Synthesis,optical, and spectroscopic characterisation of substituted 3-phenyl-2-arylacrylonitriles

The Knoevenagel condensation between aldehydes and substrates with active methylene groups was applied to synthesise a series of 3-(4-substituted phenyl)-2-arylacrylonitriles (aryl = phenyl or pyridyl). Chloro-, fluoro-, or dimethylamino-substituted aryls and a cyano group attached to the double bond of acrylonitrile were studied. Previous studies showed that the condensation products were E isomers. The compounds synthesised were: 3-(4-chlorophenyl)-2-phenylacrylonitrile, 3-(4-chlorophenyl)-2-(pyridin-2-yl)acrylonitrile, 3-(4-chlorophenyl)-2-(pyridin-3-yl)acrylonitrile, 3-(4-chlorophenyl)-2-(pyridin-4-yl)acrylonitrile, 3-(4-fluorophenyl)-2-phenylacrylonitrile, 3-(4-fluorophenyl)-2-(pyridin-2-yl)acrylonitrile, 3-(4-fluorophenyl)-2-(pyridin-3-yl)acrylonitrile, 3-(4-fluorophenyl)-2-(pyridin-4-yl)acrylonitrile, 3-(4-dimethylaminophenyl)-2-phenylacrylonitrile, 3-(4-dimethylaminophenyl)-2-(pyridin-2-yl)acrylonitrile, 3-(4-dimethylaminophenyl)-2-(pyridin-3-yl)acrylonitrile, and 3-(4-dimethylaminophenyl)-2-(pyridin-4-yl)acrylonitrile. Structures were confirmed by IR, MS, and NMR spectral data. Molar absorption coefficient, absorbance, and fluorescence emission spectra were compared in order to evaluate the effects of substituents on phenyl and the position of nitrogen in pyridine moiety on the electronic properties of acrylonitrile derivatives prepared.     

光学活性N-N-二烷基-β-氨基醇硼烷配合物对酮肟醚的不对称还原反应(Ⅱ)

光学活性(S)-(-)-2-(1-吡咯烷基)-1,1-二苯基-丙醇-1(1a)和(S)-(-)-2(1-吡咯烷基)-1,1,3-三苯基-丙醇-1(1b), 分别与过量的硼烷反应, 生成相应的硼烷-手性翁唑硼烷配合物, 可用于脂肪酮肟醚和芳香酮肟醚的碳-氮双键的不对称还原反应, 得到光学活性伯胺, 化学收率则为52~76%, 光学收率为6~99%, 讨论了不同还原底物的结构对立体选择性的影响作用。     

带有四个不同芳基的环丁烷的合成、结构及光化学性质

通过不同杂芳基乙烯分子间的交叉光二聚反应在硫酸溶液中和中压汞灯照射下,合成了4种含7个不同取代芳基的环丁烷衍生物.用紫外和红外光谱及¹H和¹³CNMR谱确定其结构为顺式头尾相对型二聚体.     

Linked porphyrin systems

Porphyrin monomers, 5-(monopyridyl)-10,15,20-(triphenyl)porphyrin ( 1 ), 5,10-(dipyridyl)-15,20-(diphenyl)-porphyrin ( 2 ), and 5,15-(dipyridyl)-10,20-{diphenyl)porphyrin ( 3 ), were linked by hydrocarbon chains to form a series of dimers, trimers and polymers. The 5-(monopyridyl)-10,15,20-(triphenyl)porphyrin monomers were linked by 2, 4, 6, 8 and 10 carbon chains through the alkylation of the pyridine nitrogens using the appropriate diiodoalkane to form positively charged linked dimers 4–8 . A trimer 12 was synthesized from two 5-(monopyridyl)-10,15,20-(triphenyl)porphyrin and one 5,10-(dipyridyl)-15,20-(diphenyl)porphyrin linked by a six carbon chain. Hydrocarbon linked (5,10-(dipyridyl)-15,20-(diphenyl)porphyrin)_n ( 13 ) and (5,15-(dipyridyl)-10,20-(diphenyl)porphyrin)_n ( 14 ) were also prepared.     

New determination methods of halides and cyanide ions by electrospray ionization mass spectrometry based on ternary complex formation

Determination methods of halide ions (X(-) = F(-), Cl(-), Br(-) and I(-)) by electrospray ionization mass spectrometry (ESIMS) were developed, where negative ions of the ternary complexes of group-13 elements, nitrilotriacetic acid (NTA), and halides were measured. In particular, these halides were simultaneously determined by measuring [InX(nta)](-), and the limits of detection (LODs) were 1.1 μmol dm(-3) for F(-), 0.32 μmol dm(-3) for Cl(-), 3.8 nmol dm(-3) for Br(-), and 1.6 nmol dm(-3) for I(-), respectively. This approach was extended to the determination of CN(-), where the ternary complex of Cu(II), CN(-) and 4-(2-pyridylazo)resorcinol (PAR), i.e., [(63)Cu(II)(CN)(par)](-) (m/z 302) was measured. The LOD for CN(-) was 20 nmol dm(-3).     

Conformations of dimethylhydrogen phosphonate (DMHP): a matrix isolation infrared and ab initio study

The infrared spectra of dimethylhydrogen phosphonate (DMHP) isolated in nitrogen, argon and krypton matrices using an effusive source at 298 and 373 K have been recorded. Experiments were also performed using a supersonic jet source to look for conformational cooling in the expansion process. As a result of these experiments, infrared spectral characteristics of the ground and higher energy conformers of the DMHP have been identified for the first time. The structures of DMHP were optimized at the hybrid B3LYP and Hartree fock (HF) levels of theory using the 6-31++G** basis sets. Computationally, four minima were obtained corresponding to DMHP conformers with G (+/-)G (-/+), G (-)G (-), TG (+) and TG (-) structures in the order of increasing energy. Frequency calculations were done to confirm that the structures were indeed minima on the potential energy surface (PES). The computed frequencies corroborated well with the experimental matrix isolation infrared frequencies leading to definite assignments of the infrared features of DMHP, for the G (+/-)G (-/+) and TG (+) conformers. At B3LYP/6-31++G** level, the energy difference between the G (+/-)G (-/+) and G (-)G (-) conformer was 1.53 kcal/mol, and that between G (+/-)G (-/+) and TG (+), G (+/-)G (-/+) and TG (-) were 1.65 and 1.95 kcal/mol. Transition-state calculations were also carried out at B3LYP/6-31++G** level connecting the G (+/-)G (-/+) to G (-)G (-), TG (+) and TG (-) conformers. Computations indicated that the conformer interconversion between G (-)G (-) --> G (+/-)G (-/+) is barrierless, whereas the barriers for TG (+) --> G (+/-)G (-/+) and TG (-) --> G (+/-)G (-/+) are 1.47 and 0.88 kcal/mol, respectively.     

MS2/TOF and LC-MS/TOF studies on toremifene to characterize its forced degradation products

The present study was designed to characterize the possible degradation products of toremifene under varied conditions as prescribed by ICH guidelines Q1A(R2). The forced degradation studies were conducted on toremifene citrate under the conditions of hydrolysis (acidic, basic and neutral), photolysis, oxidation and dry heat. The drug was found unstable to photolysis and hydrolysis in water and acidic media but stable to alkaline hydrolysis, peroxide oxidation and thermal degradation. In total fifteen degradation products (I-XV) were formed, which were resolved from each other and the drug on a C-18 column employing an isocratic elution method. A complete mass fragmentation pattern of the drug was established with the help of LC/ESI-MS/TOF to assist characterization of the degradation products. Of the fifteen products, six products III, IV, VII, VIII, XIV and XV were detected in LC-MS. The molecular masses of III, IV, VII and VIII were found to be the same i.e., 387, while those of XIV and XV were 389 and 403, respectively. Structures of these products were elucidated through comparison of their mass fragmentation patterns with the drug, which were proposed on the basis of accurate masses of the parent and fragment ions. These were characterized as (Z)-2-(2-(dimethylamino)ethyl)-4-(4-hydroxy-1,2-diphenylbut-1-enyl)phenol (III), (E)-2-(2-(dimethylamino)ethyl)-4-(4-hydroxy-1,2-diphenylbut-1-enyl)phenol (IV), (E)-4-(4-(2-(dimethylamino)ethoxy)phenyl)-3,4-diphenylbut-3-en-1-ol (VII), (Z)-4-(4-(2-(dimethylamino)ethoxy)phenyl)-3,4-diphenylbut-3-en-1-ol (VIII), 2-(4-(10-(2-chloroethyl)phenanthren-9-yl)phenoxy)-N-methylethanamine (XIV), and 2-(4-(10-(2-chloroethyl)phenanthren-9-yl)phenoxy)-N,N-dimethylethanamine (XV). Finally, a most plausible mechanistic explanation for degradation of the drug in different chemical environments is also proposed. The results of the study disclose six new degradation related impurities of the drug.     

Determination of L- and D-fucose using amperometric electrodes based on diamond paste

Monocrystalline diamond (natural diamond, synthetic-1 and synthetic-2) based electrochemical electrodes were designed for the analysis of L- and D-fucose. Response characteristics of the electrochemical electrodes were determined using cyclic voltammetry and differential pulse voltammetry (DPV). L-fucose was determined using DPV with electrodes based on natural diamond, synthetic-1 and synthetic-2, respectively, at 240 mV using NaCl as the electrolyte (pH 3.0); at 160 mV using KNO(3) (pH 10.0) and at 80 mV using KCl as the electrolyte (pH 10.0) while D-fucose was analyzed at 120 mV using KCl as the electrolyte (pH 1.0); at 140 mV using KNO(3) as the electrolyte (pH 1.0) and at 160 mV using NaNO(3) as the electrolyte (pH 3.0). The linear concentration ranges for L-fucose were between 10(-13) and 10(-9) mol L(-1) (natural diamond), 10(-11) and 10(-8) mol L(-1) (synthetic-1) and 10(-6) and 10(-3) mol L(-1) (synthetic-2) with detection limits of 10(-14), 10(-12) and 10(-8) mol L(-1) magnitude order, respectively. For D-fucose, the linear concentration ranges were 10(-6) to 10(-3) mol L(-1) (natural diamond), 10(-5) to 10(-3) mol L(-1) (synthetic-1) and 10(-9) to 10(-3) mol L(-1) (synthetic-2) with detection limits of 10(-7), 10(-7) and 10(-10) mol L(-1) magnitude order, respectively. The sensors were used for the assay of L-fucose in serum and urine samples.     

High-performance liquid chromatographic determination of (S)-(-)-ofloxacin and its metabolites in serum and urine using a solid-phase clean-up

A sensitive and selective method for the simultaneous determination of (S)-(-)-ofloxacin [(S)-(-)-OFLX] and its metabolites in serum and urine was developed using isocratic high-performance liquid chromatography with a specific solid-phase extraction procedure. (S)-(-)-OFLX and its metabolites, desmethyl-(S)-(-)-OFLX and (S)-(-)-OFLX N-oxide, were eluted from a C8 solid-phase column with recoveries of more than 98%. These compounds were separated and determined by means of a reversed-phase column with fluorimetric detection. Validation studies showed that the results were linear for (S)-(-)-OFLX in serum over the range 10-1200 ng/ml and in urine over the range 1-200 micrograms/ml. Analysis for (S)-(-)-OFLX and its metabolites showed good precision and accuracy with a relative standard deviation of less than 6%.     

Application of N-(ω-bromoalkyl)tetrazoles for the preparation of bitopic ligands containing pyridylazole chelators or azole rings as building blocks for iron(II) spin crossover polymeric materials

1-(3-Bromopropyl)tetrazole, 2-(3-bromopropyl)tetrazole, 1-(4-bromobutyl)tetrazole, and 2-(4-bromobutyl)tetrazole were synthesized with the aim to prepare flexible bitopic ligands contaning 1- or 2-substituted tetrazole ring linked through 1,3-propylene or 1,4-butylene spacer with pyridylazole or azole unit. Twenty-six novel ligands i.e., α-(pyridylazolyl)-ω-(tetrazolyl)alkanes, α-(tetrazolyl)-ω-(1,2,3-triazolyl)alkanes, and α-(tetrazol-1-yl)-ω-(tetrazol-2-yl)alkanes were prepared by an alkylation of sodium salts of 5-(2-pyridyl)tetrazole, 3-(2-pyridyl)-1,2,4-triazole, 3-(2-pyridyl)pyrazole, 1,2,3-triazole, and 1,2,3,4-tetrazole with N-(ω-bromoalkyl)tetrazoles. An alkylation of 5-(2-pyridyl)tetrazole, 1,2,3,4-tetrazole, and 1,2,3-triazole afforded both N1- and N2-regioisomer whereas in the case of 3-(2-pyridyl)-1,2,4-triazole and 3-(2-pyridyl)pyrazole only N1 isomers were isolated. The positions of alkylation were confirmed by X-ray diffraction studies of 1-(5-(2-pyridyl)tetrazol-2-yl)-4-(tetrazol-1-yl)butane, 1-(3-(2-pyridyl)-1,2,4-triazol-1-yl)-4-(tetrazol-2-yl)butane, 1-(3-(2-pyridyl)pyrazol-1-yl)-4-(tetrazol-1-yl)butane, and 1-(tetrazol-1-yl)-4-(1,2,3-triazol-1-yl)butane. Preliminary investigations of magnetic properties of iron(II) complex with 1-(3-(2-pyridyl)-1,2,4-triazol-1-yl)-4-(tetrazol-1-yl)butane revealed that obtained product exhibit thermally induced spin transition accompanied by the thermochromic effect.     

3, 3-不对称二取代甲基氧杂丁环的合成

以2,2-二(溴甲基)-1,3-丙二醇(1)为原料合成了3-溴甲基-3-羟甲基氧杂丁环(2)、3-乙氧甲基-3-羟甲基氧杂丁环(3)、3-叠氮甲基-3-羟甲基氧杂丁环(4)、3-叠氮甲基-3-硝酸酯甲基氧杂丁环(5)、3-溴甲基-3-硝酸酯甲基氧杂丁环(6)及3-乙氧基甲基-3-硝酸酯甲基氧杂丁环(7)共六种3,3-不对称二取代甲基氧杂丁环化合物,其中6和7的合成未见文献报道。也提出了合成5的改进路线。     

New nucleoside analogs from 2-amino-9-(beta-D-ribofuranosyl)purine

Four novel derivatives of 2-amino-9-(beta-D-ribofuranosyl)purine (1) were synthesised and fully characterised. When 1 was reacted with chloroacetaldehyde (a), 2-chloropropanal (b), bromomalonaldehyde (c) and a mixture of chloroacetaldehyde + malonaldehyde (d), 3-(beta-D-ribofuranosyl)-imidazo-[1,2a]purine (2), 3-(beta-D-ribofuranosyl)-5-methylimidazo-[1,2a]purine (3), 3-(beta-D-ribofuranosyl)-5-formylimidazo-[1,2a]purine (4) and 9-(beta-D-ribofuranosyl)-2-(3,5-diformyl-4-methyl-1,4-dihydro-1-pyridyl)purine (5) were formed, respectively. The products were isolated, purified by chromatography and characterised by MS, complete NMR assignment as well as fluorescence and UV spectroscopy. The yields of these reactions were moderate (14-20%). The fluorescence properties differed from those of the starting compound and the quantum yields were considerably lower.     

Synthesis of New 1,3-Thiazolecarbaldehydes

H-Lithiation and Br-lithiation reactions of 1,3-thiazole were studied in order to obtain new thiazole derivatives. Four isomeric chloromethyl derivatives of 1,3-thiazole containing a protected aldehyde group like 2-(1,3-dioxolan-2-yl)-5-(chloromethyl)-1,3-thiazole, 5-(1,3-dioxolan-2-yl)-2-(chloromethyl)-1,3-thiazole, 4-(1,3-dioxolan-2-yl)-2-(chloromethyl)-1,3-thiazole, and 2-(1,3-dioxolan-2-yl)-4-(chloromethyl)-1,3-thiazole were synthesized. Their nucleophilic substitution reactions with dimethylamine and sodium methylthiolate were studied. New aldehydes of 1,3-thiazole series of low-molecular weight were obtained.     

New sesquiterpenes and calebin derivatives from Curcuma longa

One novel sesquiterpene with new skeleton, (6S)-2-methyl-6-(4-hydroxyphenyl-3-methyl)-2-hepten-4-one (1), two new bisabolane sesquiterpenes, (6S)-2-methyl-6-(4-hydroxyphenyl)-2-hepten-4-one (2), (6S)-2-methyl-6-(4-formylphenyl)-2-hepten-4-one (3), and two calebin derivatives, 4'-(4'-hydroxyphenyl-3'-methoxy)-2'-oxo-3'-butenyl-3-(4'-hydroxyphenyl)-propenoate (4) and 4'-(4'-hydroxyphenyl)-2'-oxo-3'-butenyl-3-(4'-hydroxyphenyl-3'-methoxy)-propenoate (5) were isolated along with five known bisabolane sesquiterpenes from Curcuma longa. 1-4 were new compounds and 5 was a new natural product. Their structures were established by spectral methods.     

3,3-二{2,2-二[4-(N,N-二取代氨基)苯基]乙烯基}-4,5,6,7-四氯-2-苯并[c]呋喃酮的合成

在对甲苯磷酸存在下,采用1,1-二[4-(N,N-二取代氨基)苯基]乙烯(3)和四氯苯酐在乙酸酐溶液中的缩合反应合成了3,3-二{2,2-二[4-(N,N-二取代氨基)苯基]乙烯基}-4,5,6,7-四氯-2-苯并[c]呋喃酮(4),产率89～93％。3由4,4＇-二(N,N-二取代氨基)二苯甲酮(1)与甲基碘化镁进行Grignard反应的产物经水解再脱水制得,产率85％～88.5％(以1为基准)。     

Anti-babesial compounds from Curcuma xanthorrhiza

Anti-babesial ingredients, (12R)- and (12S)-12,13-dihydro-12,13-dihydroxyxanthorrhizols, were isolated from Curcuma xanthorrhiza. The structures were established by the extensive NMR techniques. The assignments of (1)H NMR data of (12R)-12,13-dihydro-12,13-dihydroxyxanthorrhizol was revised, and (12S)-12,13-dihydro-12,13-dihydroxyxanthorrhizol was isolated as a pure form for the first time. The IC(50) of the active compounds were compared with that of commercial drug, diminazene aceturate (Ganaseg). IC(50) values of Ganaseg, (12R)-, and (12S)-12,13-dihydro-12,13-dihydroxyxanthorrhizols were 0.6 microg mL(-1), 8.3 microg mL(-1) and 11.6 microg mL(-1), respectively.     

[Z]-2-(芳基锡基)-1-(9-芴醇)乙烯的合成、结构与性质

用三苯基氢化锡,三对甲苯基氢化锡作为锡氢化试剂与9-乙炔基-9-芴醇进行反应,合成了2个有机锡化合物:[Z]-2-(三苯基锡基)-1-(9-芴醇)乙烯(1)和[Z]-2-(三对甲苯基锡基)-1-(9-芴醇)乙烯(2)。化合物1和2分别与ICl,Br~2,I~2反应,得到6个有机锡一卤化物,6个有机锡二卤化物和2个有机锡混合卤化物(3-16)。有机锡一碘化物7,13和有机锡二碘化物8,14与KOH乙醇溶液反应,分别得到相应的有机锡氢氧化物17,18和有机锡氧化物19,20。有机锡二碘化物8,14分别与含氮双齿配体1,10-邻菲罗啉(Phen),2,2'-联吡啶(Bipy),8-羟基喹啉(Oxin)反应,得到6个相应的配合物21-26。26个新化合物通过元素分析,锡含量测定,IR,^1HNMR测定对其结构进行了表征。同时测定了化合物2的晶体结构,晶体属单斜晶系,空间群P2~1/c。化合物2是以Sn原子为中心扭曲的四面体构型。     

1,3,4-噁二唑键联二芳基乙烯化合物的合成及性质

将1,3,4-噁二唑基团引入二芳基乙烯分子中, 合成了2种新的二芳基乙烯类光致变色化合物1-氰基-2-(2H-5-苯基-1,3,4-噁二唑)-1,2-二(2,4,5-三甲基-3-噻吩)乙烯(3)和1,4-二{[1-氰基-2-(2H-5-苯基-1,3,4-噁二唑)-1,2-二(2,4,5-三甲基-3-噻吩)乙烯]-1,3,4-噁二唑}苯(4). 通过IR, NMR, MS和元素分析对化合物进行了结构表征, 并研究了其UV-Vis吸收、荧光发射、动力学特性和抗疲劳性质. 实验结果表明, 化合物[STHZ]3[STBZ]和[STHZ]4[STBZ]具有良好的光致变色性质, 光致变色闭环反应为零级反应, 开环反应为一级反应.     

铜(Ⅰ)配合物的不对称催化1,4-共轭加成反应

以两个新型手性配体S-(+)-2-(2-吡啶酰胺基)-2'-(二苯基膦基)-1,1'-联苯(1a)和S-(+)-2-(6-甲基-2-吡啶酰胺基)-2'-(二苯基膦基)-1,1'-联萘(1b)的铜配合物催化的二乙基锌对开链烯酮的1,4-共轭加成反应的研究。以1a为标准配体,查耳酮为代表性底物,考察了溶剂、催化剂前体等因素对反应的影响。在优化条件下,系统研究了以[Cu(OTf)](C~6H~6)~1~/~2/1b为催化剂,甲苯-二氯乙烷为溶剂时进行了二乙基锌对七个开链烯酮的1,4-共轭加成反应,取得了突破性进展,获得最高达98%e.e.值的加成产物。     

Synthesis and electropolymerization studies of non-aggregated (4-{3-[3-(dimethylamino,diethylamino)phenoxy]propoxy}phenyl)propanoxy substituted silicon naphthalocyanines

In this study, 3-(4-{3-[3-(dimethylamino)phenoxy]propoxy}phenyl)propan-1-ol, 3-(4-{3-[3-(diethylamino)phenoxy]propoxy}phenyl)propan-1-ol and axially disubstituted silicon naphthalocyanines (SiNc) bearing electropolymerizable bis-[(4-{3-[3-(dimethylamino)phenoxy]propoxy}phenyl)propanoxy] and bis-[(4-{3-[3-(diethylamino)phenoxy]propoxy}phenyl)propanoxy] units were synthesized for the first time. Aggregation behavior of SiNcs was examined in different solvents and concentrations in DMSO. In all solvents and concentrations, SiNcs were non-aggregated. Also, electrochemical studies of SiNcs were investigated by cyclic and square wave voltammetry. While SiNcs gave only naphthalocyanine-based reduction process during the cathodic potential scans, they were electropolymerized on the working electrode during the anodic potential scan because of the oxidative electropolymerization of (4-{3-[3-(dimethylamino)phenoxy]propoxy}phenyl)propanoxy and (4-{3-[3-(diethylamino)phenoxy]propoxy}phenyl)propanoxy groups on the substituents of the complexes.