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1.
The synthesis of derivatives of 3-β-D-xylopyranosyl-1,2,4-oxadiazolesis accomplished by condensing protected β-D-xylopyranosyl amidoxime with acidanhydrides or various substituted benzoyl chlorides in good yield.Thestructures of now derivatives were identified by spectra and elemental analysis.The stability of 1,2,4-oxadiazole ring and mechanism of cyclization were.investigated.  相似文献   

2.
3-Acetyltropolone was reacted with 2-aminobenzaldehydes to afford 3-(2-quinolyl)tropolones.2-Acetyl-7-methylaminotropone and 2-acetyl-7-ethylamino-tropone were respectively reacted with 2-aminobenzaldehydes to give the corres-ponding 2-(2-quinolyl)-7-methylaminotropones and 2-(2-quinolyl)-7-ethylaminotro-pones,which after treatment with sodium hydroxide solution also afforded 3-(2-quinolyl)tropolones.  相似文献   

3.
<正> C10H12Cl2N20, Mr = 247. 12, monoclinic space group P21/c, a= 7.930(2),b = 8.090(1), c=17. 950(3)A ,β=98.97(1)°, V = 1137. 5(3)A3, Z = 4, Dc=1. 443gcm-3, MoKa radiation λ=0. 71069, μ= 0. 546mm-1, F(000) = 512, R = 0. 040 for 1491 observed reflections. The conformation of the five-mem-bered ring is half-chair. The lone pair of electrons on atom N (1) is clearly nucle-ophilic.  相似文献   

4.
Two oxetane-derived monomers, 3-(2-cyano-ethoxy)methyl- and 3-(methoxy-(triethylenoxy))methyl-3'-methyloxetane (COX and MTOX), were prepared from 3-hydroxymethyl-3'-methyloxetane. Their homo- and co-polymerization in solution were carried out by the cationic ring-opening polymerization with BF3·Et2O and 1,4-butanediol as co-initiator. The molecular weight and molecular weight distribution were determined using GPC so as to reveal the competition and interchange between active chain end (ACE) and activated monomer (AM) mechanism in the process. The reactivity ratios of the two monomers were calculated according to Kelen-Tudos using 1H-NMR analysis. The influence of functional side chains in the monomers on the copolymerization behaviors was discussed in virtue of the reactivity ratio data. When doped with lithium salt LiTFSI, the ion conductivity of the homopolymer of MTOX reached 10-3.58 S/cm at 30℃and 10-2.73 S/sm at 80℃, respectively, showing its potential to be used as polymer electrolyte for lithium ion battery.  相似文献   

5.
<正> 2 - acetyldiferrocenylmethane, C5H5FeC5H4CH2C5H3 (COCH3) FeC5H5 ( I ),Mr=426. 1,violet-red prism-like crystal,m. p. 163. 7~166. 3℃,obtained from benzene-ligroin solution (benzene : ligroin=1 : 3). A crystal of approximate dimensions 0. 20×0. 40×0. 45 mm was selected for data collection from a CAD4 diffractometer with graphite monochromated MoKa radiation (λ=0. 71069A). Compound Ⅰ crystallized in the triclinic space group P1 with unit cell dimensions;a = 9. 597(2),b=9. 768 (2),c=11.540(1) A ,α= 111-93(1),β=111. 42(1),γ= 92. 46(2)°,V = 913. 9 A3, Z= 2, and Dc= 1. 548 g/cm3. 3' - Acetyldiferrocenylmethane, C5H5FeC5H4CH2C5H4FeC5 H4-COCH3(Ⅱ) ,is an isomer of compound Ⅰ ,yellow needle-like crystal,m. p. 110. 5~ 111. 0℃ ,obtained by the same method. A crystal of approximate dimensions 0. 025×0. 01×0. 45 mm was selected for data collection. Compound Ⅱ crystallized in monoclinic space group P21/c with a = 10. 930 (2), b= 5. 907(6) ,c= 27. 729(5) A ,β= 92. 64 (1)°,V=1788. 4A3,Z=4,Dc=1. 583 g/cm3.  相似文献   

6.
 Two oxetane-derived monomers, 3-(2-cyano-ethoxy)methyl- and 3-(methoxy-(triethylenoxy))methyl-3′-methyloxetane (COX and MTOX), were prepared from 3-hydroxymethyl-3-methyloxetane. Their homo- and co-polymerization in solution were carried out by the cationic ring-opening polymerization with BF3•Et2O and 1,4-butanediol as co-initiator. The molecular weight and molecular weight distribution were determined using GPC so as to reveal the competition and interchange between active chain end (ACE) and activated monomer (AM) mechanism in the process. The reactivity ratios of the two monomers were calculated according to Kelen-Tudos using 1H-NMR analysis. The influence of functional side chains in the monomers on the copolymerization behaviors was discussed in virtue of the reactivity ratio data. When doped with lithium salt LiTFSI, the ion conductivity of the homopolymer of MTOX reached 10-3.58 S/cm at 30℃ and  10-2.73 S/cm at 80℃, respectively, showing its potential to be used as polymer electrolyte for lithium ion battery.  相似文献   

7.
DIRECTCONVERSIONOF3-ACETOXYBENZOFURANSTO3-METHOXYBENZOFURANS¥ZhiMinWANG;XiaoTianLIANGandShuFengCHEN(InstituteofMateriaMedica,...  相似文献   

8.
Fractions of a water insoluble α-(1→3)-D-glucan (GL) extracted from Ganoderma lucidum were carboxy-methylated (CM) to obtain water-soluble carboxymethylated derivatives (CM-GL) having a degree of substitution (DS) of0.38~0.51. Weight-average molecular weight M_w and intrinsic viscosity [η] of the samples CM-GL were measured by gelpermeation chromatography combined with laser light scattering (GPC-LLS) and viscometry. The CM-GL exhibits a stifferchain in aqueous solution at 25℃ than the original glucan, The antitumor activities against Ehrlich ascites carcinoma (EAC,5×10~6) of the carboxymethylated derivatives from the α-glucan and curdlan, a β-glucan, are significantly higher than thoseof the original glucans. The effects of the relatively low molecular weight, expanded chains and better water-solubility of theCM-GL on the enhancement of antitumor activity could not be neglected. The chain stiffness decreased speedily withincrease of temperature from 40 to 60℃ or NaOH concentration from 0.1 to 0.4 in the solution, respectively, and the changeof the chain stiffness is reversible.  相似文献   

9.
This paper deals with the synthesis of the 3'-half molecule of yeast alanine transfer RNA (tRNA_y~(Ala)) by ligation with T_4 RNA ligase of three component oligonucleotide fragments corresponding to nucleotides 36-45(Ⅰ), 46-57(Ⅱ) and 58-76(Ⅲ) in succession extending from the 3'-end to the 5'-end. First, in a ratio of acceptor to donor at 1.5 to 1, we adopted a method of three successive reactions, namely, the 5'-phosphorylation of the nonadecamer (Ⅲ), ligation with the dodecamer(Ⅱ) and the 5'-phosphorylation of the ligation product formed; with one isolation step and obtained the 5'-phosphorylated 31mer(46-76) (Ⅳ) in an overall yield of 70%. Then the 31met(Ⅵ) as a donor was ligated with 3 times of decamer(Ⅰ) to form the 41met(36-76) (Ⅴ), the 3'-half molecule of tRNA_y~(Ala)). The yield was 67%. After 5'-phosphorylation, (Ⅴ) was ligated with the natural 5'-half molecule to form the semi-synthetic tRNA_y~(Ala)), which was biologically active, i. e. accepting and transferring (~3H)-alanine into p  相似文献   

10.
STUDIES ON THE SYNTHESIS OF TRACHYLOBAGIBBERELLINANALOGUE(Ⅱ)SYNTHESIS OF DIMETHYLESTER OF 3-HYDROXY-△1_10-12,16-CYCLOGIBBEREL?..  相似文献   

11.
《合成通讯》2013,43(2):305-314
ABSTRACT

The selective synthesis of ethyl 4-(diethoxyphosphinyl)-3-oxobutanoate (7) and the utilization of its trimethylsilyl enolether (14) in a tandem desilylation Horner-Wittig condensation is illustrated.  相似文献   

12.
SYNTHESISOFCF_3-SUBSTITUTEDENEDIYNESSYNTHESISOFCF_3-SUBSTITUTEDENEDIYNES¥FengHONGandChangMingHU(ShanghaiInstituteofOrganicChe...  相似文献   

13.
SYNTHESIS OF ANALOGUES OF HUPERZINE A 3.THE PREPARATION OF SOME SINGLE RING ANALOGUES OF HUPERZINE A ¥(BaoGenWU;WeiPinZHEN;Yu...  相似文献   

14.
Preparation and characteriration of bimetallic Pd-Fe/Al_2O_3 catalysts—Characterization by infrared spectroscopy and X-ray diffraction……………………………………………………XIAO,T.C.;AN,L.D.;TANG,A.H.;XU,X.L.(1)Preparation and characterization of bimetallic Pd-Fe/Al_2O_3 catalysts-Characterization by TEM,EDX,XPS and ESR…………………………XIAO,T.C.;AN,L.D.;TANG,A.H.;LI,S.L.;XU,X.L.(13)Effect of phosphorus addition to ZrO_2/SiO_2 on catalytic properties for dehydrogenation ofmethanol…………………………………………………………ZHANG,F.X.;MA,J.;XU,P.P.(24)Study of TPD and kinetics on NO+CO over copper-substrate catalysts……………………………………………………………………………………LU,G.Z.;WANG,R.(35)Effect of pelleting pressures on global reaction rates of methanol synthesis over CU-basedcatalyst……YAO,P.F.;LIU,G.J.;ZHU,B.C.(44)Selective oxidation of propane over α-Bi_2Mo_3O_(12)/MoO_3catalyst……WU.T.H.;YU,J.F.;YANG,H.M.;WAN,G.J.;JIANG,Y.Z.LI,Y.G.(53)Activity and selectivity of ruthenium carbonyl,ke  相似文献   

15.
Two tetrameric arabinogalactans, β-D-galactopyranosyl-(1→6)-β-D-galactopyranosyl-(1→6)-[α-L-arabinofuranosyl-(1→3)]-D-galactopyranose (14) and α-L-arabinofuranosyl-(1→3)-β-D-galactopyranosyl-(1→6)-β-D-galactopyranosyl-(1→6)-D-galactopyranose (25), which are good candidates for CCRC-M7 epitope characterization, were synthesized efficiently using a convergent strategy. Migration of an acceptor acetyl group proved to be an obstacle to synthesis, but regioselective glycosylation or 4-O-benzyl protection of the acceptor circumvented this problem allowing efficient synthesis of the 1→6 linked target compounds.  相似文献   

16.
PROPERTYOFAlF3CATALYSTSPREPAREDBYFLUORINATIONOFAl2O3WITHHFLüJian*,ShiLei,YangHui′e,ChenShukang,RenJiangang,LiHuili,PengShaoyi...  相似文献   

17.
3-Butylidene-5-hydroxyphthalide(1)was prepared from 4-hydroxy-benzoic acid(2).  相似文献   

18.
于建 《高分子科学》2004,(6):573-579
The encapsulation of stearic acid coated nanometer CaCO3 by a polystyrene (PS) network via emulsion polymerization is described, where γ-methacryloxypropyltrimethoxysilane (MPS) was used as an efficient crosslinker. The important factors such as the type and amount of surfactant and initiator and the content of CaCO3 are investigated as well as the role of MPS. It has been shown that little PS was extractable with only 0.6 wt% of MPS (relative to styrene). The cationic surfactant cetyl trimethylammonium bromide (CTAB) proved more effective than the anionic surfactant sodium dodecyl sulfonate (SDS). The yield rises, particles become smaller and size distribution broadens with increased amount of CTAB. It is also found that either 2,2′-azobis(isobutyronitrile) (AIBN) or ammonium persulfate (APS) is suitable for attaining high monomer conversion. With increased amount of CaCO3, the encapsulation ratio can be varied from 17.9 to 3.6, while monomer conversion and yield decrease slightly. FT-IR spectra of the products after extraction indicate tight encapsulation between PS and CaCO3, and TEM photographs of composite particles with well-defined core-shell structure give direct evidence of encapsulation.  相似文献   

19.
Keeping in view the biological activities of 3-hydroxyisoxa-zole and cyclic phosphate derivatives,some compounds possessing thesetwo moieties have been synthesized,the structural elucidation ofthese diastereomers was made depending on spectral analyses.Themechanism could be illustrated by the theories of trigonal bipyramideintermediate and pseudorotation.  相似文献   

20.
The Rat 3-3 is a secondary transformant of the rat fibroblast cell line (Rat-1) transfectedwith total DNA of a gastrocarcinoma cell line BGC-823. The cells over-express the c-Ha-rasoncogene which contains point mutation at the 12th codon. In order to determine how theactivated c-Ha-ras oncogene expression governs the cell's transformation, two pendadecadeoxy-nucleotides AS-1 and AS-2 were synthesized. AS-1 was complementary to the single strandof the first three codons and the upstream sequence close to the ribosome binding site of c-Ha-ras mRNA. AS-2 was complementary to the 3' end of the first intron and the 5' end ofthe second exon of c-Ha-ras unripe RNA enclosed in the nucleus. The oligonucleotides couldblock either the translation of c-Ha-ras mRNA or the splicing of c-Ha-ras unripe RNA, thusinhibiting the expression of the activated c-Ha-ras oncogene and the proliferation of thetransformed cells Rat 3-3. The inhibitory effect increased with a growing concentration ofthe antisense oligodeoxynucleoti  相似文献   

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