Simplified Labeling Approach for Synthesizing 3′-Deoxy-3′-[18F]fluorothymidine ([18F]FLT)

[¹⁸F]FLT (3-deoxy-3-[¹⁸F]fluorothymidine) turned out to be a tracer particularly suitable for PET imaging of tumor proliferation because of lacking degradation in vivo. To facilitate clinical studies with [¹⁸F]FLT, we investigated two new easily accessible precursors, 2,3-anhydrothymidine (AThy) and 5-O-(4,4-dimethoxytriphenylmethyl)-2,3-anhydrothymidine (DMTThy), using a common approach for introducing the label with nucleophilic [¹⁸F]fluoride. Radiochemical yields were determined in dependence on substrate concentration, reaction time and temperature. In the case of AThy (10 mg), best FLT yields were 5.3%±1.2 (130 °C, 30 min). Labeling of DMTThy (10 mg) gave 14.3%±3.3 at 160 °C within 10 minutes. Starting with an aqueous solution of 20 GBq [¹⁸F]fluoride the new method allows to produce 1.3 GBq [¹⁸F]FLT within 90 minutes ready for intravenous injection. The new labeling procedures allow [¹⁸F]FLT synthesis without lengthy preparation of the precursor and with high reproducibility mandatory for clinical application.     

F19(γ, n)F18核反应的化学效应

测定氟苯、邻氟甲苯、对氟甲苯及三氟甲苯经F¹⁹(γ,n)F¹⁸核反应后的化学状态,有机保留百分值分别为39,33,39和47;在照射前加入0.2克分子分数苯胺后,保留值分别降到20,24,20和27。固体对氟苯甲酸的保留为15,3M对氟苯甲酸呲啶溶液为零。测定氟、氯、溴和碘四种卤代苯经(γ,n)核反应产生的氟-18、氯-34、溴-78和碘-126的化学状态,保留值分别为39,74,51和>51,母体保留值分别为19,41,36和>41。并用弹性碰撞理论解释有机氟化物的母体保留占总保留的百分比小于氯、溴和碘的相应化合物的原因。用氟苯及其乙醇溶液、对氟甲苯和对氟苯甲酸等化合物体系,比较F¹⁹(γ,n)F¹⁸和F¹⁹(n,2n)F¹⁸核反应的化学效应。结果说明“热”原子的过剩能量对最终的化学状态无显著的贡献。测定氯、溴、碘三种卤代苯的(n,γ)核反应产生的氯-38、溴-80、碘-128的保留值,并与(γ,n)反应产物作相应的对比,结果同样说明无显著的能量效应。测定氟硼酸钠及其水溶液的(γ,n)产物氟-18的化学状态,保留分别为88和0。用芳基氟和氟硼酸钠可制备高比度的无机氟-18离子。浓集系数的数量级分别为10³和10²。     

F+ and F⁻ affinities of simple N(x)F(y) and O(x)F(y) compounds

Atomization energies at 0 K and heats of formation at 0 and 298 K are predicted for the neutral and ionic N(x)F(y) and O(x)F(y) systems using coupled cluster theory with single and double excitations and including a perturbative triples correction (CCSD(T)) method with correlation consistent basis sets extrapolated to the complete basis set (CBS) limit. To achieve near chemical accuracy (±1 kcal/mol), three corrections to the electronic energy were added to the frozen core CCSD(T)/CBS binding energies: corrections for core-valence, scalar relativistic, and first order atomic spin-orbit effects. Vibrational zero point energies were computed at the CCSD(T) level of theory where possible. The calculated heats of formation are in good agreement with the available experimental values, except for FOOF because of the neglect of higher order correlation corrections. The F(+) affinity in the N(x)F(y) series increases from N(2) to N(2)F(4) by 63 kcal/mol, while that in the O(2)F(y) series decreases by 18 kcal/mol from O(2) to O(2)F(2). Neither N(2) nor N(2)F(4) is predicted to bind F(-), and N(2)F(2) is a very weak Lewis acid with an F(-) affinity of about 10 kcal/mol for either the cis or trans isomer. The low F(-) affinities of the nitrogen fluorides explain why, in spite of the fact that many stable nitrogen fluoride cations are known, no nitrogen fluoride anions have been isolated so far. For example, the F(-) affinity of NF is predicted to be only 12.5 kcal/mol which explains the numerous experimental failures to prepare NF(2)(-) salts from the well-known strong acid HNF(2). The F(-) affinity of O(2) is predicted to have a small positive value and increases for O(2)F(2) by 23 kcal/mol, indicating that the O(2)F(3)(-) anion might be marginally stable at subambient temperatures. The calculated adiabatic ionization potentials and electron affinities are in good agreement with experiment considering that many of the experimental values are for vertical processes.     

STRUCTURE OF [W(H)_2(F)(OH_2)(PMe_2)_4]F

<正> Mr = 546.3, orthorhombic, space group Cmc21, a = 14.223(4), b = 12.907(3), c = 12.343(4) A, V = 2265.746 A3, Z = 4, DC = 1.601 Mg.m-3, λ= 0.7106 A, μ(MoK(?)) = 56.86 cm-1, F(OOO) = 1048. Final R = 0.044 for 1937 observed reflections. Cation [W(H)2(F)(OH2)(PMes)4]4 has a mirror symmetry, an equatorial belt of four PMe3 groups and mutually syn fluoride and water Ugands. The mean W-P length is 2.462 (A) and P-C 1.83 (A). From the dimensions of the metal, fluoride and water system ( W(1)-F(1) = 2.08(1), W(1)-0(1) - 2.084(9), F(2)-O(1) = 2.59(2) A and F(2)-W(1)-O(1) - 76.7(4)°) an in-terligand hydrogen bond was assumed. The ligand water molecule also makes an H-bonded contact with the fluoride counter ion.     

Automated synthesis of [18F]FMISO on IBA Synthera®

In cancer cells hypoxia can cause resistance to both radio- and chemo-therapy. Being able to quantify, the degree of hypoxia in the cells is a useful tool in therapy planning. The positron emitting 1-[¹⁸F]fluoro-3-(2-nitro-1H-imidazol-1-yl)propan-2-ol ([¹⁸F]FMISO) is the most extensively used tracer for imaging hypoxia. Automated synthesis of [¹⁸F]FMISO was set up on IBA Synthera^®. The precursor 1-(2′-nitro-1′-imidazolyl)-2-O-tetrahydropyranyl-3-O-p-toluenesulfonyl propanediol (NITTP) was heated at 100 °C for 10 min with [K/K 2.2.2.]⁺[¹⁸F]^? and thereafter hydrolyzed with 0.1 M hydrochloric acid at 90 °C for 2 min. Purification was performed on solid-phase extraction (SPE) cartridges. [¹⁸F]FMISO was obtained in 50 ± 3 % (n = 6) radiochemical yield (decay-corrected) in 35 min synthesis time with radiochemical purity of ≥98 %. The use of disposable Integrated Fluid Processors (IFP?:s) and cartridge purification simplifies the handling and shortens the synthesis time. This is a no frills setup based on all commercially available materials and the synthesis is performed with minor changes from the FDG time-list.     

Mixed Amidohalotantalates [Ta(NMe2)3X3]– (X = F,Cl)

Russian Journal of Coordination Chemistry - The anionic tantalum complex (ItBuH)[Ta(NMe2)3Cl3] (I) is synthesized by the reaction of [Ta(NMe2)3Cl2]2 with N-heterocyclic carbene ItBu and is isolated...     

正电子发射断层显像剂[18F]FET前体药物的合成

以L-酪氨酸为原料,设计并合成了6个正电子发射断层显像剂[18F]FET前体药物,其中5个未见文献报道,其结构经1H NMR,IR,MS和元素分析表征.     

Synthesis of O-(2-[~(18)F]fluoroethyl)-L-tyrosine and its biological evaluation in B16 melanoma-bearing mice as PET tracer for tumor imaging

O-(2-[18F]fluoroethyl) -L-tyrosine([18F]FET) ,a fluorine-18 labeled analogue of tyrosine,has been syn-thesized and biologically evaluated in tumor-bearing mice. The whole synthesis procedure is com-pleted within 50 min. The radiochemical yield is about 40%(no decay corrected) and radiochemical purity more than 97% after simplified solid phase extraction. [18F]FET shows rapid,high uptake and long retention in the tumor as well as low uptake in the brain. The ratios of tumor-to-muscle(T/M) and tumor-to-blood(T/B) of [18F]FET are similar to those of [18F]FDG,but the ratios of tumor-to-brain(T/Br) are 2-3 times higher than that of [18F]FDG. Autoradiography of [18F]FET demonstrates a remarkable accumulation in melanoma with high contrast. It appears to be a probable competitive candidate for melanoma imaging with PET.     

Isomerization [trans-B20H18]2– → [iso-B20H18]2– during silver(I) complexation with triphenylphosphine

The trans–iso isomerization of the dimeric borohydride cluster anion [B₂₀H₁₈]^2– in the course of the silver(I) complexation reaction with triphenylphosphine has been described for the first time. The isomeric complexes [Ag₂(Ph₃P)₆[trans-B₂₀H₁₈]] and [Ag₂(Ph₃P)₆[iso-B₂₀H₁₈]] have been isolated and characterized by physicochemical methods. The structures of the compounds have been determined by X-ray crystallography.     

Synthesis and crystal structure of bis[(18-crown-6)potassium] bis(μ2-bromo)tetrabromodicopper(II)

A new complex bis[(18-crown-6)potassium] bis(μ₂-bromo)tetrabromodicopper(II), [{K(18-crown-6)}₂Cu₂Br₆] (I), is synthesized and studied by X-ray diffraction analysis (space group P2₁/n, a = 9.137 Å, b = 34.860 Å, c = 13.414 Å, β = 99.53°, Z = 4). The structure is solved by a direct method and refined by the fullmatrix least-squares method in the anisotropic approximation to R = 0.083 for 5850 independent reflections (CAD-4 automated diffractometer, λMoK _α radiation). Complex molecule I consists of the central binuclear anion [Cu₂Br₆]^2? and two peripheral cations K(18-crown-6)]⁺ of the host-guest type bound to the [Cu₂Br₆]^2? anion through two and one K-Br coordination bonds. In the [Cu₂Br₆]^2? anion, the coordination polyhedra of two Cu atoms can be described as strongly flattened tetrahedra. In two [K(18-crown-6)]⁺ fragments, the coordination polyhedra of their K⁺ cations (coordination numbers 8 and 7) are distorted hexagonal pyramids with a base of six O atoms of the 18-crown-6 ligand and a bifurcated or ordinary vertex: the Br atoms of the [Cu₂Br₆]^2? anion. Two 18-crown-6 ligands have a standard crown conformation.     

(±)-Pauciflorol F的全合成

首次完成了(±)-pauciflorol F 的全合成, 其中关键步骤为一步完成Heck反应和烯丙羟基的氧化.     

Synthesis and Crystal Structure of Neodymium Complex[Nd (C_(18)H_(20)N_2O_4) (NO_3)_3]

1INTRODUCT1oNMeta1liccomplexesofsomeSchiffbaseshaveantiviraIandfungistaticac-tivies[1-3i.SomeSchiffbasemetalliccomplexeshavecatalyticactivityasenzyme"'.Thisaspectacu1arresearchfield-WehavereportedthesynthesisandcrystalstructureofNd(llI)nitratecomplexwithN,N-disalicyclideneethylenediamineandDMSO(si'HerethetitlecomplexwasobtainedandcharacterizedbyX-raydiffrac-tion'Theligandisdischiffbaseofcondensationfrom2-hydroxyl-3-methoxyben-zoaldehydeandethylenediamine.2EXPERIMENTAL2.1Synthesi…     

CRYSTAL AND MOLECULAR STRUCTURE OF [K(18-CROWN-6)][Bi(SCN)Cl_3]

<正> The crystal and Molecular structure of [K(18-crown-6)](Bi(SCN)Cl3] has been deterained by X-ray diffraction Method. Its crystal is triclinic, space group Pl,with a = 9.233(4), b = 11.661(5), c=11.738(5)A,a= 81.82(4)° ,β=71.47(4)°,γ=75.55(4)°, and Z = 2. The final structural refine-ment converged with unweighted and weighted R factors of 0.051 and 0.047 for 2924 observed reflections. Results of the structure analysis indicate that the K+ ion enters the cavity of the 18-crown-6 to form the complex cation and one Bi(Ⅲ) atom, one SCN ligand and three Cl atoms fora the anion. Each Bi(Ⅲ) atoa is coordinated by four Cl atoas, of which two are shared with other Bi(Ⅲ) atom, one N atom and one S atoa from two SCN ligands respectively shared with a third Bi(Ⅲ) atoa, forming octahedral geometry.     

[Co(H2O)4(NCS)2]·(18-C-6)配合物晶体的成键特性理论研究

[Co(H_2O)_4(NCS)_2]·(18-C-6)是本文作者之一最近合成的新王冠醚配合物晶体。我们用CNDO/2方法计算了该配合物原子簇模型的电荷分布, Mulliken键级,电子态密度(DOS)等,研究其成键特性。结果表明, 该配合物中存在稳定的[Co(H_2O)_4(NCS)_2]·(18-C-6)集团, 配合单元[Co(H_2O)_4(NCS)_2]采取四根强度不同的氢键与(18-C-6)相结合, 并较好地解释了实验结果。     

A MECHANISTIC STUDY OF THE FORMATION OF [Ru6C(CO)16]2− FROM [Ru6(CO)18]2−

Abstract

The kinetics of the transformation of [Ru₆(CO)₁₈]^2? into [Ru₆C(CO)₁₆]^2? in diglyme over the temperature range 130–160°C have been determined. The results are consistent with reversible loss of a carbonyl ligand from [Ru₆(CO)₁₈]^2?, followed by formation of carbon dioxide and reassociation of carbon monoxide to give the observed product. Mass spectral analysis of the evolved carbon dioxide trapped as barium carbonate supports an intramolecular pathway for the disproportionation of carbon monoxide.     

C_(18)键合相吸附剂富集水中痕量苯并[a]芘

１前言苯并［ａ］芘（ＢａＰ）是多环芳烃（ＰＡＨｓ）类致癌性最强的化合物之一，在饮用水中的含量不得超过０．０１μｇ／Ｌ。用固相萃取（ＳＰＥ）技术富集水样中痕量ＰＡＨｓ的系统研究以前已作过报道［１］，本文选择ＢａＰ为单一目标化合物，重点研究了水样离子强度...     

C_(18)键合相吸附剂富集水中痕量苯并[a]芘

 １前言苯并［ａ］芘（ＢａＰ）是多环芳烃（ＰＡＨｓ）类致癌性最强的化合物之一，在饮用水中的含量不得超过０．０１μｇ／Ｌ。用固相萃取（ＳＰＥ）技术富集水样中痕量ＰＡＨｓ的系统研究以前已作过报道［１］，本文选择ＢａＰ为单一目标化合物，重点研究了水样离子强度和水样中ＢａＰ浓度水平对回收率的影响。２实验部分本文采用实验室合成水样，体积为１００ｍＬ。其它实验条件参见文献［１］。３结果与讨论研究表明，以硅胶为基质的Ｃ１８柱键合相是水中ＢａＰ的理想吸附剂，本实验在文献［１］的优化条件下，着重考察了水样离子强度和ＢａＰ浓度...     

Two modifications of bis(μ2-chloro)tetrachlorodicuprate(II) bis[(18-crown-6)potassium]: Synthesis and crystal structure

Two crystal modifications of a novel complex bis(μ₂-chloro)tetrachlorodicuprate(II) bis[(18-crown-6)potassium, [K{(18-crown-6)}₂Cu₂Cl₆] were synthesized and studied by X-ray diffraction. The structures of two monoclinic modifications—Iα (space group P2₁/n, a = 9.053, b = 33.815, c = 13.469 Å, β = 101.29°, Z = 4) and Iβ (space group P2₁/c, a = 10.991, b = 8.187, c = 22.542 Å, β = 98.15°, Z = 2) were solved by the direct method and refined by the full-matrix least-squares method in anisotropic approximation to R = 0.073 (Iα) and 0.068 (Iβ) for 4883 (Iα) and 3525 (Iβ) independent reflections (CAD-4 automated diffractometer, λMoK _α). The molecules of Iα and Iβ consist of the central binuclear complex anion [Cu₂Cl₆]^2? and two peripheral host-guest cationic fragments [K(18-crown-6)]⁺, each linked with the [Cu₂Cl₆]^2? anions through the K-Cl bonds. The molecule of Iα and centrosymmetric Iβ molecule have different structures, since they have different orientation of the [K(18-crown-6)]⁺ fragments relative to the central [Cu₂Cl₆]^2? anion. The coordination polyhedron of the Cu²⁺ cation in the latter anion in Iα and Iβ is intermediate between flattened tetrahedron and square. In the [K(18-crown-6)]⁺ ions of Iα and Iβ, the K⁺ cation has the distorted hexagonal pyramidal coordination polyhedron with six O atoms of the 18-crown-6 ligand in a base and bifurcate vertex at two Cl atoms of the [Cu₂Cl₆]^2? anion. The 18-crown-6 ligands of Iα and Iβ have standard crown conformation.     

过氧多酸盐[NBu4]3[M(O2)W5O18]的合成及表征

过渡金属过氧化合物是一类性能良好的催化剂,在有机合成中得到广泛的应用[1,2].过氧多酸催化过氧化氢氧化有机物的反应,近年来倍受重视[3～5].