Design and Synthesis of Novel Aryloxyalkyl-arylpiperazine Derivatives as αlA-Adrenoceptor Antagonists

A series of 1-[2-(substituted phenoxy)ethyl]-4-(2-methoxyphenyl)-piperazine derivatives have been synthesized. The radioligand receptor binding assay indicated that most of them bind with α1-adrenoceptor specifically, and one of the compound possessed subtype A selectivity.     

Synthesis and Characterization of α-Hexadecyl-DOTA and its Gd（Ⅲ） Chelate

Synthesis and characterization of the ligand, 10-(α-hexadecylcarboxymethyl)- 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (H4L), and its Gd(Ⅲ) chelate are described. Protonation constants for H4L ( lg Ki^H = 10.52, 9.45,4.74, 4.10) and the stability constant for GdL^-(lg KGdL^-=24.50) were determined by potentiometric titrations.The results obtained show that the ligand still maintains the strong chelating properties of the parent DOTA(1,4,7,10-tetraazacyclododecane-N,N‘,N“N′“-tetraacetic acid) after introduction of a linear chain hexadecyl group at the acetic side chain of DOTA, and its basicity is not significantly altered.     

Synthesis,Crystal Structure and Antifungal Activity of a New Zn(Ⅱ) Complex Based on 4-(5-(Pyridin-3-yl)-4H-1,2,4-triazol-3-yl) Benzoic Acid

A new complex[Zn(3,4-APT)2(H2 O)4]·8 H2 O(1,3,4-HAPT=4-(5-(pyridin-3-yl)-4 H-1,2,4-triazol-3-yl)benzoic acid)has been prepared and characterized by elemental analysis,X-ray single-crystal diffraction analysis,thermogravimetric analysis and infrared spectrum analysis.Theoretical calculation based on density functional theory(DFT)is also employed to explicate frontier orbitals of 3,4-HAPT.X-ray single-crystal diffraction analysis reveals that 1 belongs to the triclinic system,space group P1 with a=7.5123(3),b=8.6745(3),c=15.2074(6)?,α=78.469(1),β=87.387(1),γ=65.448(1)°,V=882.42(6)?,Z=1,D_c=1.528 g·cm^–3,μ=0.780 mm^–1,M_r=812.09,F(000)=424,the final R=0.0401 and wR=0.1136.Zn(II)ion is coordinated by two N atoms from two 3,4-HAPT as well as four O atoms from four coordinated water molecules,forming a 0D motif with distorted octahedral coordinated geometry.The adjacent 0 D units are linked into a 3 D supramolecular structure through hydrogen bonding interaction.In addition,complex 1 exhibits better antifungal activity against Colletotrichum gloeosporioides Penz than the ligand and metal salt by MIC,MBC tests and Kirby-Bauer disc diffusion method which exhibit potential application in the antifungal fields.     

Synthesis and Characterization of the Tetrazole Analogues of α-Amino Acids

Tetrazoles have found wide applications in coordination chemistry, medicinal chemistry and material science. Especially, when the tetrazole moiety is served as a surrogate for terminal carboxylic acid residues, the peptides have been presented some pharma…     

Synthesis and Structural Characterization of 2,3-Bis（hydroxymethyl）-2,3-dinitro-1,4-butanediol

2,3-Bis(hydroxymethyl)-2,3-dinitro-1,4-butanediol(C6H12N2O8) was synthesized by condensation,cyclization,oxidative dimerization and deketalization of nitromethane with a total yield of 42.4%.The structure of the title compound was characterized by 1H NMR,13C NMR,FT-IR,elementary analysis,and X-ray single-crystal diffraction analysis,which reveals that the title compound crystallizes in triclinic,space group P with a = 0.6324(2),b = 0.6454(3),c = 0.7062(3) nm,α= 111.550(4),β= 95.505(4),γ= 113.395(4)°,V = 0.23595(16) nm3,Z = 1,Mr = 240.18,Dc = 1.690 g·cm-3,μ = 0.159 mm-1,F(000) = 126,R = 0.0304 and wR = 0.0907.     

Synthesis and Characterization of Novel 4-Methyl-3-isoxazolidinone Derivatives

IntroductionSulfonylureas, as inhibitors of acetohydroxyacidsynthase(AHAS), are a class of herbicides that areused for crop protection. They are used for lowconcen-tration ranges(10—100 g of active ingredient/ha) andare advanced herbicides used in agricu…     

Synthesis and Characterization of ABBA Block Copolymer of Glycolide and ε-Caprolactone

A biodegradable ABBA block copolymer was synthesized via the ring-opening co-polymerization of ε-caprolactone(CL, B) and glycolide(A) by means of step polymerization in the presence of ethylene glycol as an initiator and stannous octanoate as a catalyst at 110 ℃ for 48 h. The molecular length of the PCL pre-polymer(BB) could be adjusted by controlling the molar ratio of the ethylene glycol initiator to ε-caprolactone monomer. The structure and the composition of the block copolymer were determined by the weight ratio of the monomer glycolide(A) to PCL pre-polymer(BB). The block copolymers were characterized by 1H NMR, GPC, DSC and X-ray. The results confirm the successful synthesis of an ABBA block copolymer.     

The Preparation of α-Phosphonovinylzirconocenes and their Application in the Stereospecific Synthesis of α-Halo-l-alkenylphosphonates

Hydrozirconation of 1-alkylnylphosphonates gives the organozirconium(Ⅳ) complexes 2 in syn-addition way.Complexs 2 was trapped with NCS,NBS or I2 to afford stereodifined α-halo-1-alkenylphosphonates in moderate to high yields.     

Synthesis and Characterization of 2-Decyl-DTPA and Its Gd(Ⅲ) Chelate

The present paper covers the synthesis and the characterization of ligand 2-decyl-3, 6, 9-tris(carboxymethyl)-3,6,9-triazaundecan-1,11-dioic acid, H5L, and its Gd(Ⅲ) chelate. The protonation constants for H5L(lgKHi=10.90, 8.50, 4.55, 2.92, 2.20) and the stability constant for GdL2- (lgKGdL2-=22.80) were determined by means of potentiometric titration. They are similar to the corresponding values of DTPA and Gd-DTPA, respectively. The results obtained show that the basicity of the ligand and the stability constant of its Gd(Ⅲ) chelate are not obviously altered after the introduction of a linear chain decyl group into the terminal acetic acid residue of DTPA. The Gd(Ⅲ) chelate may be a potential contrast agent with liver-specificity for magnetic resonance imaging(MRI).     

Synthesis, Crystal Structure and Characterization of α-(1-Benzimidazolyl)-hypnone Cobalt(Ⅱ) Complex:[CoCl(C7H5N2CH2COPh)4]Br

The crystal structure of [CoCl(C7H5N2CH2COPh)4]Br has been determined by means of X-ray crystallography. The molecular structure consists of a discrete [CoCl(C7H5N2CH2COPh)4] cation and one Br- anion. In the [CoCl(C7H5N2CH2COPh)4] cation, the coordination geometry of the central Co atom is square-pyramidal with four tertiary N atoms of benzimidazole from four α-(benzimidazol-1-yl)-hypnone ligands in the basal position and one chloride anion in the apical position. In the solid state, [CoCl(C7H5N2CH2COPh)4] and Br- anion possess intermolecular and intramolecular interactions, which stabilize the crystal structure. The characterization of the title compound were also carried out by using elemeutal analysis, FTIR, UV spectrometries and TG-DSC.     

Potassium tert‐Butoxide Catalyzed Synthesis and Characterization of Novel 3‐Aryl‐3‐(phenylthio)‐1‐(thiophen‐3‐yl)propan‐1‐one Derivatives

A series of thiophenyl‐containing 3‐thiophene derivatives ( 4a – 4i ) were prepared via the reaction of chalcone‐analogua compounds ( 3a – 3i ) and thiophenol in the presence of catalytic amount of KOBu‐t in CH₂Cl₂ with moderate to high yields. The mechanistic pathway of the reaction was explained by the Michael‐type addition of thiophenol to chalcone derivatives ( 3a – 3i ).     

Selective α-Bromination of β-Keto Esters in Reusable PEG-400 under Mild and Catalyst-free Conditions

An efficient bromination protocol for the synthesis of α-bromo-β-keto esters has been developed. In PEG-400 （poly（ethylene glycol-400））, a variety of β-keto esters were treated with NBS （N-bromosuccinimide） at room temperature to selectively afford the corresponding α-monobromination products in excellent yields. It is noteworthy that the reaction was conducted under mild, environmentally benign and catalyst-free conditions.     

5-雄烯-3β, 7α, 17β-三醇和5-雄烯-3β, 7β, 17β-三醇的合成

以5-雄烯二醇为原料,用微生物转化的方法合成了两个重要的神经甾体5-雄烯-3β, 7α, 17β-三醇和5-雄烯-3β, 7β, 17β-三醇。所用菌种总枝毛霉为我们自己筛选,并首次应用于5-雄烯-3β, 7α, 17β-三醇和5-雄烯-3β, 7β, 17β-三醇的合成中。     

Synthesis of Conjugated Polyphenylene Dendritic β-Diketones

An efficient synthesis of high generation conjugated polyphenylene dendrimer-based β-diketones was investi- gated using simple synthetic methods. The new dendrimer-based β-diketones were characterized by NMR, MS and elemental analysis. The UV-Vis and fluorescence spectra of these β-diketones in different solvents were investigated The photoluminescent （PL） quantum yield and TG and DSC curves were also investigated. A new intermediate, 1-bromo-3,5-diiodobenzene, was developed to synthesize high generation dendrimers with good yields.     

SmI2－Mediated Addition Reaction of α－Halomethylsulfones to Carbonyl Compounds. A Convenient Synthesis of β－Hydroxysulfones

Due to the chemoselective dehalogenation by SmI2, the addition of a-halomethylsulfones to carbonyl compounds afforded ,β-hydroxysulfones. Those reactions with α-bromomethylsulfones gave the products in moderate to good yields. The SmI2-mediated addition of gem-dihalomethylsulfones to ketones also afforded α-halo-β-hydroxysulfones in moderate yields.     

Synthesis of Halogenated α,β‐Unsaturated γ‐Butyrolactone Derivatives by Triphenylphosphine‐Catalyzed Cyclization of α‐Halogeno Ketones with Dialkyl Acetylenedicarboxylates (=Dialkyl But‐2‐ynedioates)

A Ph₃P‐catalyzed cyclization of α‐halogeno ketones 2 with dialkyl acetylenedicarboxylates (=dialkyl but‐2‐ynedioates) 3 produced halogenated α,β‐unsaturated γ‐butyrolactone derivatives 4 in good yields (Scheme 1, Table). The presence of electron‐withdrawing groups such as halogen atoms at the α‐position of the ketones was necessary in this reaction. Cyclization of α‐chloro ketones resulted in higher yields than that of the corresponding α‐bromo ketones. Dihalogeno ketones similarly afforded the expected γ‐butyrolactone derivatives in high yields.     

胆甾-4α-甲基-8-烯-3β，7α-二醇二乙酸酯的结构与性质研究

Lophenol, cholest-4α-methyl-7-en-3β-ol (1), obtained from Dracaena cochinchinensis (Lour.) S. C. Chen, was structurally modified. It was acetylated to protect 3β-hydroxyl group, and then oxidised by selenium dioxide in acetic acid to give cholest-4a-methyl-8-en-3β, Ta-diol diacetate (3). This compound 3 is unstable in chloroform solution or when heated and easily converted to a diene compound, cholest-4a-methyl-7,14-dien-3β-ol acetate (4). The structures of 3 and 4 were elucidated by means of IR, ^1H NMR, ^13C NMR and MS, and the absolute configuration of 3 was established by X-ray crystallography. The property of 3 was also discussed in this paper. Both 3 and 4 are new compounds and were reported for the first time.     

Facile Preparation of Homoallyl β′，γ′—Unsaturated Amines via 1,2—Addition of α，β—Unsaturated Imines with Allylsamarium Bromide

A series of homoallyl β′，γ′-unsaturated amines were synthe sized via 1,2-addition of α，β-unsaturated imines with allylsamarium bromide in excellent yields under mild and neutral conditions.     

聚合物负载磺酸催化的三组分反应合成1-酰胺烷基-2-萘酚

聚合物负载磺酸，一种环境友好的固体酸催化剂，可以有效地催化2-萘酚、脲或酰胺和醛的三组分“一锅”反应生成1-酰胺烷基-2-萘酚。该方法得率高，操作简单。     

Stereocontrolled Synthesis of (E)-β,γ-Unsaturated Esters via Palladium-Catalyzed Cross-Coupling of (E)-Alkenylboronic Acids with α-Bromoacetic Esters

The cross-coupling reaction of trans-alkenylboronic acids with a-bromoacetic esters was firstly studied. It was found that using Pd(OAc)2 as catalyst, a bulky electron-rich phospine, (2-dicyclohexylphospino-biphenyl) as ligand, the reaction can be readily accomplished to give specific (E)-b,g-unsaturated esters in high yields.