元体系的液液平衡数据。实验发现：氯化锂的摩尔分率对硼酸三甲酯在甲醇中的溶解度影响较大。在平衡的酯相和醇相中,当醇相中氯化锂的质量百分数小于12．99％时,醇相的密度小于酯相;当醇相中氯化锂的质量百分数大于14．24％时,醇相的密度大于酯相;酯相中硼酸三甲酯的质量百分数最高达98.8％,而氯化锂仅为0．01％。液液平衡的测定为氯化锂盐析工艺提供基础研究。     

Density functional theory study on LBDOB and its derivatives: Electronic structures, energies, and molecular properties

Theoretical studies on unsymmetrical electrolyte salts, lithium [1,2-benzenediolato(2-)-O,O′ oxalato]borate (LBDOB), and its derivatives, lithium bis[1,2-benzenediolato(2-)-O,O′]borate (LBBB), and lithium bis(oxalate)borate (LBOB) are carried out using density functional theory (DFT) method and B3LYP theory level. Bidentate structures involving two oxygen atoms are preferred. Based on these conformations, a linear correlation was observed between the highest occupied molecular orbital (HOMO) energies and the limiting oxidation potentials measured by linear sweep voltammetry, which supports experimental results that strongly electron-withdrawing substituent anions are more resistant against oxidation. The correlations were also observed between ionic conductivity and binding energy solubility and theoretical set of parameters of anion, thermal stability and the hardness (η). Wave function analyses have been performed by natural bond orbital (NBO) method to further investigate the cation-anion interactions.     

Electronic structures and molecular properties of FLBDOB and its derivatives: A combined experimental and theoretical study

Theoretical studies on a new unsymmetrical electrolyte salt, lithium [3-fluoro-1,2-benzenediolato(2-)-o,o′ oxalato]borate (FLBDOB), and its derivatives, lithium bis[3-fluoro-1,2-benzenediolato(2-)-o,o]borate (FLBBB), and lithium bis(oxalate)borate (LBOB) are carried out using density functional theory (DFT) method and B3LYP theory level. Bidentate structures involving two oxygen atoms are preferred. Based on these conformations, a linear correlation is observed between the highest occupied molecular orbital (HOMO) energies and the limiting oxidation potentials measured by linear sweep voltammetry, which supports experimental results that strongly electron-withdrawing substituent anions are more resistant against oxidation. The correlations are also observed between ionic conductivity and binding energy, solubility and theoretical set of parameters of anion, thermal stability and the hardness (η). Wave function analyses are performed by natural bond orbital (NBO) method to further investigate the cation-anion interactions.     

Density functional theory study on LDFBDB and its derivatives: Electronic structures, energies, and molecular properties

Theoretical studies on unsymmetrical electrolyte salts, lithium difluoro(1,2-benzene-diolato(2-)-o,o′)borate (LDFBDB), and its derivatives, lithium bis[1,2-benzene-diolato(2-)-O,O′]borate (LBBB) and lithium fluoroborate (LiBF₄) are carried out using density functional theory (DFT) method and B3LYP theory level. Bidentate structures are preferred. Based on these conformations, a linear correlation was observed between adiabatic ionization potential I_p and the limiting oxidation potentials measured by linear sweep voltammetry, which supports experimental results that strongly electron-withdrawing substituent anions are more resistant against oxidation. The correlations were also observed between ionic conductivity and binding energy, solubility and theoretical set of parameters of anion. Wave function analyses have been performed by natural bond orbital (NBO) method to further investigate the cation–anion interactions.     

由α-异佛尔酮催化合成3,5,5-三甲基-1,2-环己二酮的研究

以α-异佛尔酮为原料,经过碱性条件下过氧化氢环氧化和固体酸催化重排合成3,5,5-三甲基-1,2-环己二酮。考察了反应温度、反应时间、反应溶剂对重排反应的影响。优化条件为:以无水氯化锌作催化剂,二氯甲烷作溶剂,回流反应30min,2,3-环氧异佛尔酮于回流温度下可完全转化,产物的选择性达87.4%。