3-(2-二唑啉基)-色酮类化合物的合成研究

报道了取代的邻羟基苯乙酮(1a～1e)经Vilsmeier-Haack反应一步制得3-醛基色酮(2a～2e),2a～2e与取代的芳酰肼(3a～3c)缩合制得15个酰腙类化合物(4a～4o),4a～4o在醋酸酐作用下关环得15个3-(2-苝二唑啉基)-色酮(5a～5o),并通过元素分析,IR,~1H NMR和MS诺数据确证了上述化合物的结构。     

3-(2-卓二唑啉基) - 色酮类化合物的合成研究

报道了取代的邻羟基苯乙酮(1a～1e)经Vilsmeier-Haack反应一步制得3－醛基色酮(2a～2e),2a～2e与取代的芳酰肼(3a～3c)缩合制得15个酰腙类化合物(4a～4o),4a～4o在醋酸酐作用下关环得15个3-(2-卓二唑啉基)-色酮(5a～5o),并通过元素分析,IR,^1^HNMR和MS谱数据确证了上述化合物的结构。     

酰氨基硫脲及相关杂环衍生物的研究XXIX: 2-(3'-溴苯胺基)-5-[5'-氨基-1'-(4"-氯苯基)-1',2',3'-三唑-4'-基]-1,3,4-噻二唑的晶体结构

经1-[5'-氨基-1'-(4"-氯苯基)-1',2',3'-三唑-4'-甲酰基]-4-(3'-溴苯基)-3-氨基硫脲在浓硫酸作用下制得2-(3'-溴苯胺基)-5-[5'-氨基-1'-(4"-氯苯基)-1',2',3'-三唑-4'-基]-1,3,4-噻二唑化合物。该化合物的晶体结构经X射线衍射分析确定, 化合物属三斜晶系, P1空间群, a=1.1784(2), b=1.4455(2),c=1.1353(1)nm; α=100.68(1), β=109.50(1), γ=79.89(1)°; V=1.7779nm^3; 分子式C~1~6H~1~1BrClN~7S, Mr=448.75; Dc=1.673g/cm^3, Z=4,μ=58.16cm^-^1, 最终偏离因子R=0.084, Rw=0.086。分析化合物的键长, 键角数据表明, 该分子具有离域π键结构。     

Trinuclear copper(II) complex showing high selectivity for the hydrolysis of 2'-5' over 3'-5' for UpU and 3'-5' over 2'-5' for ApA ribonucleotides

The cooperative action of multiple Cu(II) nuclear centers is shown to be effective and selective in the hydrolysis of 2'-5' and 3'-5' ribonucleotides. Reported herein is the specific catalysis by two trinuclear Cu(II) complexes of L3A and L3B. Pseudo first-order kinetic studies reveal that the L3A trinuclear Cu(II) complex effects hydrolysis of Up(2'-5')U with a rate constant of 28 x 10(-)(4) min(-)(1) and Up(3'-5')U with a rate constant of 0.5 x 10(-)(4) min(-)(1). The hydrolyses of Ap(3'-5')A and Ap(2'-5')A proceed with rate constants of 24 x 10(-)(4) min(-)(1) and 0.5 x 10(-)(4) min(-)(1) respectively. The L3A trinuclear Cu(II) complex demonstrates high specificity for Up(2'-5')U and Ap(3'-5')A. Similar studies with the more rigid L3B trinuclear Cu(II) complex shows no selectivity and yields lower rate constants for hydrolysis. The selectivity observed with the L3A ligand is attributed to the geometry of the ligand-bound diribonucleotide which ultimately dictates the proximity of the attacking hydroxyl and the phosphoester to a Cu(II) center for activation and subsequent hydrolysis.     

DIMER PHOTOPRODUCTS IN CYTIDYLYL-(3'-5') CYTIDINE

Abstract— When CpC is exposed to ultraviolet (u.v.) radiation, dimers are produced both photochemically and by dark reactions. A reaction scheme for the production of these dimers is presented. We have shown that a single dimer, CC₁, is initially produced photochemically. This is converted by a spontaneous reaction to a second dimer, CC₂. The dimer CC₂ may also spontaneously revert back to CC₁ and if no side reactions were involved a thermal equilibrium between these txo dimers would be established with about two to three times the concentration of CC₂, as of CC₁. The rate constants for the interconversion of these two dimers vary from about 0.05 to 0.4 hr^-1 over the pH range 2.7 to 8.4. The dimers of CpC have maximum stability near pH 7. The two dimers CC₁ and CC₂ can also be reversed to CpC by u.v. irradiation. Both these dimers in turn deaminate to dimers of UpC and then to UU. The rate constants for these deamination reactions are presented. These lie in the range 0.01 to 0.5 hr^-1 for the pH values studied. Possible structures for the two dimers are suggested.     

The photochemistry of thymidylyl-(3'-5')-5-methyl-2'-deoxycytidine in aqueous solution

The photochemistry of the dinucleoside monophosphate thymidylyl-(3'-5')-5-methyl-2'-deoxycytidine (Tpm5dC) has been studied in aqueous solution using both 254 nm and UV-B radiation. A variety of dinucleotide photoproducts containing 5-methylcytosine (m5C) have been isolated and characterized. These include two cyclobutane dimers (CBD) (the cis-syn [c,s]and trans-syn forms), a (6-4) adduct and its related Dewar isomer, and two isomers of a product in which the m5C moiety was converted into an acrylamidine. Small amounts of thymidylyl-(3'-5')-thymidine (TpT) were also formed, presumably as a secondary photoreaction product. In addition, a photoproduct was characterized in which the m5C moiety was lost, thus generating 3'-thymidylic acid esterified with 2'-deoxyribose at the 5-hydroxyl on the sugar moiety. The c,s CBD of Tpm5dC readily undergoes deamination to form the corresponding CBD of TpT. The kinetics of this deamination process has been studied; the corresponding enthalpy and entropy of activation for the reaction have been evaluated at pH 7.4 as being, respectively, 73.4 kJ/mol and -103.5 J/K mol. Deamination was not observed for the other characterized photoproducts of Tpm5dC.     

X-ray Structure of 1- (3' -Phenyl-4' -morpholinyl-2' 5' - dithiole-1' - ylidene)-3, 4-biscarboethoxy-2-thionaphthalene

1INTR0DUCTIONa-Thiocarbonylthioformamideshavebeensynthesizedsince1980[l-23,however,thereisn0reP0rtofthesecomP0undsrelatedtheirpropertiesandreactivities(3).Ac-cordingtothepublishedpapers('-",adithioketone,adithioesterandadithioth-ioesteraresnitablefort4 2JcycloadditionwithalkenicandacetylenicdienophileS.Wewanttoknowwhethera-thiocarbonylthioformamideshavethesamecharacters,thereforethereactionofathiobenzoylthioformmorpholine(1)withdiethylacetylenedicarboxylate(2)wasexplored.Theredultsshowth…     

Unusual Recyclization of 2(1-Bromostyryl)-4-oxo-1'3-benzoxazinium Perchlorate into 2'3'4'5-Tetrahydro-1'4-benzoxazepine-4'5-dione

Russian Journal of Organic Chemistry -     

螺〔1-溴-4-l-孟氧基-5-氧杂-6-氧代双环〔3.1.0〕己烷2,3’-(4’-甲氧基5’孟氧基丁内酯)〕的晶体结构

本文报道了利用新手性源合成的标题化合物C2 9H45 BrO7(Mr=5 85 .5 6 )的晶体结构 ,该晶体属正交晶系 ,空间群为P2 1 2 1 2 1 ,晶胞参数a =9.748(4) ,b =12 .5 37(5 ) ,c =2 5 .85 1(9) ,V =315 9(2 ) 3,Z =4,Dx=1.2 31g/cm3,μ =1.341mm- 1 ,F(0 0 0 ) =12 40 ,偏离因子R =0 .0 475 ,Rw=0 .0 6 0 9;分子中共有 5个环 ,12个手性中心 ,2个六元环呈椅式构象 ,2个五元内酯环呈信封式构象 ,并分别与环丙烷形成〔2 .4〕螺环和〔3 .1.0〕稠环 ,4个新生成的手性中心的绝对构型为C(13) (S) ,C(14 ) (S) ,C(15 ) (R) ,C(16 (R) ,无任何对称因素