2,6-二取代苯乙酮苯腙在多聚磷酸(PPA)存在下的成环反应

Fischer反应是合成吲哚最常用的方法之一。我们用2,4,6-三甲氧基苯乙酮苯腙在PPA存在下成环时,只得到了少量的的2-(2,4,6-三甲氧基苯基)吲哚,而主要产物则为4,6-二甲氧基-3一甲基-1-苯基吲唑。为了进一步研究在PPA存在下的Fischer     

2,6-二取代苯乙酮苯脘在多聚磷酸(PPA)存在下的成环反应

本文用2,4,6-三甲氧基苯乙酮苯腙在多聚磷酸(PPA)存在下成环时, 得到了少量的2-(2,4,6-三甲氧基苯基)吲哚, 而主要产物则为4,6-二甲氧基-3-甲基-1-1苯基吲唑。     

2-取代吲哚的染料敏化光氧化反应

2-苯基吲哚 (1a) 在甲醇中的染料敏化光氧化反应给出2-苯基-2-(2'-苯基-3'-吲哚基)二氢吲哚-3-酮 (2a) 和2-甲氧基-2-苯基二氢吲哚-3-酮 (4a), 相应N-甲基取代产物由1-甲基-2-苯基吲哚 (1b) 的类似反应获得。发现反应产物分布随吲哚 (1) 的浓度和介质酸度的变化而变化。对反应机理进行了推测, 其中当1a的反应在乙腈中进行时, 分离到了相应的反应中间体: 2-苯基-3H-吲哚-3-酮 (3a)。     

2-芳基吲哚的敏化光氧化偶合反应

本文研究了十七种2-芳基吲哚(1a-1q)在甲醇-乙酸介质中的亚甲基蓝(MB)敏化光氧化反应, 发现有十五种吲哚(1a-1o)以85%-95%的产率给出2,2'-二芳基-[2,3'-联-1H-吲哚]-3(2H)-酮(2a-2o), 而2-(4-硝基苯基]吲哚(1p)和2-联苯基吲哚(1q)则分别生成2-甲氧基-2-(4-硝基苯基)-1,2-二氢-3H-吲哚-3-酮(7p)和2-联苯基-4H-3,1-苯并恶嗪-4-酮(11q), 其中7p在分离过程中失去甲醇分子给出2-(4-硝基苯基)-3H-吲哚-3-酮(10p)。     

6-(4-取代苯乙烯基)-8-(4-取代苯基)-10,10-二甲基-10H-吡啶并[1,2-a]吲哚盐的合成

通过2,3,3-三甲基-3H-吲哚高氯酸盐与取代双亚苄基丙酮在异戊醇中的反应,合成五种新的6-(4-取代苯乙烯基)-8-(4-取代苯基)-10,10-二甲基-10H-吡啶并[1,2-a]吲哚盐[R=H(3a),Cl(3b),Br(3c),MeO(3d),Me_2N(3e)]。     

8-(4-取代苯基)-10,10-二甲基-6-苯基-10 H-吡啶并[1,2-a]吲哚盐的合成

2,3,3-三甲基-3H-吲哚高氯酸盐与取代查耳酮在异戊醇中反应,得到五种新的8-(4-取代苯基)-10,10-二甲基-6-苯基-10 H-吡啶并[1,2-a]吲哚盐[R=Me_2N-(3a),R=MeO-(3b);R=Br-(3c),R=H-(3d);R=O_2N-(3e)]通过元素分析和光谱测定确证了产物的结构。紫外光谱表明,λ_(max)与R有关,其次序为Me_2N—>MeO—>Br—>H—>O_2N—     

吡啶并吲哚盐的结构及波谱中的取代基效应

前文报道了2,3,3-三甲基-3 H-吲哚高氯酸盐(1)与1.5-二(4-取代苯基)-1,4-戊二烯-3-酮在异戊醇介质中反应,合成了6-(4-取代苯乙烯基)-8-(4-取代苯基)-10,10-二甲基-10 H-吡啶并[1,2-a]吲哚高氯酸盐(4a～g,其中取代基为苯基和硝基的未见报道),但产物     

水中3-甲基-6-氨基-5-氰基-4-芳基-1-苯基-1，4-二氢吡喃[2，3-c]吡唑的洁净合成

在水溶剂中并有三乙基苄基氯化铵（TEBA）存在下，取代芳亚甲基丙二腈与3- 甲基-1-苯基-2-吡唑啉-5-酮缩合成为3-甲基-6-氨基-5-氰基-4-芳基-1-苯基-1， 4-二氢吡喃[2,3-c]吡唑，此法为相应化合物的合成提供了一种快速、方便、高效 和洁净的方法。     

2-苯甲酰基嘧啶类化合物的合成与生物活性

2-嘧啶氧基-N-芳基苄胺类化合物结构经过两次骨架结构优化后得到2-苯甲酰基嘧啶类化合物二次先导结构.在二次先导结构基础上,共设计并合成了36个化合物,所有化合物结构经1H NMR、13C NMR、HRMS确认,并进行了室内杀菌活性筛选,对各部位取代基进行了逐次优化.结果表明2-苯甲酰基嘧啶类化合物中R1取代基以2位卤素或烷基取代的苯环或杂环活性最好;中间苯环6位引入氟原子活性保持;嘧啶环4,6位甲氧基取代活性较好,5位甲基取代活性大大降低;羰基被还原为羟基后活性消失.其中2,3-二氯-N-[2-(4,6-二甲氧基嘧啶-2-甲酰基)苯氧基]-N-甲基苯甲酰胺(4AHl)、2,5-二氯-N-[2-(4,6-二甲氧基嘧啶-2-甲酰基)苯氧基]-N-甲基苯甲酰胺(4AHn)及N-[2-(4,6-二甲氧基嘧啶-2-甲酰基)-3-氟苯氧基]-N,2-二甲基苯甲酰胺(4AFd)对黄瓜白粉病的杀菌活性与对照样苯菌酮相当.     

微管蛋白聚合抑制剂OXi8006的合成新方法

2-(3'-羟基-4'-甲氧基苯基)-3-(3",4",5"-三甲氧基苯甲酰基)-6-甲氧基吲哚(OXi8006)能够有效抑制微管蛋白聚合,而表现出良好抗癌活性.目前报道的OXi8006全合成路线较长、总收率低,且反应条件苛刻.为了更高效地合成该化合物,从而为进一步的活性和构效关系研究提供原料.以廉价易得的异香兰素为起始原料,先合成芳基乙炔,再与3,4,5-三甲氧基苯甲醛通过亲核加成、氧化反应获得二芳基炔酮、二芳基炔酮再与邻碘代苯胺通过杂迈克尔加成和分子内Heck反应构建出OXi8006的主体结构——2-芳基-3-芳酰基取代吲哚,从而缩短了合成路线,并使总收率提高到20%.     

Synthesis and structure of tetra- and triphenylantimony 2,4,6-trichlorophenoxides

The reaction of pentaphenylantimony with 2,4,6-trichlorophenol or bis(2,4,6-trichlorophenoxy)- triphenylantimony in toluene afforded (2,4,6-trichlorophenoxy)tetraphenylantimony. The reaction of triphenylantimony with tert-butyl hydroperoxide and 2,4,6-trichlorophenol led to the formation of bis(2,4,6-trichlorophenoxy) triphenylantimony; further reaction of the latter with triphenylantimony dichloride provided (2,4,6-trichlorophenoxy)triphenylantimony chloride. According to the XRD data, the antimony atoms in the prepared compounds had distorted trigonal-bipyramidal coordination with electronegative ligands in axial positions.     

Reaction of thiopyrylium ion with active methylene compounds

The reaction of 2,4,6-triphenylthiopyrylium ion with several active methylene compounds in the presence of base has been found to yield 2,4,6-triphenylbenzene derivatives. In the case of the reaction of 2,4,6-triphenylthiopyrylium fluoroborate with nitromethane, an alkali treatment gave 2,4,6-triphenylnitrobenzene, and an acid treatment afforded 2,4,6-triphenylbenzene, respectively. From these results, the reaction behaviour of the thiopyrylium ion has been discussed.     

Reactivity of halophenol and formation of phenoxo–copper(II) complex in basic copper-catalyzed halogen displacement polymerization

The halogen displacement polymerization of 2,4,6-trihalophenol with heterogeneous basic copper(II) complex is described. The corresponding poly(dihalophenylene oxides) have been obtained from 2,4,6-trichloro-, 2,4,6-tribromo-, and 2,4,6-triiodophenol with the present catalytic system. In the halophenols used, the order of reactivity was as follows; 2,4,6-trichloro- < 2,4,6-tribromo- < 2,4,6-triiodophenol. With 2,4,6-trichlorophenol as a monomer, the 2,4,6-trichlorophenoxo–copper(II) complex, which had the composition Cu(OCH₃)(C₆H₂Cl₃O) and was considered to be a reaction intermediate, was isolated. The ESR spectrum of this complex at room temperature showed a sharp peak considered to be free organic radical, in addition to the broad one based on copper(II) ion. Poly(dichlorophenylene oxide) was obtained by thermal decomposition of the phenoxo–copper(II) complex. It was concluded that the formation and decomposition of the phenoxo–copper(II) complex were intermediate steps of halogen displacement polymerization of 2,4,6-trihalogenophenol with heterogeneous basic copper(II) catalyst.     

Reaction of 2,4,6-substituted pyrylium salts with compounds containing a C = N bond

2,4,6-Substituted pyrylium salts add azomethines to give pyridinium salts and aromatic aldehydes. The latter can be condensed with the methyl groups of the pyridinium salts. Benzaldoxime, benzalazine, benzalphenylhydrazine, urea, thiourea, and phenyl isothiocyanate react with 2,4,6-triphenylpyrylium perchlorate similarly to give, respectively, 2,4,6-triphenylpyridine N-oxide, 2,4,6-triphenylpyridine, or N-substituted 2,4,6-triphenylpyridinium perchlorates.     

水溶液中2,4,6-三溴苯酚在银阴极上的选择性脱卤

采用循环伏安法比较了玻碳、光亮银和粗糙化银电极对2,4,6-三溴苯酚还原脱卤反应的电催化活性, 初步研究了碱性水溶液中2,4,6-三溴苯酚在粗糙化银电极上的还原脱卤历程; 在此基础上, 利用恒电位电解法进一步探索了2,4,6-三溴苯酚在粗糙化银电极上的电还原脱卤历程. 结果表明, 粗糙化银电极对2,4,6-三溴苯酚的选择性还原脱卤反应具有优良的电催化活性, 且其活性优于光亮银和玻碳电极; 2,4,6-三溴苯酚在粗糙化银电极上的还原反应是个逐步脱卤过程, 推测得出其邻位和对位C—Br键的还原断裂所需的活化能非常接近, 而反应中间产物2,4-二溴苯酚的对位C—Br键的还原断裂所需的活化能比邻位要低; 2,4,6-三溴苯酚能实现完全脱卤生成苯酚, 主要路径为2,4,6-三溴苯酚→2,4-二溴苯酚→2-溴苯酚→苯酚.     

Regioselective synthesis of 2,4,6-triaminopyridines

A regioselective synthesis of 2,4,6-trisubstituted pyridine is described starting from 2,6-dibromo-4-nitropyridine. All three different regioisomers of the 2,4,6-triamino substituted pyridine have been synthesized in four to five steps. The method described is a general route to unsymmetrical 2,4,6-trisubstituted amino pyridines.     

A convenient synthetic route to 2,4,6-tris(chlorosulfonyl)- and 2,4,6-tris(fluorosulfonyl)phenol, aniline and chlorobenzene

Convenient and preparative synthetic procedures of 2,4,6-tris(chlorosulfonyl)- and 2,4,6-tris(fluorosulfonyl)phenol, -chlorobenzene and -aniline have been elaborated. Chlorine exchange for fluorine by KF interaction on 2,4,6-tris(chlorosulfonyl)aniline and especially 2,4,6-tris(chlorosulfonyl)phenol proceeds easily and selectively under anhydrous conditions in dioxane. Unlike, 2,4,6-tris(chlorosulfonyl)chlorobenzene transformation requires the presence of water. On the basis of 2,4,6-tris(fluorosulfonyl)phenol and some of its salts, XRD measurements demonstrated the structural similarity to picric acid and its derivatives in the solid state.     

Synthesis of phosphorus ylides bearing a P-H bond from a kinetically stabilized 1,3,6-triphosphafulvene

In mixing 2,4,6-tris(2,4,6-tri-tert-butylphenyl)-1,3,6-triphosphafulvene with alkyllithium compounds and acetic acid, both of nucleophilic alkylation and electrophilic protonation occurred at the exo sp2-phosphorus atoms to afford [2,4-bis(2,4,6-tri-tert-butylphenyl)-1,3-diphosphacyclopentadienylidene](alkyl)(2,4,6-tri-tert-butylphenyl)phosphoranes which are phosphorus ylides that bear a P-H bond. A phosphorus ylide bearing both P-H and P-F bonds was obtained by reaction of 2,4,6-tris(2,4,6-tri-tert-butylphenyl)-1,3,6-triphosphafulvene with hydrogen tetrafluoroborate, and the structure was determined by X-ray crystallography. Both P=C double bond and P(+)-C(-) zwitterionic character was indicated by the metric parameters. The isolated phosphorus ylide bearing a P-H bond, [2,4-bis(2,4,6-tri-tert-butylphenyl)-1,3-diphosphacyclopentadienylidene](2,4,6-tri-tert-butylphenyl)phosphorane, showed no isomerization by H-migration to the corresponding phosphinodiphospholes, probably due to the pi-accepting ability of the unsaturated PC bonds and aromaticity of the C3P2 ring. The ylide structure and aromaticity of 2,4-diphosphacyclopenta-2,4-dienylidenephosphorane was characterized by theoretical calculations. In addition, the regioselective protonation of the lithiated phosphinodiphospholes generated from the 1,3,6-triphosphafulvene is discussed.     

顶空固相微萃取气相色谱法测定浓海水中的氯酚

建立浓海水中氯酚的顶空固相微萃取气相色谱法检测方法。采用顶空固相微萃取对海水淡化排放的浓海水样品中2,4,6-三氯酚(2,4,6-TCP)和五氯酚(PCP)进行分离富集,气相色谱-电子捕获检测器(μECD)测定浓海水样品中2,4,6-TCP和PCP的含量。讨论了萃取时间、萃取温度、水样盐度等实验条件对富集效率的影响,确定了萃取时间为40 min,萃取温度为60℃。2,4,6-TCP,PCP的质量浓度在0.500~20.0μg/L范围内与其色谱峰面积呈良好的线性关系,线性相关系数均大于0.999,2,4,6-TCP和PCP的检出限(2S/N)分别为0.055,0.128μg/L,测定结果的相对标准偏差为3.65%~11.4%(n=6),加标回收率为73.5%~119.0%。该方法快速,灵敏度高,适合于浓海水中氯酚的分析。     

Sensitive and Selective Determination of 2,4,6-Trichlorophenol Using a Molecularly Imprinted Polymer Based on Zinc Oxide Quantum Dots

Novel core-shell molecularly imprinted polymers were prepared based on zinc oxide quantum dots for the determination of 2,4,6-trichlorophenol by fluorescence. Principally, ZnO quantum dots and 2,4,6-trichlorophenol were chosen as the core substrate and the template molecule, respectively. The specific recognition sites for 2,4,6-trichlorophenol were obtained during the polymerization process in presence of 3-aminopropyltriethoxysilane and tetraethylorthosilicate. Molecularly imprinted ZnO quantum dots were characterized by transmission electron microscopy and Fourier transform infrared spectroscopy and the optical properties were evaluated by spectrofluorometry. Under the optimal conditions, molecularly imprinted ZnO quantum dots were successfully applied to the sensitive determination and selective recognition of 2,4,6-trichlorophenol in water. A linear relationship was obtained to cover the concentration range of 0–160?µmol?L^?1 with a correlation coefficient of 0.9931 calculated by the Stern–Volmer equation. The products were used for the determination of 2,4,6-trichlorophenol in the water from local rural areas and the results strongly supported that the molecularly imprinted ZnO quantum dots were suitable for the determination of 2,4,6-trichlorophenol in real examples.