共查询到20条相似文献,搜索用时 281 毫秒
1.
以2,5-二巯基-1,3,4-噻二唑为原料, 与水合肼缩合, 生成2,5-二肼基-1,3,4-噻二唑. 2,5-二肼基-1,3,4-噻二唑与苯甲酰氯反应生成2,5-二酰肼基-1,3,4-噻二唑, 以POCl3为环合剂环合酰肼基-1,3,4-噻二唑, 合成3,6-二取代苯基- 二-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑衍生物, 合成的新化合物的结构通过元素分析、红外光谱、核磁共振氢谱和质谱予以证实, 并提出了环化反应机理. 相似文献
2.
3.
4.
《化学研究与应用》2015,(7)
合成了四种噻二唑衍生物:2,5-二苯基-1,3,4-噻二唑(DPTD),2,5-二(2-羟基苯)-1,3,4-噻二唑(2-DHPTD),2,5-二(3-羟基苯)-1,3,4-噻二唑(3-DHPTD)和2,5-二(4-羟基苯)-1,3,4-噻二唑(4-DHPTD)。采用Tafel极化测试、电化学阻抗谱(EIS)和扫描电子显微镜(SEM)研究了噻二唑衍生物在50 mg·L-1硫-乙醇体系中对银的缓蚀作用。实验结果表明:添加缓蚀剂后,银片腐蚀得到抑制,且缓蚀效率大小顺序为:[DPDT][2-DHPDT][3-DHPDT][4-DHPDT]。通过量子化学计算和分子动力学模拟进一步研究了四种噻二唑衍生物的缓蚀机理,理论计算结果与实验结果一致。 相似文献
5.
采用氰基丙烯酸酯与5-乙氧基-1,3,4-噻二唑-2-甲氨在乙醇中加热回流的方法合成了一系列3-(5′-乙氧基-1,3,4-噻二唑-2′-亚甲氨基)-2-氰基-3-取代-丙烯酸酯类化合物.目标化合物结构均经1HNMR和元素分析确证.生物活性测试结果表明,部分化合物对双子叶杂草油菜和苋菜显示出较好的除草活性及良好的选择性,用化合物6j在600g/ha剂量下对油菜和苋菜茎叶进行处理,抑制率仍达100%和95.2%,与对照样B相当;氰基丙烯酸酯3位取代基体积对除草活性影响较大,3位为异丙基时活性最高. 相似文献
6.
2,5-二(邻羟苯基)-1,3,4-噻二唑与铜的显色反应及应用 总被引:6,自引:0,他引:6
研究了在两性表面活性剂十二烷基二甲基氧化铵(OB-2)存在下,铜与新合成试剂2,5-二(邻羟苯基)-1,3,4-噻二唑的显色条件,建立了测定铜的新方法。在pH8.0NH3-NH4Cl缓冲溶液中,铜与2,5-二(邻羟苯基)-1,3,4-噻二唑反应生成1∶3黄绿色配合物,最大吸收波长为410nm。加入OB-2后,最大吸收波长红移至470nm,表观摩尔吸光系数为4.23×104L.mol-1.cm-1,铜量在0.4~2.4μg/mL范围内服从比耳定律,可用于水样中铜的测定,回收率在97.1%~98.7%之间。 相似文献
7.
2-氨基-5-取代-1,3,4-噻二唑与2-氯代-1-(2,4-二氯苯基)乙酮的反应研究 总被引:1,自引:0,他引:1
2-氨基-5-烷基/芳基1,3,4-噻二唑与2-氯代-1-(2′,4′-二氯苯基)乙酮在热乙醇中反应生成一系列2-烷基/芳基-6-(4,4-二氯)苯基咪唑并[2-1-b]-1,3,4-噻二唑.产物通过元素分析, IR, 1H NMR, 13C NMR及MS分析,化合物5g的X衍射晶体结构分析表明,产物的芳基是在咪唑并[2-2-b]-1,3,4-噻二唑的6-位而不在5-位. 相似文献
8.
2,5-二(邻羟苯基)-1,3,4-噻二唑与钴显色反应的研究 总被引:7,自引:0,他引:7
研究了在两性表面活性剂十二烷基二甲基氧化胺(OB-2)存在下,钴与新合成试剂2,5-二(邻羟苯基)-1,3,4-噻二唑的显色条件及应用,建立了测定钴的新方法。在pH 8.0 NH3-NH4Cl缓冲溶液中,钴与2,5-二(邻羟苯基)-1,3,4-噻二唑反应生成1∶3黄绿色螯合物,最大吸收波长为410 nm。加入OB-2后,使其最大吸收波长红移至470 nm,表观摩尔吸光系数为5.74×104L.mol-1.cm-1,钴质量浓度在0.2~2.4μg/mL范围内服从比耳定律,可用于维生素B12针剂和水样中钴的测定,回收率在97.7%~98.2%之间。 相似文献
9.
10.
以非金属硒作为催化剂,以CO替代剧毒光气作为羰基化试剂,以O2作为氧化剂,通过2-氨基-1,3,4-噻二唑与醇以"一锅法"方式发生硒催化氧化羰基化反应,提出了一种成本低、原子经济性高、合成路线简短及环境相对友好的合成1,3,4-噻二唑-2-氨基甲酸酯类化合物的新方法.研究了反应温度、醇的用量、压力及碱的种类等对合成1,3,4-噻二唑-2-氨基甲酸酯的影响,在优化反应条件下,2-氨基-1,3,4-噻二唑可与一系列醇顺利发生羰基化反应,以45%~90%的收率得到1,3,4-噻二唑-2-氨基甲酸酯类化合物. 相似文献
11.
B. Sepehri 《SAR and QSAR in environmental research》2017,28(12):957-971
Ligand-based virtual screening (LBVS) and structure-based virtual screening (SBVS) approaches were used to identify new inhibitors for ATAD2 bromodomain. The LBVS approach was used to search 23,129,083 clean compounds to identify compounds similar to an active compound with reported pIC50 equal to 7.2. Based on LBVS results, 19 compounds were selected. To perform SBVS, by applying nine filters on 23,129,083 clean compounds, 1,057,060 compounds were selected. After performing SBVS on these selected compounds with idock software, 16 compounds with the lowest binding energies were selected. More accurate molecular docking analysis was performed on these 35 selected compounds by using iGEMDOCK software and six of them with the lowest binding energies were selected as hit compounds. These compounds were zinc36647229, zinc77969074, zinc13637358, zinc77971540, zinc12991296 and zinc19374204. 相似文献
12.
为全面了解小米黄酒风味成分的构成和气味特征,优化了85μm聚丙烯酸酯(PA)、100μm聚二甲基硅氧烷(PDMS)、75μm碳分子筛(CAR)/PDMS、50/30μm二乙烯基苯(DVB)/CAR/PDMS萃取头提取小米黄酒风味成分的条件,采用顶空固相微萃取(headspace solid phase microextraction,HS-SPME)-气相色谱-质谱法(GC-MS)对风味成分进行定性、定量分析,并计算气味活性值(odor active value,OAV),同时利用OAV分析风味成分的气味特征和气味强度。结果显示:不同萃取头的最优萃取条件为样品量8 mL、萃取时间40 min、萃取温度60℃、NaCl添加量1.5 g。小米黄酒风味成分由醇、酯、含苯化合物、烃、酸、醛、酮、烯、酚和杂环类化合物构成,醇为主要风味成分。通过OAV确定了苯乙醇、苯乙烯、2-甲基萘、1-甲基萘、苯甲醛、苯乙醛、2-甲氧基-苯酚为小米黄酒气味特征成分,苯基乙醇、苯乙醛对气味贡献最大。PA和PDMS萃取头分别对极性和非极性化合物具有较好的吸附效果,CAR/PDMS和DVB/CAR/PDMS萃取头对中等极性化合物具有较好的吸附效果。该研究全面了解了小米黄酒风味成分的构成,为其产品开发及品质控制提供理论了依据。 相似文献
13.
14.
Gerhard Full Peter Winterhalter Gertraut Schmidt Peter Herion Peter Schreier 《Journal of separation science》1993,16(11):642-644
This paper reports the differentiation between the enantiomers of theaspiranes and theaspirones, potent flavor compounds widely used in the flavor industry. Optically pure reference compounds of isomeric theaspiranes were obtained by enantioselective synthesis. Enantiomerically pure reference theaspirones were isolated from quince fruit; their absolute stereochemistry was assigned by CD spectroscopy. For both types of compounds the order of elution was elucidated by using authentic reference compounds. These data enabled the determination of the enantiomeric distribution of both types of compounds in a variety of plant tissues. Because of the complexity of the natural flavor isolates, compounds were identified by mass spectrometry after multidimensional gas chromatography employing a Sichromat 2 double oven chromatograph. After separation of the target compounds on the first, achiral, column (DB-5), they were transferred to a chiral column (C-Dex B) for determination of the enantiomeric distribution. Multiple ion detection (MID) enabled the determination of the enantiomeric distribution even for complex mixtures containing the target compounds at extremely low levels. 相似文献
15.
Rui Zhao Chunyan TanYonghua Xie Chunmei GaoHongxia Liu Yuyang Jiang 《Tetrahedron letters》2011,52(29):3805-3809
A general and efficient method for synthesis of both symmetric and asymmetric aromatic azo compounds in one single step has been developed. The nitro compounds were reduced and the substituted anilines were oxidized by each other without any metal in the base condition. Various azo compounds with halogen, methyl and methoxy functional group were obtained by using available, cheap nitro compounds and substituted anilines. In addition, the electronic effect and substituent effect of the compounds have been discussed. 相似文献
16.
Gas chromatography-olfactometry analysis of the volatile compounds of two commercial Irish beef meats 总被引:1,自引:0,他引:1
The volatile flavour compounds of two commercial Irish beef meats (labelled as conventional and organic) were evaluated by gas chromatography-olfactometry and were identified by gas chromatography-mass spectrometry. The volatile compounds were isolated in a model mouth system. Gas chromatography-olfactometry was performed by a group of eight assessors using the detection frequency methodology. The odours of the detected compounds were described as well. Eighty-one volatile compounds were identified, 11 compounds of which possessed odour activity in the first beef sample and 14 of which in the second meat sample. Ten volatile flavour compounds were common to both: methanethiol, dimethyl sulphide, 2-butanone, ethyl acetate, 2- and 3-methylbutanal, an unknown compound, 2-octanone, decanal and benzothiazole. Two unknown compounds were only detected in the first sample while 2,3-pentanedione, 4-methyl-3-penten-2-one, 2-heptanone, dimethyl trisulphide and nonanal were only perceived in the second beef. Significant differences in terms of detection frequency, odour characteristics and in nature of the volatile flavour compounds were emphasised between the two samples. 相似文献
17.
18.
Y. Saito Y. Miyamoto M. Magara S. Sakurai S. Usuda 《Journal of Radioanalytical and Nuclear Chemistry》2003,255(2):341-345
In order to examine the feasibility of the adsorbed compounds on the pine needles for environmental monitoring of uranium, the adsorbed compounds were recovered by solvent washing, and the elemental concentrations in the compounds were compared with those of air particles and pine needles. It was found, that the concentration patterns of elements in the compounds corresponded to those of air particles, which meant that the air particles were the main components of the compounds. The analysis by ICP-MS suggested that the uranium in the compounds has a natural composition. Therefore, the adsorbed compounds to the pine needles can be considered as potential indicators for the environmental monitoring of uranium. 相似文献
19.
催化柴油中氮化物分布的气相色谱-原子发射光谱分析方法的研究 总被引:4,自引:1,他引:3
建立了催化柴油馏分中各种氮化物类型分布的气相色谱-原子发射光谱(GC-AED)分析方法,考察了色谱条件和不同的试剂气压力对各种氮化物分离和检测灵敏度的影响,定性(或归类)了某典型催化柴油中的73个氮化物,计算了程升条件下各种氮化物的保留指数,为不同实验室的定性比较提供了依据。以峰面积对质量浓度作图,氮化物在2.0~600 mg/L浓度范围内,AED检测器对不同氮化物有良好的线性响应,线性相关系数达0.998。几种氮化物(吲哚、1-甲基吲哚、C2-吲哚、咔唑、1-甲基咔唑、1,8-二甲基咔唑)峰面积的相对标 相似文献
20.
利用溶剂萃取和柱色谱等技术浓缩分离新疆宝明页岩油柴油馏分中的碱性氮化物。以宝明页岩柴油为原料,经糠醛溶剂精制,初步得到富集碱性氮化物的抽出油。以抽出油为深度富集碱性氮化物的原料,采用柱色谱等分离方法,从抽出油中分离得到碱性氮化物。利用傅立叶变换红外光谱仪(FT-IR)和气相色谱-质谱联用仪(GC-MS)分别对富集的碱性氮化物进行官能团检测和定性、定量分析。结果表明:新疆宝明页岩油柴油馏分中的碱性氮化物经溶剂精制和柱色谱等分离方法梯度富集后,碱性氮化物的质量分数由抽出油的12.08%提高到最终产物的69.48%,并在富集分离的产物中鉴定出60种碱性氮化物,其中主要为苯胺类、喹啉类和吡啶类化合物,各占25.85%,23.56%和16.52%。 相似文献