β-二酮镧系元素络合物热行为的研究

本文用差热分析(DTA)、热重法(TG)、微商热重法(DTG)研究了十二种三价镧系金属离子与1,1,1,2,2,3,3七氟-7,7,二甲基-4,6辛二酮的络合物Ln(fod)_3·mH_2O的脱水过程和热分解过程的动力学。其脱水反应发生在100℃附近。络合物最大热分解速率的温度和热分解反应活化能均随中心金属原子——镧系元素原子序变化,呈现“双峰”现象。     

Preparation and catalytic hydrogenation of 4,6-dimethyl- and 4,7-dimethyl-8-methoxycoumarins. A 4-methyldihydrocoumarin synthesis

Reduction of the title coumarins at 1500 psi and 150° over 10% palladium on charcoal provides a simple route to dihydrocoumarins and/or ethyl butanoates, hydrogenolysis products of the lactone. Lower pressures and temperatures tend to yield only the dihydrocoumarin. The butanoates are readily converted to the dihydrocoumarins in polyphosphoric acid.     

A novel synthesis of 4,6-dimethyl- and diphenyl-2,5-dihydro-1,3,5,2-triazaphosphorines

The synthesis of 2,5-dihydro-1,3,5,2-triazaphosphorines via the intramolecular cyclization of N,N'-phos-phinylacetamidines or benzamidines is described. These derivatives represent the sole examples of 4,6-dialkyl or diaryl substitutions of this ring system.     

2-羟基-4,6-二甲基嘧啶盐酸盐制备方法的改进

针对目前文献中报道的2-羟基-4,6-二甲基嘧啶盐酸盐的合成存在加料繁琐、收率低等问题,我们在合成时对加料方式、反应过程、产物分离三方面做了改进,简化了加料过程,相同条件下收率提高了10%。对改进后的方法进行了参数优化,65℃时反应48h收率达91.3%。     

The reaction of fullerene C(60) with 4,6-dimethyl-1,2,3-triazine: formation of an open-cage fullerene derivative.

A thermal reaction of fullerene C(60) with 4,6-dimethyl-1,2,3-triazine (4) in o-dichlorobenzene gave azacyclohexadiene-fused fullerene derivative 5, by the reaction with intermediate azete 11, and then, after flash chromatography over SiO(2), open-cage fullerene derivative 6 having an eight-membered ring orifice on the C(60) cage. Compound 6 is assumed to be formed via addition of diradical intermediate 13 to C(60). Compound 6 underwent a further photochemical reaction with singlet oxygen with the cleavage of one of the double bonds at the rim of the orifice to afford triketone derivative 8 having a 12-membered ring orifice.     

A convenient method for the synthesis of substituted 2-alkylthio-3-cyano-4,6-dimethyl-5-phenylcarbamoyl-1,4-dihydropyridines

Substituted 2-alkylthio-3-cyano-4,6-dimethyl-5-phenylcarbamoyl-1,4-dihydropyridines were obtained by successive reaction of acetaldehyde with cyanothioacetamide and acetoacetanilide, -chloracetamide or phenacyl bromide in the presence of piperidine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 345–347, March, 2000.     

The electrochemical oxidation of ammonia at boron-doped diamond electrodes exhibits analytically useful signals in aqueous solutions

Boron-doped diamond electrodes are shown to exhibit well-defined analytically useful voltammetric signals for the electrochemical oxidation of ammonia in aqueous solutions in comparison to commonly used carbon based electrode substrates. Proof-of-concept is shown for the construction of a miniature amperometric ammonia gas sensor utilising conductive boron-doped diamond.     

Azidomethyl-ruthenocene: facile synthesis of a useful metallocene derivative and its application in the 'click' labelling of biomolecules

A convenient synthesis of azidomethyl-ruthenocene and its use in the covalent labelling of amino acids, peptides and a peptide nucleic acid (PNA) monomer derivative by Cu(I) catalyzed azide-alkyne coupling (Cu-AAC, "click chemistry") are described.     

A facile synthesis of fused spiroketal skeleton: 2,2′-spirobi(4-aryl-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydrochroman)

A one-pot synthesis of fused spiroketal skeleton, 2,2′-spirobi(4-aryl-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydrochroman) 4a-c, has been achieved for the first time by an application of Michael reaction between dimedone (5,5-dimethylcyclohexan-1,3-dione) 1 and trans,trans-diarylideneacetone (1,5-diaryl-1,4-pentadien-3-one) 2 using anhydrous ZnCl₂ as catalyst. The spiroketalization was achieved efficiently via intramolecular cyclization of the Michael 1:2 adduct.     

微波辐照下4-苯基-7,7-二甲基-2,5-二氧代-1,2,3,4,5,6,7,8八氢喹啉的合成和晶体结构

标题化合物C1 7H1 9NO2 是由苯甲醛、5,5 二甲基 1 ,3 环己二酮、丙二酸亚异丙酯及醋酸铵在微波辐照下干反应而得。结构通过单晶X 射线衍射法确定 ,其晶体属于单斜晶系 ,空间群P2 1 /a ,a =7.52 4 (2 ) ,b =2 2 .483(3) ,c =9.2 73(2 ) ,β =1 1 3 0 4 (2 )°,V =1 44 3.7(5) 3,Mr=2 69.34,Dc=1 .2 39g/cm3,Z =4,μ(MoKα) =0 81cm- 1 ,F(0 0 0 ) =576,在 6 <2θ <51 0°范围内收集 2 994个独立衍射点 ,其中可观测衍射点 2 0 91个 [I >2 .50σ(I) ]。晶体结构用直接法解出 ,经用全矩阵最小二乘法对原子参数进行修正 ,最后的偏离因子为R =0 .0 4 4 ,Rw=0 .0 58。在晶体结构中 ,O(3) -C(9) -C(4) -C(5) -N(1 )构成一个平面 ,该平面与苯环的二面角为 84.2 5°     

Spherical resonator for vapor-phase speed of sound and measurements of 1,1,1,2,2,3,3-heptafluoro-3-methoxypropane (RE347mcc) and trans-1,3,3,3-tetrafluoropropene [R1234ze(E)]

We describe an apparatus to measure the speed of sound of gas samples at temperatures from (265 to 500) K with pressures up to 10 MPa. The speed of sound was determined from the frequency of the three lowest-order radial resonance modes for the gas in a spherical cavity machined from type 321 stainless steel for corrosion resistance. The spherical resonator was contained in an isothermal copper block that was maintained at the temperature of interest by a multilayer thermostat with vacuum insulation. The dimensions of the spherical cavity were characterized as a function of temperature and pressure though calibration measurements with high-purity argon. The performance of the apparatus was demonstrated with measurements of high-purity methane and ethane. Measurements of the sound speed of 1,1,1,2,2,3,3-heptafluoro-3-methoxypropane (RE347mcc) are reported at temperatures from (325 to 500) K with pressures up to 1.6 MPa. Measurements on trans-1,3,3,3-tetrafluoropropene (R1234ze(E)) are reported at temperatures from (280 to 420) K with pressures up to 2.8 MPa. The average relative combined expanded uncertainties of the measured sound speed for RE347mcc and R1234ze(E) are (0.029 and 0.041)%, respectively.     

Synthesis and crystal structure of a solvate of arsenic 4,6-dimethyl-8-quinolinethiolate

A crystallosolvate of arsenic 4,6-dimethyl-8-quinolinethiolate, As[4,6-Me₂C₉H₄NS]₃⋅CHCl₃ has been synthesized. The molecular and crystalline structures of the compound have been determined by X-ray structural analysis. The influence of the composition and structure of the ligand on the geometry of the coordination environment of the central arsenic atom in the investigated crystal structures of intracomplex compounds of 8-quinolinethiols is discussed.     

The preparation of a novel 3-oxo-cyclopenten-2-phosphonate derivative,useful intermediate for 2-alkyl-substituted cyclopentenones synthesis.

Starting from a phosphonyl-furylcarbinol derivative, diethyl(l-methyl-3-oxo-cyclopenten-2-yl)phosphonate, first example of oxocyclopentenyl-phosphonate and useful intermediate for the synthesis of 2-alkylsubstituted cyclopentenones, has been prepared.     

樟脑酮亚胺衍生物的合成及立体结构研究

从d-樟脑出发, 经六步反应合成了一种新的樟脑酮亚胺衍生物──7,7-二甲基-双环[2,2,1]=2-(苄)亚胺-10-(N-邻羟基苯基酰胺(2)。化合物的晶体的晶胞参数a=8.6904(9), b=10.9400(16), c=20.8583(33)埃; Z=4; V=1983.06(0.45)埃^3; 属P212121空间群, 用反常散射法测定分子的绝对构型为1S, 4R, 并讨论了该化合物作为不对称反应合成子的立体选择的影响因素。     

The enantio- and diastereoselective synthesis of the first phospho-statine derivative

The title compound was synthesized by the diastereoselective addition of the lithium or sodium anion of dimethyl methylphosphonate to $\text{N}$-trityl-L-phenylalaninal.