首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
异氰酸苯醇和N-[2-(4,6-二甲基)-嘧啶基]-羟胺(5)反应生成1-[2-(4,6-二甲基)-嘧啶基]-1-羟基-3-苯基脲(6)。化合物(6)在三乙胺存在下和氯甲酸乙醇反应生成2-[2-(4,6-二甲基)-嘧啶基]-4-苯基-1,2,4-噁二唑烷-3,5-二酮(1)。  相似文献   

2.
1 INTRODUCTIONBenzoylphenyltioureas having a generalformula( ) were reported to have in secticidalactivity〔1〕,which isclosely related to theirstructures,particularly tothedi hedralangle between the- CONH- plane and phenylring〔2〕.Surprisingly there islittle reported in the literature,only three related structures stored in CSD〔3〕 until1 998.In thispaper,we reportthe crystalstructure ofthe title compound.R CONHCSNHR2 EXPERIMENTAL2 .1 Synthesis  The synthesisofthetitl…  相似文献   

3.
张自义  杨丰科 《有机化学》1994,14(5):553-557
本文首先用5-(3-吡啶)-2H-四唑乙酰基酰肼与芳酰基异硫氰酸盐反应制备成化合物1-[5-(3-吡啶)-2H-四唑乙酰基]-4-芳酰氨基硫脲化合物1a~j, 然后用冰醋酸回流处理1a~j得到一系列化合物5-[5-(3-吡啶)-2H-四唑亚甲基]-2-芳酰氨基-1,3,4-噻二唑2a~j . 化合物1a~b在强碱介质中首先发生降解, 然后进行环化反应 .  相似文献   

4.
相转移催化法合成1-O-酰基-四-O-乙酰基-β-D-吡喃己糖   总被引:10,自引:0,他引:10  
以氯化三乙基苄基铵作为相转移催化剂, 用2, 3, 4, 6-四-O-乙酰基-β-D-溴代吡喃葡萄糖和2, 3, 4, 6-四-O-乙酰基-β-D-溴代吡喃半乳糖与羧酸反应, 合成了相应的1-O-酰基-2, 3, 4, 6-四-O-乙酰基-β-D-吡喃葡萄糖和半乳糖。通过解析这些化合物的^1H NMR和红外光谱, 确证其糖甙键构型为β。该相转移催化法具有反应条件温和, 后处理简单和立体选择性强等优点。  相似文献   

5.
由苯并-15-冠-5经硝化、还原两步反应,制得4',5'-二氨基苯并-15-冠-5(2)。后者与水杨醛或其取代衍生物缩合,合成了一系列新的冠醚化双Schiff碱化合物1a~1h,经元素分析、IR、^1^HNMR和MS确证了其结构。  相似文献   

6.
采用ZORBAX Ec lipse XDB-C8(4.6 mm i.d.×150 mm,5μm)色谱柱,乙腈流动相,流速0.70 mL.m in-1,检测波长407 nm,建立了测定1-(对偶氮苯)-3-(5-氯-2-吡啶)-三氮烯的反相高效液相色谱法.该方法线性范围0.5-8.0 mg.L-1,相对标准偏差为2.5%(c=5.0 mg.L-1,n=5),回收率在95.7%-105%之间.  相似文献   

7.
The nitro group in 1-(pentafluorophenyl)-2-nitroalkanols is reduced selectively to a hydroxylamino or amino group by controlled potential electrochemical reduction. The pentafluoro-phenylaminoalkanols cyclize readily on heating in dimethylformamide to give homologs of 4,5,6,7-tetrafluoroindole. It is shown that the intermediate in the cyclization of 1-pentafluorophenyl-2-aminoethanol is 3-hydroxy-4,5,6,7-tetrafluoroindoline. Cyclization of 1-pentafluorophenyl-2-hydroxyaminoethanol gave 1,3 -dihydroxy-4,5,6,7-tetrafluoroindoline.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 5, pp. 622–625, May, 1970.  相似文献   

8.
对(4R-cis)-6-[2-[2-(4-氟苯基)-5-(1-异丙基)-3-苯基-4-[苯胺(羰基)]-^1H-吡咯-1-基]乙基]-2,2-二甲基-1,3-二氧己环-4-乙酸叔丁酯的傅里叶变换离子回旋共振质谱(FT-ICR-MS)、核磁共振氢谱(^1H-NMR)、碳谱(^13C-NMR)以及^1H同核位移相关谱(^1H-^1HCOSY)、检出^1H的异核多量子相干谱(HMQC)和^1H检测的异核多键相关谱(HMBC)报道并进行解析。确定了^1H谱、^13C谱中各谱峰的归属,研究了其六元环部分的立体构象,并就空间效应对其化学位移的影响做了初步的探讨。  相似文献   

9.
(E)-1-alkyl-4-     
(E)-1-Alkyl-4-[2-(alkylsulfonyl)-1-ethenyl]pyridinium salts were synthesized in two steps. These sulfones were stable at pH 7.3 and underwent a nucleophilic vinylic substitution (S(N)V) with mercaptans, including thiouracile, to give the corresponding 4-(thiovinyl)-pyridinium salts. The X-ray diffraction structure of (E)-1-methyl-4-[2-(ethylsulfanyl)-1-ethenyl]pyridinium iodide indicated conjugation of the sulfur with the pyridinium ring. (Z)-1-Methyl-4-[2-(methylsulfanyl)-1-ethenyl]pyridinium iodide, prepared from the corresponding thioether by reaction with methyl iodide in diethyl ether, underwent isomerization to the E isomer in a first-order reaction in deuterated [D6]DMSO with an activation energy of 14 kcalmol(-1). At pH 7, the (E)-1-methyl-4-[2-(methylsulfonyl)-1-ethenyl]pyridinium iodide (19) reacted specifically with thiols. The reaction of this sulfone with glutathione in a TES buffer at pH 7 was a second-order reaction (k = 4,100 M(-1)s(-1) at 30 degrees C) and gave the corresponding substitution product with an intense long wavelength absorption band (lambdamax=360 nm, epsilon = 27,500 M(-1)cm(-1)). The modification of different enzymes of known structure with 19 showed the high selectivity of this reagent towards thiol groups and its usefulness in the quantitative determination of free thiol groups in proteins.  相似文献   

10.
SA2572 ((+)-1), 3-acetyl-2-[5-methoxy-2-[4-[N-methyl-N-(3,4,5-trimethoxyphenethyl) amino] butoxy]phenyl]-benzothiazoline hydrochloride is a newly synthesized Ca2+ antagonist having a inhibitory effect on the fast Na+ inward channel. In order to clarify the absolute configurations and the pharmacological properties of both enantiomers, compounds ((+)-1 and (-)-1) were synthesized. The configurations of these compounds were assigned on the basis of an X-ray crystallographic analysis of synthetic precursor (5). The in vitro Ca2+ channel blocking activities of (+)-1 and (-)-1 were evaluated in terms of the inhibitory activities on depolarization-induced contraction of guinea pig taenia cecum and rabbit aorta. The in vivo efficacy of the enantiomers was evaluated with their hypotensive effects in spontaneously hypertensive rats. Compound (-)-1 showed more potent Ca2+ antagonistic activities on guinea pig taenia cecum and rabbit aorta and the hypotensive effect than those activities of (+)-1. In the electrophysiological study of Langendorff perfused rabbit hearts, compound (+)-1 showed more potent inhibitory effect on the fast Na+ inward channel than that of compound (-)-1, and an approximately equal potent inhibitory effect on the slow Ca2+ inward channel as compared with compound (-)-1. Stereoselectivity of the pharmacological activity was found.  相似文献   

11.
Highly efficient and selective syntheses of the title compounds are described. The cornerstone of the synthetic plan is the tandem inter [4 + 2]/inter [3 + 2] cycloaddition process. These syntheses differ from previous applications of this strategy in that they incorporate an alkylation in the hydrogenolysis step to close the second ring of the azabicyclic systems. Notable features of the sequence are (1) the highly regio- and stereoselective [3 + 2] cycloaddition of nitronate 15 with siloxymethyl (Z)-beta-silylvinyl ketone (Z)-22b and (2) the highly selective reduction of the resulting ketone 24a with L-Selectride. A single-crystal X-ray structure analysis of synthetic (-)-7-epiaustraline confirmed that the targeted structure was successfully synthesized. This stimulated a reexamination of the structural assignment of the natural product. (-)-1-Epicastanospermine was synthesized in four steps from the common intermediate 27a. The absolute configuration of (-)-1-epicastanospermine was assured by single-crystal X-ray structure analysis of intermediate (-)-27a. Thus, the sign of the optical rotation had to be revised. The overall efficiency of these syntheses were 9 steps and 23% yield for (-)-7-epiaustraline and 10 steps and 20% yield for (-)-1-epicastanospermine  相似文献   

12.
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。  相似文献   

13.
本文给出了一条较好的制备7,8-二氢-6,6-二甲基-7,8环氧-6氢-吡喃[2,3-f]苯并-2,1,3-噁二唑的合成路线,即由对乙酰氨基苯酚经酯化、Fries重排、环合、还原、脱水、硝化、脱酰基、氧化、脱氧和催化环氧化等反应制得标题化合物,其结构经元素分析和光谱数据确证。  相似文献   

14.
Bromination of 1-(4-hydroxyphenyl)dihydrouracil and its 6-methyl derivative with bromine in refluxing acetic acid gave 1-(3,5-dibromo-4-hydroxyphenyl)-5-bromo-, 1-(3,5-dibromo-4-hydroxyphenyl)-5-bromo-, and 1-(3,5-dibromo-4-hydroxyphenyl)-5-bromo-6-methyldihydrouracils and 1-(3,5-dibromo-4-hydroxyphenyl)-5-methyluracil. 5-Bromo- and 5,5-dibromodihydrouracils were dehydrobrominated, and the same compounds undergo decomposition to 3,5-dibromo-4-hydroxyphenylurea upon alkaline hydrolysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1251–1254, September, 1982.  相似文献   

15.
16.
《Tetrahedron》1986,42(21):5985-5990
The title compounds, 1 and 1', are readily available in four steps from 2-benzyloxymethyl-2-propen-1-ol, the key step being Sharpless asymmetric epoxidation to give the chiral epoxides 5 or 5'. The total chemical yield of 1 or 1' is 50%, the final products being obtained essentially optically pure. By suitable protecting group manipulation, both title enantiomers can be produced from either of the antipodal epoxides 5 or 5'.  相似文献   

17.
(S)-2-氨基-1,1-二苯基-1-丙醇是一种合成多种手性助剂的重要中间体,也用于外消旋屈昔多巴前体化合物的拆分。从价廉易得的L-丙氨酸出发,通过四步反应制得,总收率55.6%L-丙氨酸经甲酯化,苄氧羰基保护制得的L-2-苄羰基氨基丙酸甲酯与苯基溴化镁反应制得(S)-2-苄氧羰基氨基-1,1-二苯基-1-丙醇。是在5%Pd/C催化加氢下脱除苄氧羰基得到标题化合物。该制备方法涉及的中间体及目标化合物易于纯化,总收率高且重现性好。我们用制得的氨基醇能成功地拆分外消旋苏式屈昔多巴前体化合物3-3,4-二苄氧苯基)-N-苄氧羰基丙氨酸。  相似文献   

18.
Summary Two 1,2,3-triazole anticonvulsants, 1-(4-methylsulfone-phenyl)-5-(4-fluoro-phenyl)-5-[14C]-1,2,3-triazole and 1-(4-sulfonamide-phenyl)-5-(4-fluoro-phenyl)-5-[14C]-1,2,3-triazole, both labeled with carbon-14 in the 5-position were prepared from para-fluoro-benzonitrile-[cyano-14C].  相似文献   

19.
在DMF溶剂中,不外加催化剂使邻取代芳香醛(1)与5,5-二甲基-1,3-环己三酮(2)发生缩合和加成反应生成3,3,6,6-四甲基-4a-羟基-9-芳基-1,8二氧化-2,3,4,4a,5,6,7,8,9a-十氢化-1H氧杂蒽(3a~3d)。在同样条件下,邻羟基芳香醛与5,5-二甲基-1,3-环己三酮则发生缩合,加成和脱水反应生成3,3-二甲基-9-(5,5-二甲基-3-羟基-2-环己烯-1-酮-2-基)-1-氧代-2,3,4,9-四氢化-1 氧杂蒽(4a~4b)。用单晶X-射线分析法确定了产物3a和4a的晶体结构。  相似文献   

20.
《Polyhedron》1987,6(5):1059-1064
The reactions of palladium(II) chloride with 1,4 - diphenyl - 2,3 - dimethyl - 1,4 - diazabutadiene and 1,4 - di(p - methoxyphenyl) - 2,3 - dimethyl - 1,4 - diazabutadiene are described. With 1,4 - diphenyl - 2,3 - dimethyl - 1,4 - diazabutadiene diimine fission is produced, giving rise to a product identified by elemental analysis, IR and Raman spectra, and X-ray diffraction, as trans-dichlorobis(aniline) palladium(II). The complex is soluble in dimethylformamide and crystallizes with two molecules of solvent. The substance crystallizes in the monoclinic space group P21/n. The X-ray data were refined to R = 0.047 and Rw = 0.046. Final distances are PdN = 2.060(5)Åand PdC1 = 2.299(2)Å. There are two bifurcated intermolecular NH ... C1 and CH... C1 hydrogen bonds which, together with one more intermolecular hydrogen bond NH... O, are responsible for the packing of the molecules. However, when 1,4 - di(p - methoxyphenyl) - 2,3 - dimethyl - 1,4 - diazabutadiene was treated with palladium chloride under the same conditions cis - dichloro - 1,4 - di(p - methoxyphenyl) - 2,3 - dimethyl - 1,4 - diazabutadiene was formed, as deduced from elemental analysis, and IR and Raman spectra.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号