THE SYNTHESIS OF GLYCOSIDES OF 1-ETHOXYMETHYL-5-FLUOROURACIL

ABSTRACT

Three N-glycosides 3(A–C) of 1-ethoxymethyl-5-fluorouracil were synthesized by the reaction of 2 with α-bromoacetylglucose 1(A–C) under phase transfer catalysis. The compounds 3(A–C) were treated by ammonia to obtain three new compounds 4(A′–C′). Their structures were confirmed by elementary analysis, IR, ¹H NMR.     

Study on Chemiluminescence Assay of Surfactant PEG-400 Using Luminol–Hydrogen Peroxide System

Abstract

Based on the fact that nonionic surfactant polyethylene glycol-400 (PEG-400) catalyzed the chemiluminescence of luminol-H₂O₂ system, a novel and simple chemiluminescence method has been developed for the determination of PEG-400. Under the optimal conditions, the standard curve was Y = 198835X–2091.8, where the correlation coefficient (R) was 0.9999. The detection limit was 4 × 10^?5 g·ml^?1 PEG-400 and the linear range was 1.0 × 10^?4–4.0 × 10^?2g·ml^?1. The relative standard deviation was 3.2% at 2.0 × 10^?3 g·ml^?1 PEG-400 (n = 7). This method has been applied to the determination of PEG-400 in cosmetic samples with satisfactory results. Furthermore, the dynamics characteristic curve of PEG-400 in luminol-H₂O₂ system was compared to typical metallic ion and other surfactants. Moreover, the mechanism of the luminol-H₂O₂-PEG-400 chemiluminescence system was studied, assisted by fluorescence spectra and UV spectra.     

VIBRATIONAL SPECTRA AND STRUCTURE OF ALKOXY AND CHLOROALKOXY DERIVATIVES OF ANTIMONY(V)

Abstract

Vibrational spectra of (CH₃O) _n SbCl_5–n . n = 1: 1; n = 2: 2: n = 3: 3: n = 4: 4; n = 5: 5; have been recorded. According to ir and Raman data 1–5 are centrosymmetrical bridged dimers. The Raman spectra of 3–5 exhibit v(Sb–O) doublets of terminal CH₃O at 530–541 and 550–570 cm^?1; vibrations of the 4-membered Sb₂O₂ ring, observed in the 500–517 cm^?1 region of the ir spectra of 1–5, are absent. The v(C–O) bands of bridged and terminal CH₃O are shifted to higher wave numbers (60 and 31 cm^?1, respectively) in the series 1 → 5. The stability of the dimers increases in the series 1 < 2 < 3 < 4 ? 5. At 100–120°C and in CH₃CN solutions dimers of 1–3 dissociate to monomers (v(Sb–O) 537–540 cm^?1, ir data). The monochloride, 4, is partially dissociated in CH₃CN. On solution of the tetrachloride, 1, in benzene a dimer-monomer equilibrium has been observed, with the dimeric form being predominant.     

SYNTHESIS AND REACTVITY OF N-[N-PHOSPHORAMIDO-1H-BENZIMIDAZOL-2-YL] IMIDATES

N-(-1H-Benzimidazol-2-yl) imidates 1a–c react with chlorophosphoramide to give the N-[-1-N,N,N′,N′-tetramethylphosphoramidoyl-1H-benzimidazol-2-yl]-imidates 2a–c or with dichlorophosphoramide to yield the bis[(N-1-benzimidazol-2-yl)-imidate] phosphoramide derivatives 3a–b. The reaction of compounds 2a–c toward primary amines is studied. The obtained amidine derivatives 4a–b were unambiguously characterized by different spectroscopic techniques (IR, ¹H, ¹³C, and ³¹P NMR, and in some cases MS).     

HALOACETYLATED ENOL ETHERS: 16[5] REGIOSPECIFIC SYNTHESIS OF 5-TRICHLOROMETHYL-PYRAZOLES

ABSTRACT

The regiospecific synthesis and isolation of three series of 5-trichloromethyl-pyrazoles 2f–j, 3a–j and 4a–j from the cyclocondensation of 1,1,1-trichloro-4-alkoxy-3-alken-2-ones (1a–f) or trichloroacetyl containing β-diketones (1g–j) with dry hydrazine and phenyl-hydrazine is reported. It was established by ¹H- and ¹³C-NMR spectroscopy that the 5-hydroxy-5-trichloromethyl-4,5-dihydro-1H-pyrazole intermediates 2a–j were formed quantitatively.     

SYNTHESIS OF 2-AROYLAMINO-5-ARYLOXYMETHYL-1,3,4-THIADIAZOLES UNDER LIQUID-LIQUID PHASE TRANSFER CATALYSIS

2-Aroylamino-5-aryloxymethyl-1,3,4-thiadiazoles (I _1–20 ) are synthesized by the condensation of 2-amino-5-aryloxymethyl-1,3,4-thiadiazoles with aroyl chlorides in the presence of PEG-400 phase transfer catalyst.     

CHLOROSULPHONATION OF 2-ANILINO-1,4-NAPHTHOQUINONE AND SYNTHESIS OF NEWER SULPHONYL DERIVATIVES

Synthesis of 2-anilino-1,4-napthoquinone-3-sulphonyl chloride (2) was achieved from the reaction of the title compound with chlorosulphonic acid. The interesting derivative 2 was used as a building block for synthesis of the sulphonyl derivatives 3–24. All these sulphonyl derivatives were characterized by the physical and spectral data (IR, Mass, ¹H- and ¹³C NMR spectra).     

Isomeric Transformation Of 4-Aminobiphenyl by U.V. Radiation and its Influence on the Determination by Flow Injection Analysis with Amperometric and Spectrophotometric Detection.

Abstract

Two flow-injection methods for the determination of 4-aminobiphenyl by amperometry (glassy carbon electrode) and spectrophotometry are proposed. A sample volume of 200 or 400 μl containing an analyte concentration of 0.1–1.0 μg ml^?1 or 0.8–24.0 μg ml^?1 for amperometric or spectrophotometric detection, respectively, is injected into a carrier stream containing 0.04 or 0.02 M Britton-Robinson buffer at pH 10.0 or 8.0, respectively.

The throughput thus achieved is 200 (amperometry) and 240 samples/h (spectrophotometry) and the relative standard deviation less than 2.5% and 4.2% respectively.

Both methods were applied to the determination of 4-aminobiphenyl in commercially available, legally permitted food colouring additive.     

Expeditious one-pot multicomponent microwave-assisted green synthesis of substituted 2-phenyl Quinoxaline and 7-bromo-3-(4-ethylphenyl) pyrido[2,3-b]pyrazine in water–PEG and water–ethanol

An eco-friendly, expeditious one-pot multicomponent synthesis of substituted 2-phenyl quinoxaline and 7-bromo-3-(4-ethylphenyl) pyrido[2,3-b]pyrazine 4a–k in water–ethanol from easily available starting materials as acetophenone 1, succinamide 2, aromatic amine 3, in situ-generated α-iodo acetophenone from acetophenone, succinamide and catalyzed by silver iodide in combination with green solvent polyethylene glycol-400 and water (2:1) under microwave irradiation. The newly developed protocol with excellent yield of products in very short time of reaction by avoiding the use of lacrimatic α-chloro and α-bromocarbonyl compounds, volatile, toxic organic hazardous solvents, and reagents is the advantage of this research work. The final products were confirmed by their characterization data such as FTIR, ¹H NMR, ¹³C NMR, Mass, HRMS and were compared with its reported method.     

Rapid Spectrophotometric Assay of Cephradine and its Dosage Forms

Abstract

A new spectrophotometric method to determine cephradine based on its reaction with acetylacetone-formaldehyde reagent (pH 4.3) is proposed. The yellow chromophore shows an absorption maxima at 400 nm, having a molar absorptivity coefficient of 2.59. 10³ L mol^?1 cm^?1. Optimization of the reaction conditions has been investigated. Obediance to Beer's law (0–110 mog per ml) permitted the assay of cephradine in its dosage forms. The method has been compared with the official method and found to be simple, artwrate (t-test) and reproducible (F-test).     

NOTE: STRUCTURE OF A COPPER(II) COMPLEX WITH THE MACROCYCLIC LIGAND HEXACYCLEN

Abstract

The saturated macrocyclic ligand 1,4,7,10,13,16-hexaazaoctadecane (hexacyclen, I) exhibits excellent coordination ability^1–5 and extraction properties^6.7 towards different metal ions. Due to the remarkable flexibility of the ligand complexes with different structures are formed.^1–5     

SYNTHESIS AND NMR CHARACTERIZATION OF P-VINYL SUBSTITUTED PHOSPHAZENE PRECURSORS1

Abstract

The reactions of either PhPCl₂ or PCl₃ with (Me₃Si)₂NLi followed by H₂C[dbnd]CHMgBr were used to prepare the new P-vinyl substituted [bis(trimethylsilyl)amino]phosphines, (Me₃Si)₂NP(R)CH[dbnd]CH₂ [1: R=Ph, 2: CH[dbnd]CH₂, 3: R=Me, and 4: R=N(SiMe₃)₂]. Oxidative bromination of phosphines 3–1 afforded the P-bromo-P-vinyl-N-(trimethylsilyl)phosphoranimines, Me₃SiN[dbnd]P(CH[dbnd]CH₂)(R)Br [5: R=Ph, 6: R=CH[dbnd]CH₂, 7: R=Me], which, upon treatment with CF₃CH₂OH/Et₃N, were subsequently converted to the P-trifluoroethoxy derivatives, Me₃SiN[dbnd]P(CH[dbnd]CH₂)(R)OCH₂CF₃ [8: R=Ph, 9: R=CH[dbnd]CH₂, 10: R=Me]. Compounds 1–10, which are of interest as potential precursors to P-vinyl substituted poly(phosphazenes), were fully characterized by elemental analyses (except for the thermally unstable P-Br derivatives 5–7) and NMR spectroscopy (¹H, ¹³C, and ³¹P) including complete analysis of the vinylic proton splitting patterns via HOM2DJ experiments.     

CHEMO-ENZYMATIC SYNTHESIS AND CHARACTERIZATION OF NOVEL FUNCTIONALIZED AMPHIPHILIC POLYMERS

ABSTRACT

The condensation copolymerization of Dimethyl 5-hydroxyisophthalate (1) with Polyethylene glycols (PEGs) (2a–2d) of varying molecular weights, catalyzed by Novozyme-435 (immobilized Candida antarctica lipase B) in bulk is reported. The structures of the resulting polymers, Poly[(poly(oxyethylene)-oxy-5-hydroxyisophthaloyl] (3a–3c) were characterized by ¹H (1D and 2D) and ¹³C-NMR spectroscopic experiments. Further, these polymers have been derivatized by attaching decanyl and 12-hydroxydodecanyl chains to the phenolic hydroxyl group. The resulting amphiphilic polymeric systems were characterized by detailed spectroscopic analysis. Light Scattering Photometry as well as Gel Per meation Chromatography were used to evaluate the particle size and molecular weights of the polymers. In principle, the method developed is flexible so that it can be used to generate a wide array of functionalized amphiphilic polymers. In the absence of biocatalytic transformation, such structural control would be extremely difficult or currently impossible to obtain.     

Pyrocatechol-1-Aldehyde 2-Benzothiazolylhydrazone As Reagent for the Spectrofluorimetric Determination of Nanogram Amounts of Gallium in Urine and Blood Serum

Abstract

A method is developed for the spectrofluorimetric determination of 1–80 ng.ml^?1 of gallium with pyrocatechol-1-aldehyde 2-benzothiazolylhydrazone, in a 50% (v/v) DMSO-Water medium at apparent pH 4.0 (monochloracetic/monochloracetate buffer). Λ_ex = 400nm, Λ_em = 504 nm (corrected). Interferences have been evaluated and the method applied to the determination of gallium in human urine and blood serum samples.     

PRODUCTION OF SOME INORGANIC FORMS OF 35S FOR CHEMICAL SYNTHESIS OF LABELLED ORGANIC COMPOUNDS

Abstract

Some inorganic forms of ³⁵S are used as starting material for some chemical syntheses of labelled organic compounds. The choice depends on the desired characteristics of the labelled compound. Preparation of barium sulphate- ³⁵S, barium sulphide- ³⁵S, ferrous sulphide- ³⁵S, sodium sulphide- ³⁵S and elementary form of ³⁵S, is described. The characteristics of the products, along with determination methods, are given. The products are obtained with high specific activities of: 5–15 Ci/g S barium sulphate-³⁵S; 1–5 Ci/g S barium sulphide- ³⁵S; 100–500 mCi/g S ferrous sulphide-³⁵S; 1–5 Ci/g sodium sulphide-³⁵S and 100–500 mCi/g S elementary ³⁵S.     

SYNTHESIS AND NMR SPECTROSCOPIC INVESTIGATION OF PHENYLPHOSPHORYL DERIVATIVES

Abstract

The syntheses of 16 phenyl- (1 and 3) and phenylthiophosphoryl (2) derivatives are described. The ¹³C and ¹⁷O NMR data sensitively reflect electron density changes in the phosphoryl substituents caused by p^π–d^π back-donation from X/Y to P. Taft constants σ₁ and σ_R ⁰ were derived for 16 phosphoryl substituents.     

PHOTOOXIDATION OF 8-METHOXYPSORALEN WITH SINGLET OXYGEN*

Abstract— The in vitro photooxidation of 8-methoxypsoralen (8-MOP) with singlet oxygen is studied. Irradiation of 8-MOP(295–400 or320–400 nm) in the presence of oxygen for 72 h results in the formation of a product (1.4%) which is identified as 6-formyl-7-hydroxy-8-methoxycoumarin by aid of IR, NMR, MS and co-chromatography with an authentic sample. A study of this reaction in the presence of l,4-diazobicyclo(2,2,2)octane, a singlet oxygen scavenger, indicates the involvement of ¹O₂ in the formation of this compound. In addition to this, formation of a novel dimer of 8-MOP is reported.     

EFFECT OF COORDINATED BASE ON MAGNETIC BEHAVIOR OF COPPER(II) CARBOXYLATES WITH FATTY ACID CHAINS (AN ESR STUDY)

Abstract

The ESR spectra of a series of copper(II) alkanoates with the empirical formula Cu₂ X ₄ (X = heptanoate, octanoate, nonanoate, decanoate, dodecanoate), and their pyridine adducts have been measured over the temperature range 300K to 100K. The spectra of nonadduct copper(II) alkanoates exhibit extreme temperature dependent behavior; the room temperature spectra show a single broad line centered on g ≈ 2.1, however as the temperature is lowered triplet state features appear. The corresponding pyridine adducts give typical triplet state spectra at all temperatures. This temperature behavior can be interpreted in terms of interdimer interactions in copper(II) alkanoates having the polymeric structure. The observed resonance lines are used to calculate the zero-field splitting parameters D and E. The spin Hamiltonian and zero-field splitting parameters are used to estimate the exchange parameter J. The values of /2J/ for the compounds investigated are in the range of 300–400cm^?1 and suggest that the copper(II) ions are strongly antiferromagnetically coupled.     

PEG-400 mediated an efficient eco-friendly synthesis of new isoxazolyl pyrido[2,3-d]pyrimidines and their anti-inflammatory and analgesic activity

Abstract

Polyethylene glycol-400 (PEG-400) has been developed as an efficient and eco-friendly reaction medium for the synthesis of new isoxazolyl pyrido[2,3-d]pyrimidine derivatives 11 from isoxazolyl cyanoacetamide synthon 7. Compound 7 was employed with various aromatic aldehydes 8 and malononitrile 9 in the presence of triethylamine (Et₃N) to afford the corresponding (E)-6-amino-1-(3-methyl-5-styrylisoxazol-4-yl)-2-oxo-4-phenyl-1,2-dihydro- pyridine-3,5-dicarbonitrile 10 at room temperature by using PEG-400 as a solvent medium as well as catalyst. The intermediate 10 on treatment with thiourea in the presence of PEG-400 at 90?°C to give the target compounds isoxazolyl pyrido[2,3-d]pyrimidines 11 in good to excellent yields. The newly synthesized compounds 10 and 11 were characterized by IR, ¹H NMR, ¹³C NMR, and HRMS analysis. The target compounds 11a-x was screened for their anti-inflammatory and analgesic activities. Among the tested compounds, the compounds 11s, 11t, 11u, 11v, 11w, and 11x showed significant anti-inflammatory and potent analgesic activities as that of reference drugs. The advantages of this protocol are operational simplicity, catalyst free, environmental safety, wide substrate scope, good yields, and PEG-400 can be recovered and reused. Most significant of all, this protocol is green.     

An Examination of the Coordination Chemistry of L2Pt(1,2-DITHIOLENES) Using Atmospheric Pressure Chemical Ionization Mass Spectrometry

Abstract

Atmospheric pressure chemical ionization mass spectrometry (APCI–MS) has been utilized in the characterization of two series of platinum dithiolene complexes, (COD)Pt(dt) 1, (COD)–Pt(edt) 2, (COD)Pt(dmid) 3, (COD)Pt(mnt) 4, (COD)Pt(eddo) 5, (COD)Pt(dddt) 6 and (Ph₃P)₂Pt(dt) 7, (Ph₃P)₂Pt(edt) 8, (Ph₃P)₂Pt(dmid) 9, (Ph₃P)₂Pt(dmit) 10, (Ph₃P)₂Pt(mnt) 11 (where COD = 1,5–cyclooctadiene, dt = ethane–1,2–dithiolate, edt = ethylene–1,2–dithiolate, dmid = 1,3–dithiole–2–oxo–4,5–dithiolate, dmit = 1,3–dithiole–2–thione–4,5–dithiolate, mnt = maleonitrile–1,2–dithiolate, eddo = 4–(ethylene–1′,2′–dithiolate)–1,3-dithiole–2–one, and dddt = 5,6–dihydro–1,4–dithiin–2,3–dithiolate). The series that contains triphenylphosphine is labile toward the loss of HPPh₃ ⁺. In addition, an orthometallated species involving the platinum and triphenylphosphine is identified. A dimer is identified for 2, which is shown to be a product of the experiment and not present in the parent material. In addition, a 1:1 adduct with NH₄ ⁺ is identified for 4 and 11 where the NH₄ ⁺ originates from the acid hydrolysis of acetonitrile. Finally, a highly unique ion, Pt⁺, a bare platinum ion, is observed in all COD complexes indicating that a radical mechanism must accompany the decomposition of the COD complexes during the fragmentation process.