Synthesis,structural characterization,and anion interactions of new triazole-linked urea derivative fully substituted cyclotriphosphazene compounds

Three novel fully substituted urea derivative cyclotriphosphazene compounds 5–7 were synthesized by alkyne-azide 1,3-dipolar cycloaddition reaction of propargyl substituted ureas 2–4 with hexaazide substituted cyclotriphosphazene 1 in the presence of Cu(I) catalyst. All compounds were characterized with spectroscopic techniques such as FT-IR, ¹H, ¹³C, and ³¹P nuclear magnetic resonance and mass spectroscopy. Also, the usefulness of compounds 5–7 as anion carriers was investigated by ¹H NMR spectroscopy. For this purpose, ¹H NMR spectra of compounds 5–7 were recorded in the presence of tetrabutylammonium fluoride in DMSO-d₆. It was determined, that the urea protons in the compounds interact with fluoride.     

Structural studies of cyclic ureas: 1. Enthalpies of formation of imidazolidin-2-one and N,N′-trimethyleneurea

A thermophysical and thermochemical study has been carried out for crystalline imidazolidin-2-one and N,N′-trimethyleneurea [tetrahydropyrimidin-2(1H)-one]. The thermophysical study was made by differential scanning calorimetry, d.s.c., in the temperature intervals between T = 268 K and their respective melting temperatures. Several solid–solid transitions have been detected in imidazolidin-2-one. The standard (p^° = 0.1 MPa) molar enthalpies of formation, at T = 298.15 K, for crystalline imidazolidin-2-one and N,N′-trimethyleneurea [tetrahydropyrimidin-2(1H)-one], were determined using static-bomb combustion calorimetry. The standard molar enthalpies of sublimation, at T = 298.15 K, for the two compounds were derived from the variation of their vapour pressures, measured by the Knudsen effusion method, with the temperature. These two thermochemical parameters yielded the standard molar enthalpies of formation of the two cyclic urea compounds studied in the gaseous phase at T = 298.15 K. These values are discussed in terms of molecular structural contributions and interpreted on the bases of the “benzo-condensed effect” and of the ring strain of imidazolidin-2-one.     

Intramolecular Diamination and Alkoxyamination of Alkenes with N-Sulfonyl Ureas With N-Iodosuccinimide

Reaction of N-δ-alkenyl-N'-sulfonyl urea 1 with N-iodosuccinimde (NIS; 2 equiv) and a catalytic amount of AgOTf (20 mol %) at room temperature led to intramolecular alkoxyamination to form bicyclic isourea 2a in 95% isolated yield. In comparison, reaction of 1 with NIS and sodium bicarbonate (1 equiv) at room temperature led to isolation of bicyclic imidazolidin-2-one 2b in 91% yield. These NIS-mediated alkoxyamination and diamination protocols were effective for a range of N-δ-alkenyl-N'-sulfonyl ureas to form the corresponding heterobicyclic compounds in good yield with high chemoselectivity and good to excellent diastereoselectivity.     

Preparation, isolation, and characterization of Nalpha-Fmoc-peptide isocyanates: solution synthesis of oligo-alpha-peptidyl ureas

The N(alpha)-Fmoc-peptide isocyanates 3a-q, 4a-c, and 5a-c were prepared by the Curtius rearrangement of N(alpha)-Fmoc-peptide acid azides in toluene under thermal, microwave, and ultrasonic conditions. All the N(alpha)-Fmoc-oligo-peptide isocyanates made were isolated as stable crystalline solids with 71 to 94% yield and were fully characterized by 1H NMR, 13C NMR, and mass spectroscopy. Their utility for the synthesis of oligo-alpha-peptidyl ureas 7a-f and 8a-c by the divergent coupling approach was demonstrated. The coupling of N(alpha)-Fmoc-dipeptide isocyanates with amino acid ester or with N,O-bis(trimethylsilyl)amino acids resulted in N(alpha)-Fmoc-tripeptidyl urea ester and acids containing one each of peptide bond and urea bond. The divergent approach is extended to the synthesis of tetrapeptidyl ureas by the 2 + 2 strategy using bis-TMS-peptide acid as an amino component. To incorporate urea bonds in adjacent positions, N(alpha)-Fmoc-peptidyl urea isocyanates 9a-d were prepared and employed in the synthesis of three tetrapeptidyl ureas 10a-b and 11 containing one peptide bond and two urea bonds in series from the N-terminal end. The protocol was then employed for the synthesis of five urea analogues 13-15, 18, and 21 of [Leu5]enkephalin containing urea bonds at the 2, 3, 4 positions as well as at the 2, 4 and 2, 3, 4 positions. The analogue 2l was made by the convergent synthesis by the N --> C terminal chain extension. Finally, two urea analogues 22 and 23 of repeat units of bioelasto polymers, namely Val-Pro-Gly-Val-Gly-OH and Pro-Gly-Val-Gly-Val-OH, were synthesized incorporating the urea bond by the concomitant isocyanate generation and urea bond formation under thermal conditions.     

Design,synthesis and evaluate of imidazole,triazine and metastable oxazolone derivatives as chemosensor for detecting metals

In the current work, a novel series of substituted imidazole, triazine and metastable Oxazolone derivatives were synthesized. The performance of 4-arylideneoxazol-5(4H)-one (2a-c) towards amoniuma acetate, hydrazine hydrate, phenyhydrazine and primary amines has been discussed. DFT bases and calculations of HUMO, LUMO were used to predict the ability of binding between synthesized compound and cations. All the synthesized compounds were assessed as chemosensors for detection metals ions. Colorimetric investigation confirmed and showed high-selectivity and specificity of compounds 5b and 5c to detect cobalt ion, and copper ion respectively, so compounds 5b and 5c can be directed as a chemosensor for optical detection of Co²⁺and Cu²⁺ respectively. On the other hand, new organic chemosensor were established by, IR, ¹H NMR, ¹³C NMR ms spectroscopy and elemental analysis.     

Microwave-Assisted Synthesis,and Stereochemical and Biological Aspects of Some Antimony(III) and Bismuth(III) Complexes with Biologically Potent Bidentate Schiff Bases

Tetra- and pentacoordinated antimony and bismuth derivatives have been prepared by the interactions of monophenylantimonydichloride(III), trichlorostibane, and trichlorobismuthane with the sodium salts of 3-(indolin-2-one)hydrazinecarbothioamide (L¹H) and 3-(indolin-2-one)hydrazinecarboxamide (L²H), under microwave irradiation as well as by conventional heating. These compounds were further characterized by analytical and spectroscopic techniques including UV, IR, ¹H NMR, and ¹³C NMR spectra. Newly synthesized complexes with their corresponding ligands were also tested for their antifungal and antibacterial activities.     

N－5－四唑基－N′－芳甲酰基脲的合成及其生物活性

合成了15个新的含四唑的基的芳甲酰基脲类化合物，用IR，^1H NMR和元素分 析证实了它们的结构，并进行了初步的生物活性试验，生测结果证明一些目标化合 物具有优良的植物生长调节活性，其中N－5－四唑基－N′－芳甲酰基脲（2h)和N －5－四唑基－N′－对溴苯基甲酰基脲（2j)具有很好的生长素活性，2h,2j和N－ 5－四唑基－N′－对甲基苯基甲酰基脲（2m）具有优良的细胞分裂素活性。     

Hartree-Fock, Møller-Plesset calculations and dynamic NMR study of 3,3-dimethoxy-1-(imidazolidin-2-ylidene)propan-2-one

The experimental (1)H, (13)C NMR spectra of 3,3-dimethoxy-1-(imidazolidin-2-ylidene)propan-2-one were recorded in CDCl(3) at temperature range 213-323 K. The variable temperature spectra revealed a dynamic NMR effect which is attributed to restricted rotation around the C=C double bond. Fast exchange processes of deuterium atoms between CDCl(3) and 3,3-dimethoxy-1-(imidazolidin-2-ylidene)propan-2-one or fast exchange of proton between nitrogen and oxygen atoms of carbonyl group is also revealed by broadening of N-H (singlet) proton NMR signals. Proton and carbon theoretical chemical shifts of the title molecule were calculated by using RHF and MP2-GIAO levels and different basis sets in gas phase at 298 K. The calculated proton chemical shifts show that the experimental values have no agreement with theoretical values, but for carbon chemical shifts a good agreement achieved by using RHF with 6-31G basis set and MP2/3-21G, 6-31G basis sets. Discrepancies are attributed to either the limitations of calculating program, because the change of the structure while rotation are not considered. The results showed that to select of basis set has more important rule, because RHF-GIAO level calculation with 6-31G basis set in gas phase can excellently reproduce the (13)C NMR spectrum. Moreover, MP2/3-21G, 6-31G calculation has not significant influence on (13)C NMR chemical shifts with respect to RHF-6-31G.     

Synthesis of new 2-aryl-6-styryl-2,3-dihydropyridin-4(1H)-one derivatives from curcuminoids

Series of new 2-aryl-6-styryl-2,3-dihydropyridin-4(1H)-one derivatives were synthesized in acceptable to good yields by treatment of the curcuminoids with aqueous ammonia,the mechanism was proposed.By modification of the primary products,total 13 new compounds were obtained.The structures of all products were elucidated by spectroscopy analysis including HR-MS,~1H NMR and ~(13)C NMR.     

Spectroscopic characterization of the 1-substituted 3,3-diphenyl-4-(2'-hydroxyphenyl)azetidin-2-ones: application of (13)C NMR, (1)H-(13)C COSY NMR and mass spectroscopy

The article deals with spectroscopic characterization of azetidin-2-ones. The presence of substituents like hydroxyl, fluoro, methoxy and benzhydryl, etc., on the azetidin-2-one ring significantly affects the IR absorption and (13)C NMR frequencies of the carbonyl group present in these compounds. The presence of an ester carbonyl group or too many methine protons in the molecule has been observed to limit the scope of IR and (1)H NMR spectroscopy in unambiguous assignment of the structure. The application of (13)C NMR, 2D NMR ((1)H-(13)C COSY) and mass spectroscopy in characterization of complex azetidin-2-ones is discussed. An application of the latter two techniques is described in deciding unequivocally between an azetidin-2-one ring and chroman-2-one ring structure for the product obtained by treatment of the 1-substituted 3,3-diphenyl-4-[2'-(O-diphenylacyl)hydroxyphenyl]-2-azetidinones with ethanolic sodium hydroxide at room temperature.     

Synthesis of Si-containing cyclic ureas

1,3-Bis[(triethoxysilyl)methyl]tetrahydropyrimidin-2-one and 1,3-bis[(dimethoxysilyl)methyl]tetrahydro-pyrimidin-2-one have been synthesized on interacting urea with N,N′-bis(silylmethyl)propylenamines (EtO)³⁻ⁿMe_nSiCH₂NH(CH₂)₃NHCH₂SiMe_n(OEt)_3−n (n = 0, 2). Their interaction with boron trichloride has been studied. The structures of all the compounds synthesized have been demonstrated by multinuclear NMR spectroscopy. Dedicated to the 50^th Anniversary of the Latvian Institute of Organic Synthesis __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 238–244, February, 2007.     

A simple and convenient synthesis of 5-amino-substituted tetrazolo[1,5-a]-1,3,5-triazin-7-one salts

A simple and convenient three-step synthesis of 5-amino-substituted tetrazolo[1,5-a]-1,3,5-triazin-7-one sodium salts based on a fairly simple sequence of nucleophilic substitution of chlorine atoms in cyanuric chloride has been developed. The corresponding tetrabutylammonium salts were synthesized by cation-exchange with tetrabutylammonium chloride. The structures of the products were characterized by IR, ¹H NMR and ¹³C NMR spectroscopy, and by elemental and X-ray analysis.     

Two-step α-ureidoalkylation of ureas with 4,5-dihydroxyimidazolidin-2-ones

Two-step α-ureidoalkylation of ureas with various 4,5-dihydroxyimidazolidin-2-ones gave novel 1,3-dialkyl-4,5-bis(3-alkylureido)-, 1,3-dialkyl-4,5-bis[3-(2-pyrimidyl)ureido]-, or 1,3-dialkyl-4,5-bis(3,3-dialkylureido)imidazolidin-2-ones and ensembles of three imidazolidine rings. The structure of 4,5-bis(2-oxoimidazolidin-1-yl)imidazolidin-2-one was confirmed by X-ray diffraction data. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 140–145, January, 2007.     

Pulsed gradient spin echo (PGSE) diffusion measurements as a tool for the elucidation of a new type of hydrogen-bonded bicapsular aggregate

Compounds formed by linking two tris(ureidobenzyl)amine modules with a hexamethylene tether are described. These compounds self-assemble to form bicapsular aggregates featuring two rings of six hydrogen-bonded ureas. (1)H and (1)H/(1)H ROESY NMR spectroscopy, together with pulsed gradient spin echo (PGSE) NMR diffusion measurements, have been used to characterize the dimers in solution. The results have been compared with energy-minimized structures. The new compounds are kinetically stable on the NMR timescale, and their thermodynamic stabilities are comparable to other capsular aggregates derived from tris(ureidobenzyl)amines.     

Enantioselective total syntheses of slagenins A-C and their antipodes

Full details of the total syntheses of slagenins A-C (1a-c) and their antipodes (2a-c), novel bromopyrrole alkaloids with a unique tetrahydrofuro[2,3-d]imidazolidin-2-one moiety, are described in which their absolute stereochemistry was established. The key step in the syntheses involves the efficient condensation of dihydrofuran-3-one or glyoxal with urea to construct the slagenin bicycle core.     

Reaction of 2- and 3-furylmethanephosphonates with esters

2- and 3-furylmethanephosphonates are acylated with ethyl formate, diethyl oxalate, and ethyl trifluoroacetate in toluene in the presence of sodium foil to afford five phosphorylated derivatives of furylacetic aldehyde, furylpyruvic acid, and 1,1,1-trifluoro-1-(2-furyl)propan-2-one. In a chloroform solution these compounds exist in the equilibrium with their enolic forms. When treated with sodium ethylate they form sodium salts which were isolated and characterized by ¹H, ¹³C, and ³¹P NMR spectroscopy. It was shown that in DMSO solutions sodium salts of formyl and oxalyl derivatives of 2-furylmethanephosphonate exist as mixtures of the carbanion and enolate forms. In the first case the carbanion form is predominant, while in the second one the enolate forms prevail. Sodium salt of formylated 3-furylmetanephosphonate exists only in the carbanion form, while the salt of 3-furylpyruvate is enolate. The alkylation of these salts with iodomethane proceeds at the carbon atom as well as at the oxygen one. First reaction pathway is often preferred.     

Nitrogen-rich salts based on energetic nitroaminodiazido[1,3,5]triazine and guanazine

Highly dense nitrogen-rich ionic compounds are potential high-performance energetic materials for use in military and industrial venues. Guanazinium salts with promising energetic anions and a family of energetic salts based on nitrogen-rich cations and the 6-nitroamino-2,4-diazido[1,3,5]triazine anion (NADAT) were prepared and fully characterized by elemental analysis, IR spectroscopy, (1)H NMR and (13)C NMR spectroscopy, and differential scanning calorimetry (DSC). The crystal structures of neutral NADAT (2) and its biguanidinium salt 5 were determined by single-crystal X-ray diffraction (2: orthorhombic, Pnma; 5: monoclinic, P2(1)). Additionally, the isomerization behavior of 2 in solution was investigated by proton-decoupled (13)C and (15)N NMR spectroscopy. All the new salts exhibit desirable physical properties, such as relatively high densities (1.63-1.78 g cm(-3)) and moderate thermal stabilities (T(d) = 130-196 °C for 3-10 and 209-257 °C for 11-15). Theoretical performance calculations (Gaussian 03 and Cheetah 5.0) gave detonation pressures and velocities for the ionic compounds 3-15 in the range of 21.0-30.3 GPa and 7675-9048 m s(-1), respectively, which makes them competitive energetic materials.     

8-羟基喹啉席夫碱衍生物及其金属配合物的合成及荧光性质研究

设计合成了三种新的8-羟基喹啉席夫碱衍生物4-(8-羟基喹啉-5-亚胺甲基)-7-甲氧基苯并吡喃-2-酮(3a),4-(8-羟基喹啉-5-亚胺甲基)-7-己氧基苯并吡喃-2-酮(3b)和4-(8-羟基喹啉-5-亚胺甲基)-7-十八烷氧基苯并吡喃-2-酮(3c)及其铝、锌配合物,产物结构经1H(13C)NMR,MS,HRMS,IR和元素分析表征,研究了它们的荧光发光性能.     

Decomposition of alkene adducts of thianthrene cation radical in nitrile solvents. Formation of alkyl-2-oxazolines and a new class of four-component products: 5-[(1-alkoxyalkylidene)ammonio]alkylthianthrenium diperchlorates

The monoadducts (4a-d) of thianthrene cation radical perchlorate (1a) and isobutene, 2-methylbutene, 2-methyl-2-butene, and 2-methylpentene decompose spontaneously in acetonitrile (MeCN) solution, with the formation of thianthrene (Th). Decomposition of 4a (1,2-(5,10-thianthreniumdiyl)-2-methylpropane diperchlorate) and 4a', the corresponding dihexafluorophosphate, was studied in depth and extensively with (1)H and (13)C NMR spectroscopy. Decomposition of 4a was found to involve the solvent itself as well as water in the solvent, remaining from incomplete drying, and gave, apart from Th, successively, the perchlorate salts of 2,4,4-trimethyl-2-oxazoline (6) and 2-amino-2-methylpropyl acetate (7). These salts, 6-HClO(4) and 7-HClO(4), respectively, were prepared and used in understanding the reactions of 4a as well as the relationships among 6, 7, and 2-(acetylamino)-2-methyl propanol (8) in acidified MeCN solution. Decompositions of 4a-d in MeCN and other nitriles (RCN) containing an added alcohol (R'OH) led to new products, 5-[(1-alkoxyalkylidene)ammonio]alkylthianthrenium diperchlorates (5a-u). These compounds were identified with (1)H and (13)C NMR spectroscopy and, in part, with X-ray crystallography and elemental analysis. The mechanisms of formation of 5-7 are discussed.     

1H, 13C, 15N and 19F NMR study of acetylation products of heterocyclic thiosemicarbazones

Novel 2-acetylamino-4-acetyl-5-aryl(heteryl)-1,3,4-thiadiazolines, 2-acetylamino-5-aryl(heteryl)-1,3,4-thiadiazoles, and some of their salts were prepared and studied by multinuclear 1H, 13C, 15N, 19F and 2D NMR spectroscopy. The acetylation of thiosemicarbazones is accompanied by ring closure to form the corresponding 1,3,4-thiadiazolines and 1,3,4-thiadiazoles. 15N NMR spectroscopy is a unique method for the identification of thiadiazole pyridinium salts.