1H-NMR-, 13C-NMR- und IR-Untersuchungen zur Tautomerie von 15N-markiertem 3-Methyl-1-phenyl-Δ2-pyrazolin-5-on

¹H-N. M. R., ¹³C N. M. R., and I. R.-Investigations Concerning Tautomerism of ¹⁵N-Labeled 3-Methyl-1-phenyl-Δ²-pyrazolin-5-one The behaviour of the ¹⁵N-mono and dilabeled compound in dependence on temperature and solvent polarity is described. Chemical shifts, ⁿJ(¹⁵N ¹H), and ⁿJ(¹⁵N ¹³C) coupling constants (n = 1 – 3) have been determined. In the cases of 2, 2, 2-trifluoroethanole and hexafluoroisopropanole the Δ⁴-pyrazolin-3-one is stabilized and detected by ³J(¹⁵N 2 H 4) = 3 Hz, ¹J(¹³C 3 ¹⁵N 2) = 11, 0 Hz and δ(¹³C 5). In HMPT the 5-hydroxypyrazole form predominates and is characterized by ³J(¹⁵N 1 H 4) = 5, 1 Hz and δ (¹³C 5). Coupling constants ³J(¹⁵N 2 H 4) and J(¹³C 3 ¹⁵N 2) could not be observed in this solvent. In accordance with ¹H- and ¹³C-n. m. r.-parameters i. r. measurements in dependence on temperature lead to the conclusion that in DMSO and THF for instance all three tautomers are present and variation of temperature does not change the equilibrium between the tautomers. A good relationship between the content of the CH₂, OH and NH forms and the Donor Numbers (DN) and Acceptor Numbers (AN) by Gutmann has been found.     

A tetrameric dialdehyde formed in the reaction of butyral dehyde and benzylamine: A possible intermediary component for protein cross-linking induced by lipid oxidation

We investigated the reaction of butyraldehyde and benzylamine and analyzed the products to identify the components that produce protein cross-linking in the reaction of butyraldehyde and proteins. When the mixtures of butyraldehyde and benzylamine were incubated at pH 7 and 37°C for 48 hr, many reaction products other than 2-ethyl-2-hexenal and Schiff bases of butyraldehyde and 2-ethyl-2-hexenal were produced. Fluorescent substance(s) were formed only in the presence of dissolved oxygen in the reaction mixture. Three new nonflourescent products—d,e andf—were isolated, and their structures are suggested to be 2,9-dibenzyl-4,6,8-triethyl-7-propyl-2,9-diazabicyclo[3,3,1] nona-3-ene (d), 1-phenyl-2-benzyl- 4,5,7-triethyl-6-propyl-1H,2H,3H,5H,6H,7H,8H-pyrido[1,2-clpyrimidine (e) and 1-phenyl-2-benzyl-4,5,7-triethyl-6-propyl-1H,2H,4aH,5H,6H,7H,8H-pyrido[1,2-c]pyrimidine (f). Formation of these compounds suggested that the protein, cross-linking with butyraldehyde is caused by the tretrameric dialdehyde formed by repeated aldol condensation and Michael reaction of butyraldehyde.     

1H- und 13C-NMR-spektroskopische Messungen und MO-Berechnungen zur π-Elektronenstruktur von p,p′-disubstituierten trans-Stilbenen und substituierten trans-β-Styryl-methyl-sulfonen

¹H and ¹³C n.m.r. Spectroscopical Measurements and HMO-π-Calculations to the π-Electronic Structure of p,p′-Disubstituted trans-Stilbenes and Substituted trans-β-Styryl-methyl-Sulfones The ¹H and ¹³C n.m.r. spectra have been measured for a series of donator-acceptor-disubstituted trans-stilbenes 1 and monosubstituted β-styryl-methyl-sulfones 2 . The ¹³C n.m.r.-signals have been identified by comparison with empirical calculated chemical shifts and quantum chemical determined HMO-π-electrons densities. The influence of substitutents to the experimental chemical shifts are discussed in detail. For 1 and 2 exist linear correlations between chemical shifts and HAMMETT values, and π-electron densities, respectively.     

The characterization of coal tar pitches used in electrode binder manufacture by n.m.r. spectroscopy

Coal tar pitches dissolved in a mixed solvent system comprising S₂Cl₂ and SO₂Cl₂ were analysed by ¹H and ¹³C n.m.r. spectroscopy. The extensive chlorination of the pitch by this solvent unfortunately leads to serious underestimations in aromatic hydrogen concentrations when these solutions are examined by ¹H n.m.r. spectroscopy. However, quantitative data can be obtained using ¹³C n.m.r. spectroscopy where the carbon skeleton is unaffected by the extent of chlorination of the pitch. The ¹H n.m.r. spectra of individual aromatic compounds, similar to those found in coal tars have been recorded. The ¹H n.m.r. spectra confirmed that extensive chlorination of the aromatic nuclei had occurred which results in the non-quantitative estimation of hydrogen concentrations.     

Characterization of the heavy products of coal pyrolysis

In order to obtain information about the production mechanism of large molecules in coal pyrolysis, a subbituminous and two bituminous coals were heated at 500 ° C for 30 s under vacuum. The heavy products were dissolved in tetrahydrofuran (THF) and analysed by ¹H n.m.r. spectroscopy and gel-permeation chromatography in an atmospheric-pressure column. Parallel GPC, ¹H n.m.r. and ¹³C n.m.r. studies were conducted with THF extracts of the same coals. The results are combined with elemental analysis data to obtain structural parameters of the extracts and pyrolysates.     

Nuclear magnetic resonance studies on sequence distributions in vinyl alcohol-vinyl acetate copolymers

The microstructure of vinyl alcohol-vinyl acetate copolymers was studied using both ¹³C n.m.r. and ¹H n.m.r. techniques. The sequence lengths of vinyl acetate units calculated respectively from the compositional dyads, from the methylene absorptions and feom the triple carbonyl absorptions in the ¹³C n.m.r. spectrum were not identical, and moreover the dyad-triad relationship showed a large discrepancy. ¹H and ¹³C n.m.r. spectra of a 5 mol% re-acetylated random sample, containing mainly isolated acetate units, indicate that configurational splitting complicates the assignment of the triple carbonyl absorption, which originally was interpreted as a compositional triad. After correcting for tacticities the results could be brought in line and the C=O resonances proved to be useful in obtaining information on the percentage of isolated vinyl acetate units and the sequence length n^A₂₊ (the average length of vinyl acetate units ≥2).     

Study of structural parameters on some petroleum aromatic fractions by 1H n.m.r./i.r. and 13C, 1H n.m.r. spectroscopy

¹H n.m.r. and i.r. spectroscopy were used to derive molecular parameters of petroleum fractions. Relative amounts are estimated of methylene and methyl groups in substituted alkyl side chains bonded to the aromatic ring system. The resolution of equation combinations leads to estimation of $\text{H}{}_{\mathrm{s}}\text{C}{}_{\mathrm{s}}\text{(=x)}$, which is an important parameter for structural analysis. Several petroleum fractions were characterized in terms of hypothetical average molecular structures using ¹H n.m.r./i.r. procedures, ¹³C coupled proton n.m.r. and Brown—Ladner methods. It is proposed that the ¹H n.m.r./i.r. method gives more precise average molecular parameters than the Brown-Ladner method with the most precise analytical procedure, up to date, being ¹³C coupled proton n.m.r. analysis. The Brown-Ladner method is especially suitable for structural analysis of low aromaticity molecular structures with long straight-chain alkyl substituents.     

An investigation of coal by means of e.s.r., 1H n.m.r., 13C n.m.r. and dynamic nuclear polarization

Sixty coal samples of different rank and origin have been investigated by means of e.s.r., ¹H n.m.r. and ¹³C n.m.r., the last two in combination with dynamic nuclear polarization (DNP). The following parameters have been determined: the number of free radicals, the e.s.r. linewidth, the ¹H Zeeman relaxation rate, the ¹H relaxation rate in the rotating frame, the ¹H DNP enhancement, the ¹³C DNP enhancement, the ¹³C Zeeman relaxation rate and the ¹³C aromaticity, observed via ¹H¹³C cross-polarization (CP), both with and without magic-angle spinning (MAS). The relations between these parameters and coal rank have been investigated. Moreover, with DNP special experiments have been performed which provide information about the localization and the mobility of the unpaired electrons present in these coals. Finally, DNP has been used to investigate various features of the quantitative analysis of coal via ¹³C n.m.r. MAS was found to reduce the measured ¹³C aromaticity, and for three coals it was shown that even without MAS only ≈ 50% of the aromatic ¹³C nuclei are detected by the CP technique.     

Aluminium exchanged Indian clay as an efficient reusable green catalyst for synthesis of 2, 3-dihydroquinazolin-4(1H)-one derivatives

Aluminium exchanged Indian clay (Al³⁺-ExIC) catalyzed synthesis of 2, 3-dihydroquinazolin-4(1H)-one derivatives in good to excellent yields has been reported. The catalyst has been characterized for its physico-chemical properties. Effects of solvent, molar ratio, amount of catalyst and reaction time on the yield of 2-phenyl-2, 3-dihydroquinazolin-4(1H)-one and recyclability of the catalyst have been investigated. Various 2, 3-dihydroquinazolin-4(1H)-one derivatives have been obtained in good to excellent yields.     

A novel synthesis of 1,3 Thiazetidine-2-one and 1,3-Oxazine-2-one Derivatives

In the reactions of acetylthioacetanilides ( 1a–c ) and diacetylthioacetanilides ( 3a–f ) with phosgene 1,3-thiazetidine-2-one ( 2a–c ) and 1,3-oxazine-2-one ( 5a–f ) were obtained respectively. The structures of new compounds were elucidated by elemental analyses, i.r., ¹H-n.m.r., m.s., for 1d–f by ¹⁹F-n.m.r. and for 2a and 5a by ¹³C-n.m.r. spectral data.     

1H- und 13C -NMR-spektroskopische Untersuchungen an substituierten 1, 1-Dioxo-1, 2-thiazinen; Additivität der Substituenteneffekte

¹H- and ¹³C-N.M.R. Spectroscopic Investigations of Substituted 1, 1-Dioxo-1, 2-thiazines; Additivity of the Substituent Effects . The influence of various XCH₂ substituents (X: Cl, Br, I, SCN, SO₂CH₃, SC(NH₂)₂^⊕, Py^⊕) in the 3-, 5- and 3, 5-position of the 1, 1-dioxo-2-phenyl-1, 2-thiazine on the ¹H- and ¹³C-n.m.r. chemical shifts of the ring atoms is described. The substituent effects are additive. The ¹H- and ¹³C-n.m.r. chemical shifts of the 3, 5-substituted 1, 1-dioxo-1, 2-thiazines can be calculated from increments derived from the 3- and 5-substitued compounds.     

1H and 13C n.m.r. spectroscopic methods for the analysis of fossil fuel materials: Some novel approaches

A number of¹H and¹³C n.m.r. methods, apart from conventional procedures which rely on chemical shift classifications alone, can be used to identify chemical or structural characteristics of fossil fuel materials. The information available via multiplet selection in ¹³C n.m.r., two-dimensional J spectroscopy, homonuclear ¹H-¹H correlation spectroscopy, and heteronuclear ¹³C-¹H correlation procedures, is discussed and illustrated.     

取代吲哚-3-甲醛与3-甲基-1-苯基-5-吡唑啉酮的固相缩合反应

在无溶剂、无催化剂、微波辐射条件下,取代吲哚-3-甲醛与3-甲基-1-苯基-5-吡哇啉酮通过固相Knoevenagel缩合反应合成了一系列4-(取代吲哚基-3-次甲基)-3-甲基-1-苯基-5-吡唑啉酮,产物结构经IR,1H NMR确证.最佳反应条件为:n(吲哚-3-甲醛):n(3-甲基-1-苯基-5-吡哇啉酮)＝1....     

Average structures of petroleum pitch fractions by n.m.r. spectroscopy

Ashland A-240 pitch was fractionated by sequential solvent extraction and hypothetical average molecular structures for the whole pitch and its fractions were determined by using ¹H and ¹³C n.m.r. spectroscopy. The average molecules contain condensed aromatic ring systems substituted by short alkyl side chains in both A-240 pitch and the pitch fractions. This result conflicts with Seshadri et al's claim that the Ashland pitch fractions consist of molecules with uncondensed aromatic ring systems linked by aliphatic bridges. It is shown that Seshadri et al's results are probably based on nonquantitative ¹³C n.m.r. data due to the use of a low concentration of paramagnetic relaxation agent.     

Polyesterification and isomerization of maleic anhydride and 1,6-hexane diol as studied by 1H and 13C n.m.r.

The polyesterification and isomerization reaction of 1,6-hexane diol and maleic anydride in a melt without catalyst was studied by ¹³C and ¹H n.m.r. spectroscopy. The structure and concentration of oligoester species during the polyesterification and isomerization were determined depending on the reaction temperature and time. According to the number and configuration of repeating units determined from ¹H n.m.r. spectra kinetics of both reactions were also considered. The degree of isomerization is continuously increasing in the investigated reaction range.     

13C, 2H, 1H n.m.r. and gpc study of structural evolution of a subbituminous coal during treatment with tetralin at 427 °C

Subbituminous Kaiparowitz coal was treated with 1,1-d₂-tetralin or tetralin in sealed tubes at 427 °C and 500 °C for varying periods of time and rates of temperature rise (15 °C/s, 3 °C/s, and 1 °C/s). The time dependence of yields, average molecular weights, molecular-weight distributions and changes in hydroxyl-group content and elemental composition were determined. Deuterium FT n.m.r. was used to monitor the incorporation of deuterium from 1,1-dideuteriotetralin into aliphatic and aromatic structures in the fractionated products. The exchange of ²H with phenol in the presence of the coal was examined to aid in the interpretation of ²H n.m.r. results. ¹³C and ¹H FT n.m.r. and i.r. spectroscopy were used to monitor the fractionated products over time. The ultimate obtainable yields of THF-soluble product were not significantly altered by the shorter temperature-rise times. The highoxygen-containing subbituminous coal undergoes an extremely rapid loss of about 20% of its oxygen by dehydration, and was found to enhance the rate of reduction of acetophenone and the scrambling of deuterium label in tetralin. The growth of benzylic aliphatic hydrogen at the expense of β (ArCH₂C$\text{H}$₂) hydrogen was rapid in the early stages of reaction. In spite of apparently labile aliphatic structures, the preasphaltenes exhibited products above MW 1200 that were stable for more than 2 h at 500 °C.     

Synthesis,Characterization and Anti-Breast Cancer Activity of New 4-Aminoantipyrine-Based Heterocycles

4-Aminoantipyrine was utilized as key intermediate for the synthesis of pyrazolone derivatives bearing biologically active moieties. The newly synthesized compounds were characterized by IR, ¹H- and ¹³C-NMR spectral and microanalytical studies. The compounds were screened as anticancer agents against a human tumor breast cancer cell line MCF7, and the results showed that (Z)-4-((3-amino-5-imino-1-phenyl-1H-pyrazol-4(5H)-ylidene)methylamino)-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 5, 3-(4-bromophenyl) -1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 13, 1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1-Hpyrazol- 4-yl)-3-(4-iodophenyl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 14, 3,3′-(4,4′-sulfonylbis(4,1-phenylene))bis(1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol- 4-yl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile) 16, (Z)-1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-2-hydrazono-4-oxo-3-phenyl-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 17, (Z)-1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-4-oxo-3-phenyl-2-(2-phenylhydrazono)-1,2,3,4-tetrahydro pyrimidine-5-carbonitrile 18, and (Z)-4-(3-amino-6-hydrazono-7-phenyl-6,7-dihydro pyrazolo[3,4-d]pyrimidin-5-yl)-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 19 were the most active compounds with IC₅₀ values ranging from 30.68 to 60.72 μM compared with Doxorubicin as positive control with the IC₅₀ value 71.8 μM.     

Correlation of microautoclave and 1H n.m.r. measurements of coal liquefaction solvent quality

Some 467 coal liquefaction process oils, having nominal boiling points within the range 473–808 K (200–535 °C), were assayed for donor solvent quality in 577 microautoclave tests using three different sets of reaction conditions. Proton distributions were also determined on each sample by ¹H n.m.r. Microautoclave coal conversions and proton distributions, correlated using multiple linear regressions, give similar measurements of solvent quality over a wide range of solvents. Donor solvent quality (as measured by microautoclave coal conversion) increases with increasing hydroaromatic content and with decreasing aromaticity and paraffinicity. As they were designed to do, the different microautoclave tests measure different solvent properties. Above a certain level of solvent quality, microautoclave extractions are insensitive to solvent quality differences. However, ¹H n.m.r. can differentiate between these high quality solvents, and the data can be related to differences in process performance. Advantages of using ¹H n.m.r. for donor solvent quality measurements are discussed.     

Sensibilisierte Photooxidation und 13C-NMR-spektroskopische Untersuchung von 5,6-Dihydrodicyclopentadien-Derivaten

Photooxidation and ¹³C N.M.R. Spectroscopic Investigation of 5,6-Dihydrodieyelo-pentadiene Derivatives The sensitized photooxidation of endo-5,6-dihydrodicyclopentadiene ( 2 ) by singulet oxygen gives via the corresponding hydroperoxide (10) exo-1-hydroxy-5,6-dihydrodieyelopentadiene ( 7a ). Starting from exo-5,6-dihydrodicyclopentadiene ( 6 ) exo-5,6-dihydrodicyelopentadien-1-one ( 12 ) is formed. The ¹³C n.m.r.spectroscopical data of these compounds and of other hydroxy, alkoxy and acyloxy dihydrodieyclopentadiene derivatives are discussed in relation on their structure.     

Partial and complete hydrogenation of poly(1-methyl-1-phenyl-1-sila-cis-pent-3-ene)

Summary Poly(1-methyl-1-phenyl-1-silapentane)(II), andblock copoly(1-methyl-1-phenyl-1-sila-cis-pent-3-ene/1-methyl-1-phenyl-1-silapentane) (block-III) have been prepared by catalytic hydrogenation of poly(1-methyl-1-phenyl-1-sila-cis-pent-3-ene)(I) over 5% palladium on carbon. These polymers have been characterized by¹H,¹³C and²⁹Si NMR as well as IR spectroscopy. Molecular weight distributions have been evaluated by gel permeation chromatography (GPC). Thermal stabilities have been measured by thermogravimetric analysis (TGA). Glass transition temperatures (T_g's) have been determined by differential scanning calorimetry (DSC).