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1.
以甲苯为起始原料,通过傅克-酰基化、Aldol反应合成了具有稳定烯醇结构的3-氯-2-羟基-4-羰基-4-对甲苯基-2-丁烯酸乙酯,反应过程生成了中间体3,3-二氯-2-羟基-4-羰基-4-对甲苯基丁酸乙酯,采用红外、核磁共振谱、HRMS产品进行了测定和结构表征。对反应机理进行了初步探讨。  相似文献   

2.
本文报道了新显色剂1-(2-咪唑偶氮)-2-萘酚-4-磺酸(IANS)的物理性质、酸离解常数,并对该试剂作为EDTA络合滴定Cu~(2+)、Zn~(2+)、Pb~(2+)、Cd~(2+)、和Hg~(2+)的指示剂进行了研究,结果与二甲酚橙比较令人满意。  相似文献   

3.
合成了内 -α-甲基 -α-取代双环 [2· 2· 2 ]-5 -辛烯 -2 -基甲醇和内 a-甲基 -α-取代双环 [2· 2· 2 ]辛烷 -2 -基甲醇共 2 0个化合物 ,其中 1 8个未见报道。通过 IR、1HNMR、对 MS碎片解析并配合气相色谱测定纯度确证了它们的结构 ,请评香专家评定了它们的香气 ,并讨论了化合物结构和香气之间的关系。  相似文献   

4.
我们已报道了1-对甲苯磺酰基-2-苯氧基-3-芳基-4-苯基-1,4,2-二氮磷酰杂环戊-5-酮的合成及除草活性[1],为了进一步探讨3-位取代基的变化对这类1,4,2-二氮磷酰杂环戊-5-酮的除草活性的影响,按如下方法合成了相应的3-位烷基取代的1-对甲苯磺酰基-4-苯基-1,4-二氮-2-磷酰杂环戊-5-酮(2),并对脂肪醛与1及亚磷酸酯的酸催化反应机理进行了初步探讨.用元素分析、NMR、MS证实了化合物2的结构.初步除草活性测定结果表明,2具有一定的除草活性;其除草活性比相应的3-位芳基取代类化合物的低[1].R:2a,H;2b,Me;2c,Et;2d,n-Pr…  相似文献   

5.
刘胜利  戴静芳  陈勇  曹国标  刘汉文 《有机化学》2004,24(12):1583-1586
合成了3-(2-羟基苯基)-5-苯基-6-乙氧羰基-2-环己烯酮.通过元素分析、红外光谱、紫外光谱、核磁共振氢谱和质谱对其组成和结构进行了表征.利用X射线衍射分析方法测定了它的晶体结构.该化合物的晶体属单斜晶系,空间群P21/c,a=1.41946(17)nm,b=0.58445(7)nm,c=2.1756(3)nm,β=104.795(2)°,V=1.7450(4)nm3,Z=4,Dc=1.280 g·cm-3,F(000)=712,μ=0.088mm-1,R1[I>2σ(I)]=0.0627,wR2[I>2σ(I)]=0.1484.晶体结构测定结果表明化合物分子中的环己烯部分为半椅式构象,分子间通过氢键形成具有16元环的二聚体.  相似文献   

6.
李超  覃章兰  李秀文  张欣 《有机化学》2005,25(5):587-590
合成了12个未见文献报道的4-甲基-苯磺酸2-氧-2-[3-(5-芳基-[1,3,4]噁二唑-2-基)-硫脲]-乙基酯, 其结构经元素分析、1H NMR和IR确证. 初步活性测试结果表明: 部分化合物有较好的杀菌活性.  相似文献   

7.
用电导滴定法研究了乙醇-水溶液中稀土与1’-苯基-3’-甲基-5’-氧代吡唑-4’-基-甲酰甲酸及1,10-二氮杂菲的配合反应。合成了固态配合物。经化学分析与元素分析确定了配合物的化学组成为Ln_2L_3P_2·nH_2O,通过红外光谱、紫外光谱、~1H NMR谱、差热分析、溶解度等方法对配合物进行了表征,确定Ln_2L_3P_2·nH_2O为双核结构(L为四齿配体,P为二齿配体)。  相似文献   

8.
由具有2位氢的3-氨基-2-烯丙亚胺与N-氯或N-溴琥珀酰亚胺以甲苯作溶剂在常温下反应,制备了-些未见文献报道的2-氯和2-溴-3-氨基-2-烯丙亚胺,化合物结构均经元素分析,^1H NMR,^13C NMR和MS确证。  相似文献   

9.
赵振华 《合成化学》2003,11(5):427-430
研究了负载ZnCl2的固体催化剂在2,3-二甲基-2-丁烯与乙酐酰化合成3,3,4-三甲基-4-戊烯-2-酮反应中的催化活性。结果表明,K10粘土是最好的载体,但是HY沸石、Synclyst S13(一种无定型的酸性固体)、硅胶和氧化铝也都是制备负载ZnCl2的固体催化剂的有效载体。ZnCl2的负载量和改性方法都影响负载ZnCl2的固体催化剂的催化活性。  相似文献   

10.
呋喃酚经醚化、傅克酰化、α-溴代、噻唑环化和亚胺化等反应合成了16种4-(7-甲氧基-2,2-二甲基-2,3-二氢苯并呋喃-5-基)-2-苄亚氨基噻唑新化合物.化合物的结构经1H NMR、质谱和元素分析等确证.杀虫活性实验结果表明,化合物2a和2i在500 mg/L对棉红蜘蛛死亡率分别为53.10%和67.71%,杀菌活性实验结果表明,化合物2a和2k在25 mg/L对油菜菌核病菌抑制率分别为57.9%和59.8%,除草活性实验结果表明,2l在2250 g.ai/ha浓度下对苘麻、刺苋、藜具有一定的除草活性.  相似文献   

11.
痕量镉的催化动力学荧光分析法   总被引:1,自引:1,他引:0  
Guilbault等曾捉及利用Cd(Ⅱ)对酶催化非荧光物质高香草酸氧化为强荧光化合物反应的抑制作用可测定镉,但迄今尚未见利用催化动力学荧光分析法测定痕量镉的报道,本文拟利用Cd(Ⅱ)和咪唑对Co(Ⅲ)-T(4-SP)P络合物生成反应的催化作用,建立痕量镉的催化动力学荧光分析法。  相似文献   

12.
Design and synthesis of effective antagonists of substance P   总被引:4,自引:0,他引:4  
The agonist/antagonist activities of four background analogs of substance P (SP) facilitated design and synthesis of 12 new analogs to achieve effective antagonists. (D-Pro2, D-Phe7, D-Trp9)-SP, (D-Pro2, D-Trp7,9)-SP and (D-Arg1, D-Phe7, D-Trp9)-SP showed no agonist activity; 9 analogs showed weak agonist activity of SP. (D-Pro2, D-Trp7,9)-SP was the most potent antagonist which at a concentration of 10(-5) required a 3-fold increase in SP to allow a 50% response by SP. (D-Pro2, Lys6, D-Phe7)-SP and (D-Pro2, D-pClPhe7, D-Trp9)-SP were also potent, and the antagonism was competitive. For specific pairs of peptides, Lys6 is a promising substituent. D-Trp7,9 was as effective as Lys6, D-Phe7. D-pClPhe7 was three times as effective as D-Phe7. D-Dln6 was 1.33-fold better than D-Gln5. D-Pro2 and D-Pro4 were equally effective. D-Pro2 was 1.5 times as effective as D-Lys3. D-Pro2 may not be important. D-pClPhe9 and D-Trp9 were equally effective.  相似文献   

13.
This study focused on further analysis of the aggregation behavior of pradimicin derivatives and their interaction with cations in aqueous solution. BMY was compared with two other pradimicin antibiotics (T2 and FB) with the same aglycone moiety but consisting of different substitute groups. The surface tension measurement showed a clear critical micelle concentration at 1-2 mM of the BMY aqueous solution. The role of Zn2+ in replacing the Ca2+ was examined using 1H nuclear magnetic resonance (NMR) method. From changes in the NMR spectrum and precipitability, it was concluded that zinc ion has lower affinity and higher precipitating ability to BMY than the divalent cations of alkaline earth metal. The aggregation behavior of T2 and FB in aqueous solution was also studied using NMR method. The results suggest that the supramolecular behavior of T2 is similar to BMY whether or not Ca2+ ions are present in solution and that there are two binding sites for calcium ions in a T2 molecule. Unlike BMY and T2, the NMR spectrum of FB does not show distinct change upon Ca2+ addition. The interaction of pradimicin antibiotics with divalent metal ions was thought to be related to ionic electronegativity and to the amphoteric property of the antibiotics.  相似文献   

14.
谭福能  何媛媛  隋卫平 《应用化学》2014,31(12):1399-1404
将壳聚糖改性为(2-羟基-3-丁氧基)丙基 羟丙基壳聚糖(2-H-3-B-P-HPCS),并以(2-羟基-3-丁氧基)丙基-羟丙基壳聚糖和聚乙二醇(PEG)为原料制备(2-羟基-3-丁氧基)丙基-羟丙基壳聚糖/聚乙二醇互穿网络凝胶,研究了(2-羟基-3-丁氧基)丙基-羟丙基壳聚糖浓度、聚乙二醇的用量、交联剂戊二醛用量、反应温度对该凝胶溶胀性能的影响。 通过红外光谱分析和扫描电子显微镜的方法比较了壳聚糖、(2-羟基-3-丁氧基)丙基-羟丙基壳聚糖和(2-羟基-3-丁氧基)丙基-羟丙基壳聚糖/聚乙二醇互穿网络凝胶结构和形态上的不同。 以阿昔洛韦为模型药物研究了其释药性能。 结果表明,该凝胶均具有良好的溶胀性、pH敏感性和药物缓释作用,有望用作新型的药物载体。  相似文献   

15.
5-Hydroxymethyl-1,2-dihydropyrrolizines were catalytically hydrogenated to 3(5)-hydroxymethylpyrrolizidines, and the ratios of the isomers in the products of the reaction, which proceeds stereoselectively, were determined. The configuration of the diastereomers was established on the basis of the results of catalytic isomerization, a study of the chromatographic behavior of the isomers on a polar stationary phase, and a discussion of the isomeric composition of the hydrogenation products in the light of the general principles of the stereochemistry of catalytic hydrogenation. trans- and cis-3,8-H-3-Hydroxymethylpyrrolizidine and trans-3,8-H-3-methyl-trans-5,8-H-5-hydroxymethylpyrrolizidine were isolated from the mixtures of isomers. The existence of an intramolecular hydrogen bond in trans-3,8-H-3-hydroxymethyl- and trans-3,8-H-3-methyl-trans-5,8-H-5-hydroxymethylpyrrolizidine was shown by IR spectroscopy.See [1] for communication XIITranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 484–489, April, 1976.  相似文献   

16.
Zhu M  Huang X  Liu L  Shen H 《Talanta》1997,44(8):1407-1412
A new hydrogen donor for peroxidase, Eriochrome black T, was reported for the first time. Steady-state catalytic velocity depends upon enzyme and substrate concentrations, and a Michaelis-Menten K(m) value of 1.72x10(-5) mol l(-1) and a V(max) value of 4.43x10(-3) s(-1) were measured at pH 8.6. Trace amount of hydrogen peroxide (2x10(-7)-1.0x10(-5) mol l(-1)) was determined in aqueous solution by using the cleavage of Eriochrome black T catalyzed by peroxidase. The method is simple and practical, with high sensitivity and enzymatic activity.  相似文献   

17.
Summary The simultaneous stereospecific assay of four stereoisomers of diltiazem hydrochloride in bulk drug and aqueous solution was developed using HPLC on a Chiralcel OF column. The four isomers were quantitated with good precision by the internal standard method. The chiral inversion of (+)-cis-diltiazem hydrochloride in vitro, stability of its (2S, 3S) configuration in the solid and aqueous states was examined by HPLC. Chiral inversion of (+)-cis-diltiazem hydrochloride was not observed in the solid state, and its (2S, 3S) configuration was stable to heat, humidity and light. Chiral inversion of (+)-cis-diltiazem hydrochloride (2S, 3S) was observed in aqueous solution under UV, but not in aqueous solution stored at 80°C for 5 h nor under visible light for 10 h. The (+)-cis-diltiazem hydrochloride (2S, 3S) epimerized to (+)-trans-diltiazem hydrochloride (2R, 3S) with a half-life of 5 h in aqueous solution under UV but the reverse chiral inversion of (+)-trans-diltiazem hydrochloride (2R, 3S) to (+)-cis-diltiazem hydrochloride (2S, 3S) was not observed.  相似文献   

18.
Summary The simultaneous stereospecific assay of four stereoisomers of diltiazem hydrochloride in bulk drug and aqueous solution was developed using HPLC on a Chiralcel OF column. The four isomers were quantitated with good precision by the internal standard method. The chiral inversion of (+)-cis-diltiazem hydrochloride in vitro, stability of its (2S, 3S) configuration in the solid and aqueous states was examined by HPLC. Chiral inversion of (+)-cis-diltiazem hydrochloride was not observed in the solid state, and its (2S, 3S) configuration was stable to heat, humidity and light. Chiral inversion of (+)-cis-diltiazem hydrochloride (2S, 3S) was observed in aqueous solution under UV, but not in aqueous solution stored at 80°C for 5h nor under visible light for 10 h. The (+)-cis-diltiazem hydrochloride (2S, 3S) epimerized to (+)-trans-diltiazem hydrochloride (2R, 3S) with a half-life of 5h in aqueous solution under UV but the reverse chiral inversion of (+)-trans-diltiazem hydrochloride (2R, 3S) to (+)-cis-diltiazem hydrochloride (2S, 3S) was not observed.  相似文献   

19.
Self-stacking of four DNA bases, adenine (A), cytosine (C), guanine (G) and thymine (T), and their cross-stacking with (5,5) as well as (10,0) single walled carbon nanotubes (SWCNTs) were extensively investigated with a novel hybrid DFT method, MPWB1K/cc-pVDZ. The binding energies were further corrected with MP2/6-311++G(d,p) method in both gas phase and aqueous solution, where the solvent effects were included with conductor-like polarized continuum model (CPCM) model and UAHF radii. The strongest self-stacking of G and A takes displaced anti-parallel configuration, but un-displaced or "eclipsed" anti-parallel configuration is the most stable for C and T. In gas phase the self-stacking of nucleobases decreases in the sequence G>A>C>T, while because of quite different solvent effects their self-stacking in aqueous solution exhibits a distinct sequence A>G>T>C. For a given base, cross-stacking is stronger than self-stacking in both gas phase and aqueous solution. Binding energy for cross-stacking in gas phase varies as G>A>T>C for both (10,0) and (5,5) SWCNTs, and the binding of four nucleobases to (10,0) is slightly stronger than to (5,5) SWCNT by a range of 0.1-0.5 kcal/mol. The cross-stacking in aqueous solution varies differently from that gas phase: A>G>T>C for (10,0) SWCNT and G>A>T>C for (5,5) SWCNT. It is suggested that the ability of nucleobases to disperse SWCNT depends on relative strength [Formula: see text] of self-stacking and cross-stacking with SWCNT in aqueous solution. Of the four investigated nucleobases thymine (T) exhibits the highest [Formula: see text] which can well explain the experimental finding that T more efficiently functionalizes SWCNT than C and A.  相似文献   

20.
The reactivity of the bridged chloroborylene complex [mu-BCl((eta(5)-C(5)H(4)Me)Mn(CO)(2))(2)] (1) toward pyridine was investigated under various conditions. In the presence of protic reagents such as H[Co(CO)(4)] or H[BF(4)], the formation of the aminoborylene complex [1-(mu-B)-4-H-(NC(5)H(5))((C(5)H(4)Me)Mn(CO)(2))(2)] (2) was observed. Compound 2 represents the product of an unprecedented formal 1,4-hydroboration of pyridine. Corresponding reactions of 1 with pyridine and Tl[PF(6)] afforded 2 in similar yields, thus providing evidence that the abstraction of the boron bound chloride initiates the observed reaction. Complex 2 was fully characterized in solution and in the crystal.  相似文献   

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