The synthesis and reactions of trisubstituted N-(X-2-benzothiazolyl)formamidines

1987 ◽  
Vol 52 (4) ◽  
pp. 1006-1014 ◽  
Author(s):  
Margita Lácová ◽  
Nguyen Thi Nga

The modified Vilsmeier-Haack reagent ANC(O)H-ClSO2C6H5 (A = (CH3)2, (C2H5)2, (CH2)5, CH2CH2OCH2CH2) reacts with 2-amino-X-benzothiazole in pyridine and ether to give three types of products in high yields depending on the character of substituents A and X. Isolated were: N,N-dialkyl-N'-(X-2-benzothiazolyl)formamidines, N,N'-bis(X-2-benzothiazolyl)formamidines, and N,N-dialkyl-N',N´´-bis(X-2-benzothiazolyl)triaminomethanes. Investigated were the conditions and reaction products of N,N-dialkyl-N',N´´-bis(X-2-benzothiazolyl)triaminomethanes with phenylethanoyl, phenoxyethanoyl, 4-chlorophenoxyethanoyl, and N-phthalimidoethanoyl chlorides either in ether or in pyridine. Mutual transformations of the individual products are described.

2021 ◽  
Vol 22 (11) ◽  
pp. 5639
Author(s):  
Nikolai Huwa ◽  
Oliver H. Weiergräber ◽  
Christian Kirsch ◽  
Ulrich Schaffrath ◽  
Thomas Classen

The monocot chimeric jacalin OsJAC1 from Oryza sativa consists of a dirigent and a jacalin-related lectin domain. The corresponding gene is expressed in response to different abiotic and biotic stimuli. However, there is a lack of knowledge about the basic function of the individual domains and their contribution to the physiological role of the entire protein. In this study, we have established a heterologous expression in Escherichia coli with high yields for the full-length protein OsJAC1 as well as its individual domains. Our findings showed that the secondary structure of both domains is dominated by β-strand elements. Under reducing conditions, the native protein displayed clearly visible transition points of thermal unfolding at 59 and 85 °C, which could be attributed to the lectin and the dirigent domain, respectively. Our study identified a single carbohydrate-binding site for each domain with different specificities towards mannose and glucose (jacalin domain), and galactose moieties (dirigent domain), respectively. The recognition of different carbohydrates might explain the ability of OsJAC1 to respond to different abiotic and biotic factors. This is the first report of specific carbohydrate-binding activity of a DIR domain, shedding new light on its function in the context of this monocot chimeric jacalin.


Paliva ◽  
2020 ◽  
pp. 87-92
Author(s):  
Jaroslav Aubrecht ◽  
David Kubička

The increasing demand for transportation fuels, especially middle distillates, stimulates the research of new strategies to obtain or synthesize biofuels. The processing of lignocellulosic biomass (for example straw) is a process of great interest, because after its hydrolysis and subsequent dehydration of the resulting sugar monomers, very valuable substances including furfural are obtained. Then, furfural is selectively hydrogenated to 2-methylfuran, sylvan, that is the basic “building block” in the Sylvan process. This manuscript summarizes the knowledge on Sylvan process as a promising way of biofuels synthesis. By sylvan condensing with aldehydes, ketones or even 2-methylfuran itself, it is possible to prepare C13-C16 oxygenates in high yields up to 100 % under mild reaction conditions (30 - 60 °C) over various heterogeneous catalysts. Based on the overview, the heterogeneous catalysts are preferred and the immobilized sulfonic acids are the most active catalysts, however, expensive. The reaction products then may be hydrodeoxygenated commonly over supported noble metal catalysts to provide premium quality C13-C16 hydrocarbons to produce diesel or kerosene. These fractions have great low-temperature properties such as CFPP (-50 °C) or cetane number (70-72). According to the proposed sustainability prediction, this process could be sustainable in the Czech Republic, where 30 % of produced wheat straw could be used for the production of 130 kt advanced biofuels by Sylvan process required by EU directive RED II. Finally, the future approaches have been suggested.


1980 ◽  
Vol 24 ◽  
pp. 265-269 ◽  
Author(s):  
C. A. F. Anderson ◽  
M. E. Zolensky ◽  
D. K. Smith ◽  
W. P. Freeborn ◽  
B. E. Scheetz

AbstractAccurate phase characterization of the alteration products of rad-waste requires the separation and identification of scattered individual grains from among the bulk product. These grains are typically 5 to 100 μm in size. Bulk x-ray powder diffraction will normally not detect these minor phases, and even if the phase can be detected, it often may not be identifiable. The use of the Gandolfi technique with the individual particle not only facilitates the identification, but also allows the assignment of the identification to the specific grain.


2010 ◽  
Vol 10 (4) ◽  
pp. 1969-1988 ◽  
Author(s):  
J. G. Slowik ◽  
A. Vlasenko ◽  
M. McGuire ◽  
G. J. Evans ◽  
J. P. D. Abbatt

Abstract. During the winter component of the SPORT (Seasonal Particle Observations in the Region of Toronto) field campaign, particulate non-refractory chemical composition and concentration of selected volatile organic compounds (VOCs) were measured by an Aerodyne time-of-flight aerosol mass spectrometer (AMS) and a proton transfer reaction-mass spectrometer (PTR-MS), respectively. Sampling was performed in downtown Toronto ~15 m from a major road. The mass spectra from the AMS and PTR-MS were combined into a unified dataset, which was analysed using positive matrix factorization (PMF). The two instruments were given balanced weight in the PMF analysis by the application of a scaling factor to the uncertainties of each instrument. A residual based metric, Δesc, was used to evaluate the instrument relative weight within each solution. The PMF analysis yielded a 6-factor solution that included factors characteristic of regional transport, local traffic emissions, charbroiling and oxidative processing. The unified dataset provides information on emission sources (particle and VOC) and atmospheric processing that cannot be obtained from the datasets of the individual instruments: (1) apportionment of oxygenated VOCs to either direct emission sources or secondary reaction products; (2) improved correlation of oxygenated aerosol factors with photochemical age; and (3) increased detail regarding the composition of oxygenated organic aerosol factors. This analysis represents the first application of PMF to a unified AMS/PTR-MS dataset.


1973 ◽  
Vol 51 (16) ◽  
pp. 2710-2721 ◽  
Author(s):  
E. P. Kündig ◽  
M. Moskovits ◽  
G. A. Ozin

The products of the cocondensation reactions of Pt atoms with N2 at 4.2–10 °K are investigated by matrix isolation infrared and Raman spectroscopy and are shown to be binary dinitrogen complexes of the form Pt(N2)n. Examination of the reaction products in pure 14N2, in 14N2/15N2, in dilute 14N2/Ar, in 14N2/15N2/Ar as well as 14N2/14N/15N/15N2/Ar matrices establishes the stoichiometries of the complexes to be n = 1–3. Structural assignments can be made for the complexes Pt(N2) and Pt(N2)3 which contain end-on bonded dinitrogen and are found to be similar to the corresponding dinitrogen and carbonyl complexes of nickel and palladium. Pt(N2)2 appears to be the exception in this series of complexes, for which side-on bonded dinitrogen is proposed.On the basis of the Cotton–Kraihanzel force field of approximation and the isotope intensity sum rules, isotopic frequencies are computed for the NN stretching modes of the individual complexes and isotopic absorption intensities for Pt(N2)3 and are found to be in close agreement with the observed values. In the case of Pt(N2), the scrambled 14N15N isotope data establish that the dinitrogen ligand is bonded to the Pt atom in an end-on fashion. On the basis of its unusual spectroscopic behavior Pt(N2)2 is proposed to have sideways bonded dinitrogen ligands. Pt(N2)3 in solid α-N2 is found to be slightly distorted from a regular triangular planar molecule but appears to be regular D3h in solid argon. Calculations show that a substitutional site symmetry of C2 for Pt(N2)3 satisfactorily accounts for all the spectral lines observed for the complex in nitrogen. Comparisons are made within the group of binary dinitrogen complexes M(N2)n where n = 1–3 and with the corresponding binary carbonyl complexes M(CO)n. The relationship between the dinitrogen complexes NiN2, PdN2, and PtN2 and nitrogen chemisorbed on those same metals is discussed.


2007 ◽  
Vol 7 (5) ◽  
pp. 1213-1236 ◽  
Author(s):  
R. C. Sullivan ◽  
S. A. Guazzotti ◽  
D. A. Sodeman ◽  
K. A. Prather

Abstract. The accumulation of secondary acids and ammonium on individual mineral dust particles during ACE-Asia has been measured with an online single-particle mass spectrometer, the ATOFMS. Changes in the amounts of sulphate, nitrate, and chloride mixed with dust particles correlate with air masses from different source regions. The uptake of secondary acids depended on the individual dust particle mineralogy; high amounts of nitrate accumulated on calcium-rich dust while high amounts of sulphate accumulated on aluminosilicate-rich dust. Oxidation of S(IV) to S(VI) by iron in the aluminosilicate dust is a possible explanation for this enrichment of sulphate, which has important consequences for the fertilization of remote oceans by soluble iron. This study shows the segregation of sulphate from nitrate and chloride in individual aged dust particles for the first time. A transport and aging timeline provides an explanation for the observed segregation. Our data suggests that sulphate became mixed with the dust first. This implies that the transport pathway is more important than the reaction kinetics in determining which species accumulate on mineral dust. Early in the study, dust particles in volcanically influenced air masses were mixed predominately with sulphate. Dust mixed with chloride then dominated over sulphate and nitrate when a major dust front reached the R. V. Ronald Brown. We hypothesize that the rapid increase in chloride on dust was due to mixing with HCl(g) released from acidified sea salt particles induced by heterogeneous reaction with volcanic SO2(g), prior to the arrival of the dust front. The amount of ammonium mixed with dust correlated strongly with the total amount of secondary acid reaction products in the dust. Submicron dust and ammonium sulphate were internally mixed, contrary to frequent reports that they exist as external mixtures. The size distribution of the mixing state of dust with these secondary species validates previous mechanisms of the atmospheric processing of dust and generally agrees with simulated aerosol chemistry from the STEM-2K3 model. This series of novel results has important implications for improving the treatment of dust in global chemistry models and highlights a number of key processes that merit further investigation through laboratory and field studies.


2020 ◽  
Vol 14 (1) ◽  
pp. 108-121
Author(s):  
Sulochana Sharma ◽  
Kailash Sharma ◽  
Sakshi Pathak ◽  
Mahendra Kumar ◽  
Praveen Kumar Sharma

The study of biodynamic heterosystems has proved to be the most attractive and useful for the development of potential drugs with superior properties and works effectively for the treatment of a variety of diseases, including pandemic ones. Out of the thousand biodynamic heterosystems, the quinazoline heterosystem is one that exhibits wide-ranging biological and pharmacological properties. Synthesis of potential medicinal material is comparatively challenging and needed enough time for clinical trials, testing, permissions for concerned authorities, production and supply. Therefore, researchers usually focused on novel methods incorporated with a high yield of previously approved chemical compounds. This present review article has focused on the synthesis of medicinally important quinazolines and their derivatives, which produce reaction products in less time with high yields, including more attention with eco-friendly green synthesis approaches incorporating multicomponent reactions (MCR), ionic liquids and microwave irradiations.


2018 ◽  
Vol 16 (45) ◽  
pp. 8704-8709 ◽  
Author(s):  
Weihua Li ◽  
Yifeng Wang ◽  
Danqian Xu

A highly enantioselective nucleophilic addition of ketones to versatile imines catalyzed by chiral PTC has been developed, and the process affords the Mannich reaction products with tertiary stereocenters in good to high yields and excellent enantioselectivities. This protocol is effective for gram scale reaction.


2009 ◽  
Vol 27 (Special Issue 1) ◽  
pp. S160-S162
Author(s):  
A. Förster ◽  
C. Börner ◽  
T. Henle

The impact of a diet consisting mainly of “fast food” on the urinary excretion of glycation compounds compared to a usual diet was studied. 9 volunteers followed a well defined diet, starting with one day of individual diet of choice followed by four days of “fast food” embedded in two day periods of MRP-free diet. 24 h-urine samples were collected and analysed for contents of free Amadori product and pyrraline. Urinary excretion of the glycation compounds decreased by 70% to a basic level as a consequence of the MRP-free diet. The following “fast food diet” lead to an increase in excretion of both lysine derivatives, giving evidence for no significant differences between the urinary MRP contents after the individual diets and the “fast food diet”. In summary, our data confirm, that urinary excretion of glycation compounds is affected by the daily diet. Consumption of a “fast food diet” did not lead to an increased urinary excretion of MRPs compared to the diets usually followed by the participants.


1990 ◽  
Vol 45 (12) ◽  
pp. 1709-1714 ◽  
Author(s):  
Heiner Eckert ◽  
Marianne Koller

We want to report on syntheses and test reactions of some ferrocenic compounds which could be used as derivatizing reagents for peptides and proteins in order to detect them electrochemically after an HPLC analysis run. Among the tested compounds we found the 3-ferrocenylpropionic anhydride as the most suitable reagent for this purpose. It is a stable compound which can be prepared with high yields from 3-ferrocenylpropionic acid. Its reaction products with peptides and proteins are highly electroactive which is essential for the sensibility and selectivity of the method.


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