首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
采用一步法合成了5种三联吡啶的衍生物:4′-(吡啶-4-基)-2,2′∶6′,2″-三联吡啶(L1)、4′-苯基-2,2′∶6′,2″-三联吡啶(L2)、4′-(3,5-二氯吡啶-4-基)-2,2′∶6′,2″-三联吡啶(L3)、4′-(3,5-二溴吡啶-4-基)-2,2′∶6′,2″-三联吡啶(L4)、4′-(4-(吡啶-4-基)苯基)-2,2′∶6′,2″-三联吡啶(L5),其中L3和L4为尚未见报道的新颖化合物。以制备的多吡啶化合物为配体,和MnCl2·4H2O共同催化苄基醇的氧化反应,研究发现5种多吡啶配体均具备良好的性能,配体分子结构中的4′-吡啶取代基对提高催化活性有重要作用。最后选用性能最优的4′-(4-(吡啶-4-基)苯基)-2,2′∶6′,2″-三联吡啶为配体,与MnCl2·4H2O共同催化叔丁基过氧化氢氧化苄基醇和苄基烷烃,5种典型底物的转化率均在95%以上,产率在90%以上。该催化氧化方法有望应用于芳香酮类化合物及相关药物中间体的绿色、高效合成。  相似文献   

2.
Cyclonucleophilic addition of N-phthaloylaminoacid chlorides (II on 4-(N-ary-lideneamino)-4′-nitrodiphenyl sulphides (I) in dioxane and triethylamine afforded 4-(4″-aryl-3″-phthalylamino-2″-oxo-azetidin-1″-yl)-4′-nitro-diphenyl sulphides (III). Hydrazinolysis of III yielded 4-(4″-aryl-3″-amino-2″-oxo-azetidin-1″-yl)-4′-nitro-diphenyl sulphide hydrochlorides (IV). Condensation of IV with anisaldehyde using ethanol and piperidine as a basic catalyst gave 4-(4″-aryl-3″-anisylidine amino-2″-oxoazetidin-1″-yl)-4′-nitrodiphenylsulphides (V) in good yields. Interaction of V with chloroacetyl chloride in dioxane and triethylamine produced 4-(4″-aryl-3″-substituted β-lactamyl-2″-oxo-azetidin-1″-yi)-4′-nitrodiphenyl sulphides VI. Oxidation of IV, V and VI using hydrogen peroxide/glacial acetic acid mixtures gave the corresponding sulphones (VII), (VIII) and (IX). Sulphones of the type IX were obtained by unequivocal synthesis through interaction of sulphone-anils VIII with chloroacetyl chloride. The antibacterial activities of some of these compounds were determined.  相似文献   

3.
由克拉霉素的前体6-O-甲基-2′,4″-二(三甲基硅)-红霉素A9-(1-异丙氧基环己基)肟(Ⅰ)出发,常温下以φ(HC l)=10%的盐酸催化水解得3-羟基-6-O-甲基红霉素A9肟(Ⅱ);然后一锅煮进行化合物Ⅱ的2′-羟基乙酰化、3-羟基氧化,得2′-乙酰基-3-氧代-6-O-甲基红霉素A9-(O-乙酰基)肟(Ⅳ);最后脱乙酰基、还原9-肟基再次应用一锅煮法合成,得到目的化合物3-氧代-6-O-甲基红霉素(Ⅵ),总收率为57.0%,经HPLC测定w(Ⅵ)=98.5%。通过1HNMR1、3CNMR和MS,表征了各中间体及目标化合物的结构。  相似文献   

4.
5-Imino-3-methyl-l-phenyl-2-pyrazoline-4-dithiocarbamic acid (I) underwent simultaneous formylation and dimerization reactions with the Vilsmeier reagent giving 4-[5′-imino-3-(1″-formyl-2″-dimethylaminoethenyl)-3′-methyl-1′-phenyl-1′H-pyrazolo-4′-dithiocarbamyl-2,4-dihydro-3-imino-5-methyl-2-phenyl-1-pyrazoline]dithiocarbamate (II) which hydrolysed with sodium hydroxide to give 4-[3′-(1″-formyl-2″-hydroxyethenyl)-3′-methyl-1-phenyl-1′-H-pyrazolo-4′-dithiocarbamyl-1′-pyrazoline]dithiocarbamate-5,5′-dione (IV). Treatment of II and/or IV with morpholine, piperidine, piperazine, hydroxylamine, hydrazine hydrate or phenylhydrazine afforded the corresponding dipyrazolo-4,4′-dithiocarbamate derivatives with different heterocyclic systems at the 3-position. The structures of these compounds were confirmed by microanalysis data, IR and 1H-NMR spectrometry. All synthesized compounds have been screened in vitro against Gram-positive and Gram-negative bacteria, and fungi.  相似文献   

5.
研究龙眼(Dimocarpus longan Lour.)果核的化学成分,采用硅胶柱色谱对龙眼果核石油醚提取物和体积分数95%乙醇提取物进行分离,并利用理化性质和光谱数据鉴定化合物的结构。从龙眼果核的提取物中分离得到一组混合神经酰胺(化合物1、2)和一组混合脑苷脂(化合物3~6),结构鉴定为Rel-(3S,4S,5S)-3-[(2'R)-2'-羟基二十二酰胺]-4-羟基-5-[(4″Z)-十四烷-4″-烯]-2,3,4,5-四氢呋喃(1)、Rel-(3S,4S,5S)-3-[(2'R)-2'-羟基二十四酰胺]-4-羟基-5-[(4″Z)-十四烷-4″-烯]-2,3,4,5-四氢呋喃(2)、1-O-(β-D-吡喃葡萄糖基)-(2S,3S,4R,8E)-2-(2'-羟基二十四酰胺)-8-十八烯-1,3,4-三醇(3)、1-O-(β-D-吡喃葡萄糖基)-(2S,3S,4R,8Z)-2-(2'-羟基二十四酰胺)-8-十八烯-1,3,4-三醇(4)、1-O-(β-D-吡喃葡萄糖基)-(2S,3S,4R,8E)-2-(2'-羟基二十二酰胺)-8-十八烯-1,3,4-三醇(5)、1-O-(β-D-吡喃葡萄糖基)-(2S,3S,4R,8Z)-2-(2'-羟基二十二酰胺)-8-十八烯-1,3,4-三醇(6)。  相似文献   

6.
深入研究了克拉霉素合成中各保护基的脱除反应,发现2′ 和4″ 羟基上的三甲基硅保护基(TMS)和9 肟羟基上的醚化保护基(1 乙氧基环己基)的脱除是分步进行的,温度和pH是影响各个保护基脱除的主要因素。pH=4 6时,常温下反应1h可以脱去两个TMS保护基,而在升温回流的条件下反应0 5h才可以脱去醚化保护基。实验中还发现2′ 和4″ 羟基上的TMS保护基在同一反应条件下对不同的酸的敏感性是不同的。作者分离纯化了脱去各个保护基的反应中间体并进行了结构表征。  相似文献   

7.
A series of new 3,1′-bridged 2-[2′-(4″-dialkylaminophenyl)ethenyl]-4,6-diarylpyrylium perchlorates ( 3 ), 2-[2′-(4″-dialkylaminophenyl)ethenyl]-7-diethylamino-1-benzopyrylium perchlorates 5–8 , 2-[4′-(4″-dialkylaminophenyl)butadien-1′,3″-yl]-, and 2-[2′-(7″-diethylaminocoumar-3″-yl)ethenyl]-7-diethylamino-1-benzopyrylium perchlorates 10–12 were synthesized and characterized by means of elemental analysis, m.p., Vis/NIR, and 1H NMR spectra. Semiempirical MO calculations were performed to elucidate the essential features of the chromophores. The size of the bridging ring strongly affects the geometry of the chromophores which, in turn, determines the extent of charge transfer of the longest wavelength electronic transition. Increasing deviation from planarity causes the polymethine-like chromophore to become more polyene-like.  相似文献   

8.
Synthesis and Polymerization Behaviour of 2-Aryl-5-methylene-1,3-dioxolan-4-ones and Arylbis(5-methylene-1,3-dioxolan-2-yl-4-on)es Starting from 2,6-di(hydroxymethyl)-4-methylphen-ol-Na-salt-1-hydrate ( 1 ) a synthesis of 2-alkoxy-5-methyliso-phthaldialdehydes ( 3a,b ) is described via alkylation and oxidation. Condensation of aromatic aldehydes with 3-bromo-2-hydroxypropanoic acid (β-bromolactic acid) affords diastereoisomeric mixtures of new 2-aryl-5-bromomethyl-1,3-dioxolan-4-ones ( 6a–h ) as well as the corresponding bisdioxolanones ( 6i–l ). Dehydrobromination of 2-aryl-5-bromomethyl-1,3-dioxolan-4-ones ( 6a–d,i ) with DBU leads to 2-aryl-5-methylene-1,3-dioxolan-4-ones ( 8a–e ). Polymerization of compounds 8a , b , d and e proceed via opening of the dioxolanone ring.  相似文献   

9.
Abstract

The synthesis and evaluation of solvent extraction performance of N,N,N′,N′-tetraalkyl-6,6″-(2,2′:6′,2″-terpyridine)diamides and N,N′-diethyl-N,N′-diphenyl-6,6″-(2,2′:6′,2″-terpyridine)diamide are reported here. These new bitopic ligands were found to extract actinides in different oxidation states (U(VI), Np(V and VI), Pu(IV), Am(III), and Cm(III)) from 3 M nitric acid. The presence of three soft nitrogen donors led to the selective extraction of actinides(III) over lanthanides(III) (Ce, Eu) and the presence of two amide functional groups grafted to the terpyridine unit allowed the extraction to occur from a highly acidic medium by minimizing the basicity of the ligand. Ligands bearing long alkyl chains (C4 and C8) or phenyl groups showed increased performances in a polar diluent like nitrobenzene.  相似文献   

10.
Poly[1-methyl-1-[3′-(3″-pyridinyl)propyl]-1-sila-cis-pent-3-ene], poly[1-phenyl-1-[3′-(3″-pyridinyl)propyl)-1-sila-cis-pent-3-ene], and poly[1-phenyl-1-(4′-pyridinyl)-1-sila-cis-pent-3-ene] were synthesized by the anionic ring-opening polymerization of 1-methyl-1-[3′-(3″-pyridinyl)propyl]-1-silacyclopent-3-ene, 1-phenyl-1-[3′-(3″-pyridinyl)propyl]-1-silacyclopent-3-ene, and 1-phenyl-1-(4′-pyridinyl)-1-silacyclopent-3-ene, respectively. These are the first polycarbosilanes which contain heterocyclic pyridine units as side-chain substituents. These polymers were characterized by1H,13C, and29Si NMR as well as by IR and UV spectroscopy. The molecular weight distributions were determined by gel permeation chromatography, glass transition temperatures, by differential seanning calorimetry: (DSC) and thermal behavior, by thermogravimetric analysis. (TGA).  相似文献   

11.
The synthetic details for the construction of three new dipyridotetraazapentalene derivatives, 5H‐pyrido[3″,4″:4′,5′] [1,2,3]triazolo‐ [1′,2′:1,2][1,2,3]triazolo[5,4‐b]pyridin‐6‐ium inner salt ( 8 ), 5H‐pyrido[3″,2″:4′,5′] [1,2,3]triazolo[1′,2′:1,2] [1,2,3]triazolo[5,4‐b]‐pyridin‐6‐ium inner salt ( 15 ) and 5H‐pyrido[2″,3″:4′,5′] [1,2,3]‐triazolo[1′,2′:1,2][1,2,3]triazolo[4,5‐b]pyridin‐6‐ium inner salt ( 16 ) are presented. Nitration of ( 8 ) and ( 15 ) afforded the novel tetranitrodipyridotetraazapentalene derivatives, 2,4,8,10‐tetranitro‐5H‐pyrido[3″,4″:4′,5′][1,2,3]triazolo[1′,2′:1,2][1,2,3]‐triazolo[5,4‐b]‐pyridin‐6‐ium inner salt ( 3 ) and 2,4,8,10‐tetranitro‐5H‐pyrido[3″,2″:4′,5′][1,2,3]triazolo[1′,2′:1,2][1,2,3]‐triazolo[5,4‐b]‐pyridin‐6‐ium inner salt ( 4 ) in good yields. Both isomers, ( 3 ) and ( 4 ), exhibited high thermal stability (differential scanning calorimetric analysis and thermal gravimetric analysis) and were insensitive to impact (hammer/anvil test).  相似文献   

12.
A series of alternate block copolymers of polyphenylene vinylenes that have 1,3-dioctyloxy phenylene in the center of kinked m-terphenyl group as one of the building blocks with either one of the aromatic groups, viz., 1,4-dioctyloxy benzene, 4,6-dioctyloxy benzene and 4,4′-dioctyloxy biphenyl, was synthesized through Heck polymerization. These alternate block copolymers, viz., poly(2,5-bis(octyloxy)phenylene vinylene alt 4′,6′-bis(octyloxy)-1,1′:3′,1″-terphenylene) (P1), poly(2,4-bis(octyloxy)phenylene vinylene alt 4′,6′-bis(octyloxy)-1,1′:3′,1″-terphenylene) (P2) and poly(4,4′-bis(octyloxy-3,3′-biphenylene vinylene alt 4′,6′-bis(octyloxy)-1,1′:3′,1″-terphenylene) (P3), were characterized for their thermal and optical properties. The synthesized polymers had good solubility in organic solvents and were stable up to 350 °C. The molecular weights of the synthesized polymers were in the range 4370–10,900 Da with polydispersity range 1.52–1.65, which were measured by the gel permeation chromatography technique. The optical properties of these polymers showed absorptions in solution at around 400, 329, and 345 nm for P1, P2, and P3 polymers, respectively. The photoluminescence emission maxima of the polymers were at around 461 nm with a shoulder 439 and 424 nm for P1, P2, and P3, respectively. Photoluminescence emission of films of these polymers showed minimum redshift (20 nm) when compared with spectra of their solutions. The optical and photoluminescence emission properties of these polymers were found to vary on the backbone structure.  相似文献   

13.
从克拉霉素的前体 6 O 甲基 2′, 4″ 二 (三甲基硅 ) 红霉素A 9 ( 1 异丙氧基环己基 )肟出发,在φ(C2H5OH) =50%的乙醇水溶液中加入甲酸,加热回流 2h脱去保护得到 6 O 甲基红霉素A9 肟,将它悬浮于水中,在w(HCl) =1%的盐酸水溶液作用下水解去除 3 克拉定糖得到目标化合物 3 羟基 6 O 甲基红霉素A9 肟,它是合成对耐药菌有优良活性的第三代红霉素酮内酯和酰内酯的重要中间体, 收率为 73 3%。为了简化反应步骤,试探了在脱保护一步不分离产物而在w(C2H5OH) =95%的乙醇和w(HCl) =2%的盐酸水溶液反应体系中直接水解脱糖的方法,得到了目标化合物,总收率为 69 0%。通过1HNMR、13CNMR和MR确定了目标化合物的结构。  相似文献   

14.
A viscoelastic window (VW) concept has been proposed to identify different types of pressure-sensitive adhesives (PSA's). Such viscoelastic windows are constructed from the values of dynamic storage modulus: G′ and dynamic loss modulus G″ at frequencies of 10?2 and 102 rad/sec. These frequencies are chosen because the range covers most of the time scales corresponding to the uses of PSA's at different application rates in performance tests. A four quadrant concept has also been recommended to categorize different types of PSA's based on the location of their VW's on the log-log cross plot of G′ and G″. It was found that for most PSA's, the range of G′ and G″ at room temperature within these selected frequencies falls between 103 and 106 Pascals. The proposed four-quadrants (top-left hand quadrant of high G′ and low G″, top-right hand quadrant of high G′ and high G″, lower left hand quadrant of low G′ and low G″, and lower right-hand quadrant of low G′ and high G″) correspond respectively to (1) non-PSA or release coatings (2) high shear PSA's, (3) removable PSA's and medical PSA's and (4) quick and cold stick PSA's. It was also observed that the VW's of general purpose permanent PSA's occupy the central region which straddles part of the four quadrants.  相似文献   

15.
Spin Labeled Oligopeptides as Substrate Analogous Inhibitors of Leucine Aminopeptidase The synthesis of L-Thr(But)-(L-Phe)n-SL peptides C-terminal labeled with the nitroxide spin label 2,2,5,5-tetramethyl-3-amino-pyrrolidin-1-oxyl, is described and e.s.r. parameters of the labeled compounds are presented. As shown by e.s.r. spectroscopy studies Thr(But)-Phe-SL is a competitive inhibitor of the leucine aminopeptidase and is bound by the enzyme with high affinity.  相似文献   

16.
A new synthetic strategy for the synthesis of novel 6-methyl-3′-aryl spiro[isoxazolo[2,3-b][1,2,4]thiadiazole-2,2′-thiazolidin]-4′-ones (9a–9e) and 6-methyl-3′-aryl spiro[isoxazolo[2,3-b][1,2,4]oxadiazole- 2,2′-thiazolidin]-4′-ones (12a–12e) analogs is described. These compounds showed significant antimicrobial activity against all the standard strains.  相似文献   

17.
The novel reactive antioxidants based on tetrazoles that are stable at room temperature and convertible into the highly reactive nitrileimines by pyrolysis were prepared and the reactivity for carbon–carbon double bonds was evaluated. Antioxidants, i.e., 2-substituted phenyl-5-(3′,5′-di-tert-butyl-4′-hydroxyphenyl)tetrazoles (PHPT) were prepared with the reaction of p-toluenesulfonylhydrazone of 3,5-di-tert-butyl-4-hydroxybenzaldehyde and substituted phenyl diazonium chloride in a mixed solvent of pyridine, ethanol, and water at ?10°C to ?20°C in 31-61% yields. To evaluate the reactivities of PHPT for carbon–carbon double bonds, m-chloro-substituted PHPT was pyrolyzed in an excess of styrene at 160–170°C for 0.5 h to give the 1-(3′-chlorophenyl)-3-(3″,5″-di-tert-butyl-4″-hydroxyphenyl)-5-phenyl-2-pyridazoline in a 44.1% yield by 1,3-dipolar addition reaction of the nitrileimine formed from the m-chloro-substituted PHPT. The thermogravimetric analysis of a mixture of proton isomer of PHPT and liquid polybutadiene showed that PHPT attached to liquid polybutadiene with an accompanying evolution of nitrogen.  相似文献   

18.
1,1′-Bis(4,2′:6′,4″-terpyridin-4′-yl)ferrocene (1) reacts with ZnCl2 to yield a double-stranded 1D-coordination polymer [{Zn2(1)Cl4}∙3CHCl3]n. The 1,1′-functionalized ferrocene core adopts a cisoid-conformation, giving rise to a folded conformation for 1 and a double-stranded 1D-polymer chain. This contrasts with previously reported multi-stranded chains supported by 4,2′:6′,4″-terpyridine ligands in which the multiple-nature of the chain arises from multinuclear metal nodes.  相似文献   

19.
末端为二氟乙烯氧基类液晶分子的合成   总被引:1,自引:0,他引:1  
报道了末端基团为二氟乙烯氧基、具有苯基双环己烷骨架的液晶化合物的合成方法。3,5-二氟溴苯的格氏试剂与烷基双环己基酮偶联,经过脱水、氢化、异构化、类Brown硼氢化、醚化,最后经过消除反应得到5-[反-4′-(反-4″-正丙基环己基)环己基]-1,3-二氟-2-(2′,2′-二氟乙烯氧基)苯,该法原料易得、实验步骤少,总收率15%,其结构经1HNMR确证。  相似文献   

20.
Investigations on the Reaction of Pyrazolone Azomethine Dyes with 2-Pyrazolin-5-one-Derivatives The reaction between pyrazolone azomethine dyes 1 and different 2-pyrazolin-5-ones 2 was investigated. Among the reaction products compounds 5 {3,3′3″-trimethyl-1,1′1″-triphenyl-[4,4′4″-tri-(2-pyrazolin-5-on)]} was isolated, which hitherto was unknown as a product of this reaction. A new reaction pathway is proposed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号