Oxidation of 4,7-phenanthroline derivatives

Oxidation of 1,3-diphenyl-4,7-phenanthroline with potassium permanganate in alkaline medium results in transformation of the 4,7-phenanthroline ring system into 1,8-diaazafluorenone. Oxidation of 12-aryl-and 12-aryl-9,9-dimethyl-8,9,10,12-tetrahydro-7H-benzo[b][4,7]phenanthrolin-11-ones (condensation products of 6-arylmethylene-aminoquinolines with 1,3-cyclohexanedione and dimedone) with sodium nitrite in acetic acid leads to 12-aryl-9,10-dihydro-8H-benzo[b][4,7]phenanthrolin-11-ones. 13-Aryl-7,13-dihydro-12H-indeno-[2,1-b][4,7]phenanthrolin-12-ones obtained by reaction of 6-arylmethyleneaminoquinolines with 1,3-indandione are oxidized to 13-aryl-12H-indeno[2,1-b][4,7]phenanthrolin-12-ones on heating in nitrobenzene.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 9, 2004, pp. 1369–1375.Original Russian Text Copyright © 2004 by Gusak, Kozlov, Tereshko.     

4,7-二苯基-1,10-菲啰啉的合成研究

以4-苯基-8-硝基喹啉为起始原料,经还原得到4-苯基-8-氨基喹啉,再以I2/KI为氧化剂,在乙酸和盐酸的存在下,用Skraup法合成了4,7-二苯基-1,10-菲啰啉.化合物结构经IR和1H NMR得到了证实.实验研究得到了最佳的合成条件为:n(3-氯苯丙酮)∶n(4-苯基-8-氨基喹啉)=1.5∶1,I2/KI用量为8%,反应温度120℃,反应时间2.5 h.产品收率可达82%.     

Iron (III) derivatives of 4,7-dihydroxy-1,10-phenanthroline

The chemistry of the iron (III) derivatives of 4,7-dihydroxy-l,10-phenanthroline has been studied in detail. Oxidation of the intensely red tris(4,7-dihydroxy-l,10-phenanthroline) iron (II) ion results in a grey compound, tris(4,7-dihydroxy-l,10-phenanthroline)iron(III), which is stable below pH 10. Above pH 10 the grey compound is partially converted into an amber compound in which the ratio of phenanthroline to iron is 2:1. The amber compound is the conjugate base of a purple 2:1 compound with pK(a) = 9.77. The visible absorption spectra of the three species at various pH values are reported. For 4,7-dihydroxy-1,10-phenanthroline pK(3), as determined by ultraviolet absorptometry, is 12.62 +/- 0.2.     

Synthesis and redistribution reactions of asymmetric σ-arylplatinum(II) complexes containing 4,7-phenanthroline

The mononuclear σ-aryl complexes of the type trans-[Pt(σ-C₆H₄R)(4,7-phen)(PPh₃)₂]OTf (R=4-CO₂Si^tBuPh₂, 4-CONHMe, 3-CO₂Si^tBuPh₂, 3-CONHMe; OTf=trifluoromethanesulfonate) containing a monodentate 4,7-phenanthroline (4,7-phen) ligand were prepared by an oxidative addition reaction of an aryl iodide with Pt(PPh₃)₄ to yield the key iodoplatinum(II) precursors trans-[PtI(σ-C₆H₄R)(PPh₃)₂], followed by halogen metathesis with one equivalent of 4,7-phen. The reaction of trans-[Pt(σ-C₆H₄R)(4,7-phen)(PPh₃)₂]OTf with labile complexes of the type trans-[Pt(OTf)L₂(σ-C₆H₄R′)] (L=PEt₃, R′=H; L=PPh₃, R′=4-CO₂Si^tBuPh₂, 3-CO₂Si^tBuPh₂, 3-CONHMe) afforded the asymmetric dinuclear complexes of the type trans-[Pt(σ-C₆H₄R)L₂(μ-4,7-phen)Pt(σ-C₆H₄R′)L′₂](OTf) ₂ (L=PPh₃, R=4-CO₂Si^tBuPh₂, L′=PEt₃, R′=H; L=L′=PPh₃, R=4-CONHMe, R′=4-CO₂Si^tBuPh₂; R=4-CO₂Si^tBuPh₂, R′=3-CONHMe; R=3-CONHMe, R′=3-CO₂Si^tBuPh₂) in which the 4,7-phen acts as a bridging bidentate ligand. The novel dinuclear species undergo an unusual redistribution reaction that is essentially thermoneutral at 298 K. The exchange process involves facile cleavage of a Pt-N bond and the rapid exchange of trans-[PtL₂(σ-aryl)] units in the equilibrium mixture.     

Pulse radiolysis studies of 4,7-phenanthroline(II)

The one-electron reduction of 4,7-phenanthroline (P) in aqueous solutions at neutral pH has been further studied by pulse radiolysis. The spectral and kinetic properties of the transient formed due to the reaction of 4,7-phenanthroline with hydrated electron were investigated. The transient absorption spectrum obtained 5μs after the pulse exhibits a broad band with a λ_max at 420 nm. The λ_max is 10 nm blue shift compared with the absorption spectrum obtained at pH 2.9 where the reactant was the protonated form. The bimolecular'rate constant of the reaction of 4,7-phenanthroline with hydrated electron was 0etermined to be (2.2±0.1)×10¹⁰ dm³ mol⁻¹ s⁻¹. It was found that the decay of the transient was mainly following a first-order kinetics. The first-order decay rate constant was determined to be (1.25±0.1)×10⁴s⁻¹.     

Reactions of platinum complexes with 4,7-phenanthroline: crystal structures of mono- and binuclear platinum(II) complexes containing 4,7-phenanthroline

The reaction of a mixture of cis and trans-[PtCl₂(SMe₂)₂] with 4,7-phen (4,7-phen = 4,7-phenanthroline) in a molar ratio of 1 : 1 or 2 : 1 resulted in the formation of mono and binuclear complexes trans-[PtCl₂(SMe₂)(4,7-phen)] (1) and trans-[Pt₂Cl₄(SMe₂)₂(μ-4,7-phen)] (2), respectively. The products have been fully characterized by elemental analysis, ¹H, ¹³C{¹H}, HHCOSY, HSQC, HMBC, and DEPT-135 NMR spectroscopy. The crystal structure of 1 reveals that platinum has a slightly distorted square planar geometry. Both chlorides are trans with a deviation from linearity 177.66(3)°, while the N–Pt–S angle is 175.53(6)°. Similarly, the reaction of a mixture of cis and trans-[PtBr₂(SMe₂)₂] with 4,7-phen in a 1 : 1 or 2 : 1 mole ratio afforded the mono or binuclear complexes trans-[PtBr₂(SMe₂)(4,7-phen)] (3) and trans-[Pt₂Br₄(SMe₂)₂(μ-4,7-phen)] (4), respectively. The crystal structure of trans-[Pt₂Br₄(SMe₂)₂(μ-4,7-phen)].C₆H₆ reveals that 4,7-phen bridges between two platinum centers in a slightly distorted square planar arrangement of the platinum. In this structure, both bromides are trans, while the PtBr₂(SMe₂) moieties are syn to each other. NMR data of mono and binuclear complexes of platinum 1–4 show that the binuclear complexes exist in solution as a minor product, while the mononuclear complexes are major products.     

Synthesis and transformations of chloro derivatives of 4,7-dioxobenzo-2,1,3-thladiazole

5-Chloro-4, 7-dioxo- and 5,6-dichloro-4,7-dioxobenzo-2,1,3-thiadiazoles were synthesized, and their reduction to the corresponding dihydroxy derivatives was studied. The bis(semicarbazone) and bis (thiosemicarbazone) of the 5-chloro derivative were obtained, and their antivirus activities were determined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1344–1346, October, 1982.     

Synthesis of pyrrolo[2,3-b]azepine-4,7-dione derivatives

The Dieckmann reaction has been successfully applied for the first time in the synthesis of pvrrolo[2,3-b)]azepines.     

Microdetermination of iron in plant tissue with 4,7-diphenyl-1,10-phenanthroline

A method is described for the wet digestion and colorimetric determination of small amounts of iron in plant tissues. The wet digestion uses a mixture of sulphuric and nitric acids instead of perchloric acid; a volumetric flask is used for weighing, digestion, and dilution. The iron complex with 4,7-diphenyl-1,10-phenanthroline is extracted into hexanol.     

Reaction of 6-aminoquinoline with formaldehyde and cyclic β-diketones. Synthesis of benzo[b]-and indeno[2,1-b][4,7]-phenanthroline derivatives

Three-component condensation of 6-aminoquinoline with formaldehyde and cyclic β-diketones (cyclohexane-1,3-dione and dimedone) gave new partially hydrogenated benzo[b][4,7]phenanthroline derivatives. An analogous reaction with indan-1,3-dione gave indeno[2,1-b][4,7]phenanthroline derivatives. The products were subjected to oxidative dehydrogenation.     

Synthesis of new methyl derivatives of aza-and diazaphenanthrene

By condensation of acetone with 2-naphthylamine and 3-(4-fluorophenyl)-1H-pyrazole-4-, pyridine-3-, quinoline-2-, quinoline-6-carbaldehyde and 4-(2-fluorobenzyloxy)benzaldehyde new 3-aryl(heteryl)-1-methylbenzo[f]quinolines were synthesized. Reactions of acetone with 6-quinolylamine and aromatic aldehydes provided 3-aryl-1-methyl-4,7-phenanthrolines. Intermediate reaction products were isolated: 4-phenyl-or (3-pyridyl)-4-(2-naphthylamino or 6-quinolylamino)butan-2-ones.     

铟(Ⅲ)-向红菲啰啉络合物极谱吸附波的研究

在pH=3.8的磷酸柠檬酸盐缓冲体系中,铟(Ⅲ)-向红菲(口罗)啉络合物在单扫描示波极谱仪上于-0.67 V(vs.SCE)处产生一灵敏的吸附还原波,其二阶导数波灵敏度高,波形好.峰电位Ⅰ~O_P与钢(Ⅲ)浓度在 2.0X10~(-8)~2.0X10~(-6)mol/L范围内呈良好的线性关系,其检测限为8X10~(-9)mol/L铟(Ⅲ).该法用于试剂氧化锌和镀膜玻璃中铟(Ⅲ)的恻定,结果较好.     

Luminescence of 4,7-diphenyl-1,10-phenanthroline forms bound in NAFION membrane

The fixation of 4,7-diphenyl-1,10-phenanthroline on walls of nanosized cavities of a Nafion perfluorosulfonic membrane was realized by two methods: by sorption of molecules on the sulfo groups of the membrane and by coordination attachment to previously grafted La³⁺ and Tb³⁺ cations. The bright luminescence of the molecule forms bound in the membrane is recorded at room temperature in the range of 400–500 nm.     

4,7-二甲氧基-N-乙酰神经氨酸的合成

对4,7-二甲氧基-N-乙酰神经氨酸合成方法进行了研究和改进.以N-乙酰神经氨酸为起始原料,经酯化、缩醛保护、甲基化及水解开环等7个反应,通过四步操作制得目标产物.该路线避免了毒性试剂硫酸二甲酯和危险试剂氢化钠的使用,而且操作简单,条件温和,重复性好.     

Synthesis of quinolyl-substituted 4,7-phenanthrolines

1-(2-Quinolyl)-3-aryl-4,7-phenanthrolines were synthesized by reacting arylidene-6-quinolylamines with 2-acetylqidnoline in n-butanol in the presence of hydrochloric acid. It was found that the formation of the 4,7-phenanthroline ring is preceded by the stage of formation of an intermediate aminoketone, 1-(2-quinolyl)-3-phenyl-3-(6-quinolylamino)propan-1-one. The IR, UV, PMR, and mass spectra of the synthesized compounds are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 796–800, June, 1990.     

Synthesis and reducing power assay of methyl semicarbazone derivatives

In the present study we have designed a new pharmacophore ‘Chalconesemicarbazone’ by pharmacophore hybridization approach of drug design. A series of novel chalconesemicarbazones was synthesized and evaluated for their antioxidant activity by reducing power assay. Most of the compounds were found to be potent antioxidants. Free radicals play an important role in various pathological and xenotoxic effects so antioxidant may have protective role in these pathological conditions. Based on the results of reducing power assay 1-[1-(2,4-dihydroxyphenyl)-3-(2-hydroxyphenyl)allylidene]-4-(4-methylphenyl)semicarbazide (compound 18) and 1-[1-(2,5-dihydroxyphenyl)-3-(6-hydroxyphenyl)allylidene]-4-(4-methylphenyl)semicarbazide (compound 21) were the most active lead compounds. It was found that methoxy and hydroxyl substituted chalconesemicarbazones exhibited potent reducing power and unsubstituted compound showed less reducing potential.     

Iron(II) and nickel(II) mixed-ligand complexes containing 1,10-phenanthroline and 4,7-diphenyl-1,10-phenanthroline

Two types of mixed-ligand complexes, i.e. [M(phen)2 (dip)]2+ and [M(phen)(dip)2]2+ (M = iron(II) and nickel(II); phen = 1,10-phenanthroline and dip = 4,7-diphenyl-1,10-phenanthroline) have been prepared from their related tris-complexes, [M(phen)3]2+ by ligand substitution, and isolated by semi-preparative HPLC. Elemental and chromatographic analyses confirm the purity of the isolated complexes while u.v./vis and i.r. spectra were used to identify and characterize them. 1H-n.m.r. and room temperature Mössbauer spectra of the iron(III) complexes were also measured and the results are discussed. In addition, our preliminary results on hypochromicity in the MLCT band and circular dihroism (CD) emerging in the u.v./vis region upon addition of CT(calf thymus)-DNA to the racemic complexes indicated that the iron(II) mixed-ligand complexes interact with CT-DNA.     

Mono- and di-nuclear oxorhenium(V) complexes of 4,7-diphenyl-1,10-phenanthroline

The reactions of [ReOX₃(AsPh₃)₂] (X = Cl, Br) with 4,7-diphenyl-1,10-phenanthroline (dpphen) have been examined and the complexes [ReO(OMe)X₂(dpphen)] and [Re₂O₃X₄(dpphen)₂]·2/3CH₂Cl₂ (X = Cl, Br) have been obtained. They were characterized by IR, UV–Vis spectroscopy, and single crystal X-ray analysis has been performed for [ReO(OMe)Cl₂(dpphen)] and [Re₂O₃Br₄(dpphen)₂]·2/3CH₂Cl₂. The nature of the frontier orbitals of [ReO(OMe)Cl₂(dpphen)] and [Re₂O₃Br₄(dpphen)₂] and the electronic transitions involved in the absorption spectra have been studied by means of the density functional and time-dependent density functional methods.