5-α-(磷酸基)苄基-2-甲基-4-羟基咪唑衍生物的电子轰击质谱研究

本文报道了六种新的咪唑衍生物的电子轰击质谱,着重讨论了P--C, P--N键的断裂; 产物离子的开环反应;产物离子的H重排反应和失去CO的反应等. 根据高分辨精确质量测量和联动扫描技术, 讨论了化合物的质谱裂解机理.     

2种吲哚衍生物的N-烷基化产物的制备

吲哚-3-乙醛酸甲酯和3-吲哚乙腈在碱存在下,以烷基卤或硫酸烷基酯为亲电试剂进行N-烷基化反应,合成了6种新的N-烷基化吲哚化合物。 研究了吲哚化合物及烷基化试剂的结构、溶剂和碱对N-烷基化反应的影响。 具有强吸电子取代基的吲哚-3-乙醛酸甲酯使用弱碱Cs2CO3在室温就可顺利进行烷基化反应,产率达到93%;而具有较弱吸电子取代基的3-吲哚乙腈,需要使用强碱NaH才能进行烷基化反应。     

双(取代苯酰氧基)二茂钛衍生物的质谱分析

二茂钛类衍生物具有催化抗肿瘤活性,因而引起人们的研究兴趣。我们曾探讨了一系列双(取代苯酰氧基)二茂钛衍生物、含茂钛聚合物的合成、光谱、质谱及其反应性。本文报道有关衍生物的质谱分析,并讨论其规律性。     

钯催化C-N偶联构筑吲哚衍生物反应研究

以炔基苯胺衍生物为底物,通过钯催化C-N偶联合成一类系列吲哚衍生物。优化实验表明,以2%醋酸钯为催化剂,4%三苯基磷为配体,在有机碱的DMF溶液中加热至130℃为优化实验条件。产物结构经IR、1H NMR、13C NMR、HRMS分析确证,其中化合物2e经X射线单晶衍射分析确证。     

新型取代吲哚-3-甲醇类衍生物的合成

以取代吲哚为原料,经维尔斯迈尔-哈克反应制得取代吲哚-3-甲醛,再通过DMSO/NaOH体系制得N-取代吲哚-3-甲醛(3a~3g);3a~3g经Na BH4还原合成了7个未见文献报道的取代吲哚-3-甲醇类衍生物(4a~4g),其结构经~1H NMR,~(13)C NMR和MS表征。     

取代-苄氧基吲哚-3-甲醛-(4''''-硝基)苯腙的合成

以取代苄氧基吲哚-3-甲醛和4-硝基苯肼为原料,乙醇为溶剂,通过缩合脱水反应合成了4个新化合物--取代苄氧基吲哚-3-甲醛-(4'-硝基)苯腙,其结构经1H NMR,IR,MS和元素分析表征.     

2-苯氧(硫)甲基-6,7-亚甲二氧-3-喹啉酸乙酯及其衍生物的合成

6-氨基胡椒醛与乙酰乙酸乙酯在碱的催化下, 缩合产物与NBS发生溴代反应, 生成2-溴甲基-6,7-亚甲二氧基-3-喹啉酸乙酯,产物与苯酚,取代苯酚, 苯硫酚, 取代苯硫酚发生Williamson取代反应, 高分辨地得到一系列喹啉吩醚衍生物, 苯酚和硫酚上的吸电子基团有利于增强亲核能力,有利于Williamson反应.     

2-(1H-吲哚-3-基)-5-砜基噁二唑衍生物的合成及其生物活性研究

以吲哚-3-甲酸甲酯为原料,通过肼解、环合生成5-(1H-吲哚3-基)-1,3,4-噁二唑-2-硫醇,再对其进行亲核取代和氧化反应得到目标化合物,并通过¹H NMR、¹³C NMR和HRMS确认其结构。采用噻唑蓝(MTT)法测试了目标化合物对几种癌细胞的体外抑制活性,同时采用比浊法对几种植物病原菌进行了体外抑菌活性测试。结果表明,化合物对于A549(人肺癌细胞)、PC-3(人前列腺癌细胞)、K562(人慢性髓原白血病细胞)和HepG2(人肝癌细胞)四种癌细胞有一定的抑制活性;对水稻白叶枯病菌(Xanthomonas oryzae pv.oryzae,Xoo)、柑橘溃疡病菌(Xanthomonas axonopodis pv.citri,Xac)以及猕猴桃溃疡病菌(Pseudomonas syringae pv.actinidiae,Psa)三种植物病菌同样具有一定的抑菌活性。其中,化合物4f对Xoo的体外抑制率可达87.09%(100μg/mL)和54.02%(50μg/mL)。本文结果可为具有砜结构的吲哚衍生物的合成及应用研究提供参考。     

3-取代芳基-2-吲哚基膦酸酯的合成

本文根据Fischer吲哚合成法制备了一系列的3-取代芳基-2-吲哚基膦酸酯. 盐酸苯肼与o,o-二异丙基-4-氯-苯乙酰基膦酸酯在无水酒精中反应, O,O-二异丙基-(4'-氯苯-3H-吲哚-2-膦酸酯能被分离出来, 而且它的异构化最终产物能被观察到.     

Characterizing the electrospray ionization mass spectral fragmentation pattern of indole derivatives synthesized from 2-keto glycosides

Four indole derivatives synthesized from 2-keto glycosides were analyzed by electrospray ionization tandem mass spectrometry (ESI-MSn) with low-energy collision-induced dissociation to establish a general structural elucidation of indole derivatives. Their fragmentation pathways are proposed on the basis of the MSn studies and deuterium-labeled experiments. Indole derivatives undergo complicated gas-phase rearrangements in addition to simple bond cleavages. A rearrangement, which involves a contraction of the six-membered ring, was observed and a mechanism was proposed. The observations may have some potential applications in the interpretation of the mass spectra of indole derivatives.     

SmI2 mediated synthesis of 2,3-disubstituted indole derivatives

A novel preparation of 2,3-disubstituted indole derivatives was achieved through SmI₂ induced intramolecular reductive coupling reactions of acylamido carbonyl compounds.     

Mass Spectral Behavior of Some Indole Schiff-Base Derivatives

TheanalysisofMSdataoftwentytwoindoleSchiff-basederivativesindicatesaclassofspeciticfragmentions(Tablcl).ThesespecificfragmentionsareX.YandZ.IJereweputforwardthepossibleMScleavagemechanismofformingthesespecifictyagmentions.Thestructuresofthetwenty-twoderivativesareconfirmedbyIH-NMRdata'.AsseenfromTablel,Xisakindofspecificfragmentions,i.e.[M--27]'or[(MH=O)--27]'.ThedevelopmentofM --27fragmentionmaygothroughfourmemberedtransitionstate'andM'losesHCfbyinnerextrusion(Figurcl).Theanalysis…     

C2对称的手性双噁唑啉和双噻唑啉的质谱碎裂机理研究

The electron impact mass spectra of ten new C2-symmetric chiral bis(oxazoline) and bis(thiazoline) have been studied. Bis(thiazoline) and bis(oxazoline) possess the same fragmentation mechanism under EI conditions. An unusual fragmentation pathway has been found in the compounds studied. Due to the presence of phenyl group, compounds 6 and 10 undergo a new fragmentation pathway except for the common way as the other eight compounds.Mass analyzed ion kinetic energy spectra experiments and high resolution accurate mass measurement were conducted to confirm the proposed fragmentation pathways.     

Synthesis of bis(indole)-1,2,4-triazinones

A facile method for the synthesis of para- and meta-substituted bis(indole)-1,2,4-triazinones is presented. Our approach to access these triazinones involves a cyclocondensation reaction between amidrazone and ketoester functionalities. The structures of these interesting compounds were established unambiguously by X-ray crystallography.     

p-TsOH promoted Fischer indole synthesis of multi-substituted 2-trifluoromethyl indole derivatives

A p-TsOH promoted one-pot synthesis of multi-substituted 2-trifluoromethyl indole derivatives, for instance, 2-trifluoromethyl-3-phenylindoles, 2-trifluoromethyl-indole-3-propanoates, and 2-trifluoromethyl-indole-3-butanoates from reactions of 1,1,1-trifluoro-3-phenylacetone and simply prepared ω-trifluoromethyl substituted δ and ?-ketoesters with arylhydrazines via Fischer indole synthesis has been developed.     

Mass spectrometric characterization of substituted 2-thiazolin-4-one derivatives

Electron ionization mass spectrometry was used for the structural characterization of substituted 2-thiazolin-4-one derivatives in the gas phase. The compounds follow common fragmentation pathways, producing ions whose abundances are dependent on the chemical nature of the substituent at position 2. Collision-induced dissociation tandem mass spectrometric experiments, carried out on both molecular ions and fragment ions produced in the source, allowed the elucidation of gas-phase decompositions. The presence of tautomeric forms is suggested for some ionic species. Rapid identification of a primary or secondary amine moiety at position 2 of the thiazoline ring can be achieved by the detection of characteristic fragmentations occurring both in the ion source and under the collision-induced dissociation regime.     

Structure elucidation and X-ray crystallographic study of 3-(naphth-1-ylmethyl)indole

Synthesis and structure determination of 3-(naphth-1-ylmethyl)indole are reported. The molecular and crystal structures together with the molecular formula were determined by spectral and single crystal X-ray studies. X-ray crystallography revealed the presence of two conformers arising from the flipping of the naphthalene unit. The crystal of the compound belongs to the triclinic crystal system and space group \(P\bar 1\). Crystal data are as follows: a = 10.302(5) Å, b = 12.522(4) Å, c = 13.383(4) Å, α = 111.9(1)°, β = 116.86(6)°, γ = 71.65(5)°; V = 1726.429 ų; Z = 4. The final R and Rw are R = 0.0744 (on observed F′s); R = 0.0924 (all F data), R _w = 0.1757 (observed F ²) and R _w = 0.1834 (all F ² data).     

Mass spectrometric studies of 2-aryl-5-acetylthiazole derivatives

Electron ionisation mass spectrometry was usefully used to characterize structurally 2-aryl-5-acetylthiazole derivatives in the gas phase. The compounds show characteristic fragmentation pathways depending on the chemical nature of the substituent at position 2, consisting mainly in the cleavage of both the 1,2- and 3,4-bonds of the thiazole ring. Liquid secondary ion mass spectrometry was applied to study the effects of protonation on the gas-phase unimolecular reactions of this class of compound. Tandem mass spectrometric experiments, carried out on molecular and protonated molecular ions, and also on fragment ions produced in the source, allowed the elucidation of gas-phase decompositions of low-internal energy ions.