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41.
A. A. El-Barbary A. Z. Abou-El-Ezz A. A. Abdel-Kader Mai El-Daly Claus Nielsen 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1497-1508
Some novel [1,2,4]triazolo[3,4-b][1,3,4]thiadiazolylisoindole-1,3-dione 2a–c were prepared by heating 4-amino-5-aryl-1,2,4-triazole-3-thiones 1a–c with different (1,3-dioxo-1,3-dihydro-isoindol-2-yl) carboxylic acids in POCl3. Compounds 2a, b were hydrolyzed using HCl to yield [1,2,4]triazolo[3,4-b][1,3,4]thiadiazolyl-alkylamines 3a, b. Coupling 1a, c with 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide (ABG) afforded the corresponding S-glucosides 4a, b, which on oxidation with KMnO4 gave the corresponding sulfone 5. Treatment 1b, c with diphenyl diazomethane afforded benzhydrylsulfanyltriazolylamines 7a, b. 1,8-Bis-(4-chloro-phenyl)-bis[1,2,4]triazolo[3,4-c-,4′,3′-e][1,2,4,5]dithiadiazine 8 was formed by oxidation of 1b with lead tetracetate. Compound 1c reacted with morpholine in the presence of KI and I2 to give the triazolodisulfide 9 . 相似文献
42.
H.-J. Mai S. Wocadlo H.-C. Kang W. Massa K. Dehnicke C. Maichle-Mssmer J. Strhle D. Fenske 《无机化学与普通化学杂志》1995,621(5):705-712
Phosphanimine and Phosphoraneiminato Complexes of Iron. The Crystal Structures of [FeCl3(Me3SiNPEt3)], [FeCl2(Me3SiNPEt3)]2, [FeCl2(NPEt3)]2, and [Fe(O2C? CH3)2(NPEt3)]2 The phosphanimine complexes [FeCl3(Me3SiNPEt3)] (red-orange) and [FeCl2(Me3SiNPEt3)]2 (colourless) have been prepared by reactions of Me3SiNPEt3 with FeCl3 and FeCl2, respectively, in CH2Cl2 suspensions. Thermal decomposition of these donor-acceptor complexes in boiling toluene leads to the phosphoraneiminato complex [FeCl2(NPEt3)]2 (black), whereas [Fe(O2C? CH3)2(NPEt3)]2 (brown) is formed from iron(II) acetate and Me3SiNPEt3 in boiling acetonitrile. The complexes are characterized by IR spectroscopy and by crystal structure determinations. [FeCl3(Me3SiNPEt3)] (1) : Space group P21/c, Z = 8, structure determination with 4 673 unique reflections, R = 0.033. Lattice dimensions at ?15°C: a = 1 607.8, b = 1 602.0, c = 1 417.2 pm, β = 106.56°. 1 forms monomeric molecules with tetrahedrally coordinated iron atoms. Bond lengths in average: Fe? N = 196.9 pm, Fe? Cl = 219.7 pm. [FeCl2(Me3SiNPEt3)]2 (2) : Space group P21/c, Z = 4, structure determination with 4 992 unique reflections, R = 0.048. Lattice dimensions at 20°C: a = 1 457.9, b = 1 685.4, c = 1 507.3 pm, β = 116.74°. 2 forms dimeric molecules, which are associated by chloro bridges. The iron atoms are tetrahedrally coordinated with trans positions of the phosphanimine ligands. Both lengths in average: Fe? N = 202.2 pm, Fe? Clterminal = 224.7 pm, Fe? Cl bridge = 241.0 pm. [FeCl2(NPEt3)]2 (3): Space group P21/n, Z = 2, structure determination with 2763 unique reflections, R = 0.039. Lattice dimensions at ?70°C: a = 799.1, b = 1009.0, c = 1441.9 pm, β = 93.45°. 3 forms centrosymmetric dimeric molecules, in which the tetrahedrally coordinated iron atoms are associated by the nitrogen atoms of the phosphoraneiminato ligands. Bond lengths in average: Fe? N = 191.4 pm, Fe? Cl = 222.7 pm. [Fe(O2C? CH3)2(NPEt3]2 (4): Space group P21/n, Z = 2, structure determination with 3005 observed unique reflections, R = 0.034. Lattice dimensions at -65°C: a = 886.4, b = 1444.6 pm, β = 90.60°. 4 forms centrosymmetric dimeric molecules, in which the octahedrally coordinated iron atoms are associated by the nitrogen atoms of the phosphoraneiminato ligands with bond lengths Fe? N of 191.9 and 195.0 pm. The acetate groups are coordinated in a chelating fashion. 相似文献
43.
Immobilized enzymes were used as column reactors in a high-performance liquid chromatographic system for the specific detection of N-acetyl branched-chain amino acids (AcBCAs) such as N- acetyl- l -valine (AcVal), N- acetyl- l -leucine (AcLeu) and N- acetyl- l -isoleucine (AcIle). Aminoacylase and leucine dehydrogenase were immobilized onto poly(vinyl alcohol) beads. The AcBCAs were separated as three peaks on a Capcell C(1) SG120 column with 0.03M phosphate buffer (pH 8.0). Aminoacylase was capable of hydrolysing the AcBCAs to amino acids, which react with beta-nicotinamide adenine dinucleotide (NAD(+)) in the presence of leucine dehydrogenase. The reduced nicotinamide adenine dinucleotide (NADH) produced was monitored fluorimetrically. The calibration graphs were linear from 4 to 200muM for AcVal and AcLeu, and from 5 to 300muM for AcIle; detection limits for AcVal, AcLeu and AcIle were 2, 2 and 3muM, respectively. The immobilized aminoacylase reactor should be renewed every 5 days owing to a poor stability of aminoacylase. 相似文献
44.
45.
Ismail MM Kamel MM Mohamed LW Faggal SI Galal MA 《Molecules (Basel, Switzerland)》2012,17(6):7217-7231
A series of new thiophene derivatives has been synthesized using the Gewald protocol. The acetylcholinesterase inhibition activity was assayed according to Ellman's method using donepezil as reference. Some of the compounds were found to be more potent inhibitors than the reference. 2-(2-(4-(4-Methoxyphenyl)piperazin-1-yl)acetamido)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxamide (IIId) showed 60% inhibition, compared to only 40% inhibition by donepezil. 相似文献
46.
Binh Khanh Mai Prof. Yongho Kim 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(11):3568-3572
47.
Tarik E. Ali Mohammed A. Assiri Noha M. Hassanin I. S. Yahia Mai S. A. Hussien 《Journal of heterocyclic chemistry》2019,56(5):1684-1686
Novel diethyl (4‐oxo‐3,4‐dihydro‐2H‐chromeno[2,3‐d]pyrimidin‐2‐yl)phosphonate as two enantiomers and diethyl (4‐oxo‐1,5‐dihydro‐4H‐chromeno[2,3‐d]pyrimidin‐5‐yl) phosphonate were obtained in easy procedure via reaction of 2‐imino‐2H‐chromene‐3‐carboxamide, dimethylformamide dimethyl‐acetal, and diethyl phosphite in a simple one pot. Possible reaction mechanisms were proposed. The structures of the obtained products were confirmed by elemental analyses and spectral tools. 相似文献
48.
Masaki Tachibana Motohisa Furusawa Nobutoshi Kiba 《Journal of inclusion phenomena and macrocyclic chemistry》1995,22(4):313-329
Extraction of carbazole in heptane was performed at 25±1°C with an aqueous dimethyl sulfoxide (DMSO) medium containing -cyclodextrin (CD) at consecutive concentrations in the range of 0–10 mM. The fluorescence intensity of carbazole remaining in the heptane phase was measured by synchronous scanning fluorimetry. The apparent formation constant (K
f) for a 1:1 carbazole: CD inclusion complex in water-DMSO medium was determined by using a linear plot of the distribution ratio calculated from the fluorescence intensities vs. the -CD concentration. The values thus obtained ranged from 477 M–1 in a 10% v/v DMSO medium to 12.1 M–1 in a 60% v/v medium. Good linear relationships were observed between logK
f and the DMSO concentration ([DMSO]), and also between logK
f and the logarithm of the distribution coefficient (K
d) for carbazole. The formation constant in 100% water was estimated to be approximately 1.0×103 M–1 on the basis of the logK
f vs. [DMSO] and the logK
f vs. logK
d correlations. 相似文献
49.
Adnan J. Al-Rehaily Mohammad S. Ahmad Jamal Mustafa Mai M. Al-Oqail Wafaa H. Hassan Shabana I. Khan Ikhlas A. Khan 《Journal of Saudi Chemical Society》2013,17(1):67-76
Solanopubamine (3β-amino-5α, 22αH, 25βH-solanidan-23β-ol), a steroidal alkaloid was isolated from the alkaloidal fraction of Solanum schimperianum in significant yield. Its structure was established by IR, positive ESI-MS, 1D and 2D NMR. The presence of -3β-NH2 and -23β-OH groups was achieved through methylation, acetylation or coupling with octadecanoic and undec-11-enoic acids to produce six derivatives (2–7). Their structures were confirmed by spectroscopic analyses. Solanopubamine and semi-synthetic analogs are investigated for their in vitro cytotoxicity against a panel of human cancer cell lines and anti-microbial activity. Solanopubamine showed good antifungal activity only against Candida albicans and C. tenuis with MIC of 12.5 μg/mL. Semi-synthesized compounds (2–7) have failed to show anti-tumor and anti-microbial activities. 相似文献
50.