Complete Assignment of the 1H and 13C NMR Spectra of Carthamin Potassium Salt Isolated from Carthamus tinctorius L.

Carthamin potassium salt isolated from Carthamus tinctorius L. was purified by an improved traditional Japanese method, without using column chromatography. The 1H and 13C nuclear magnetic resonance (NMR) signals of the pure product were fully assigned using one- and two-dimensional NMR spectroscopy, while the high purity of the potassium salt and deprotonation at the 3′ position of carthamin were confirmed by atomic adsorption spectroscopy and nano-electrospray ionization mass spectrometry.

Complete Assignment of the 1H and 13C NMR Spectra of Carthamin Potassium Salt Isolated from Carthamus Tinctorius L.

Carthamin potassium salt isolated from Carthamus tinctorius L. was purified by an improved traditional Japanese method, without using column chromatography. The 1H and 13C nuclear magnetic resonance (NMR) signals of the pure product were fully assigned using one- and two-dimensional NMR spectroscopy, while the high purity of the potassium salt and deprotonation at the 3’ position of carthamin were confirmed by atomic adsorption spectroscopy and nano-electrospray ionization mass spectrometry.

Hydroxyl-containing bis(sulfonates). Reaction of 1,4-dibromo-2,3-butanedione with water, methanol and sodium sulfite

Sulfonates are well-known substances with a variety of applications, e.g. as surfactants. On the other hand, bis(sulfonates) bearing hydroxyl or keto group(s) in between the sulfonate groups can be used with or without further modification as starting materials for the preparation of new type of molecules capable to form either complexes or in general supramolecular structures. The synthesis of three hydroxyl-bearing bis(sulfonates), 2-hydroxypropane-1,3-bis(sodium sulfonate) 4, DL-2,3-dihydroxybutane-1,4-bis(sodium sulfonate) 8, and sodium 2,3,4-trihydroxy-1-sulfonate 7 (as by-product) via the Strecker sulfonation are described. Interestingly, under similar conditions, sulfonation of 1,4-dibromo-2,3-butanedione 9 was found to be very complicated and no pure product could be isolated, despite previously reported results on sulfonation of α-halogenated ketones in high yields. There are indications that SO3 2 - attacks at the carbonyl carbon of 9 followed by rearrangement and expulsion of SO4 2 - . 1,4-dibromo-2,3-butanedione 9, bearing two keto groups next to methylene groups, can potentially exist as enols or in the case of its solution in hydroxylic solvents in the form of hemiketals or geminal diols. This behavior of 9 when is dissolved in CDCl3, CD3OD and D2O was studied by means of UV-Vis, 1H and 13C NMR and the nature of the adducts formed was elucidated.

Crystal structure and Biological evolution of 5-bromothiophene based 3,4-dihydropyrimidin-2-(1H)-thi(ones)

Herein, Solvent-free synthesis of 5-bromothiophene based 3,4-dihydropyrimidin-2-(1H)-thi(ones) was explored. The main advantages of this study are that pure product comes in hand with easy workup and without using any separation technique, a good amount of yield, and formation of product in crude form. We developed a single crystal of 4c, and we analysed crystal structure by Hirshfeld surfaces analysis. All the synthesised compounds were screened for antifungal and antibacterial assay. Among all synthesised compounds, 4a, 4b and 4j have potent antibacterial activity. While 4f, 4g, 4h and 4i show good antifungal activity among all synthesised compounds. We also carried out ADMET prediction for the 4(a-j), and calculated data show that all the compounds have prominent drug-like nature.

Synthesis and Characterization of the Structure of Diethyl [(4-{(1H-Benzo[d]Imidazol-1-yl)Methyl}-1H-1,2,3-Triazol-1-yl)(Benzamido)Methyl]Phosphonate Using 1D and 2D NMR Experiments

The biheterocyclic derivative of the phosphonic glycine analogue is prepared selectively by reaction between the α-azidoamino diethyl methylphosphonate and the 1-(prop-2-yn-1-yl)-1H-benzo[d]imidazole. The dipolar -1,3 cycloaddition reaction using Click Chemistry was carried out in a solvent water/ethanol mixture in a ratio of 1:1. Copper sulphate pentahydrate and sodium ascorbate are used in the reaction in catalytic amounts. The compound [diethyl [{4-[(1H-benzo[d]imidazol-1-yl)methyl]-1H-1,2,3-triazol-1-yl}(benzamido) methyl] phosphonate was isolated pure as a white powder, after chromatography on a silica gel column (ethyl acetate/hexane acetate: 1/1). The yield of pure product is 90%, after recrystallization in an ether/hexane mixture. The structure of the -1,4 isomer is attributed to the compound obtained by means of 1D and 2D NMR and based on data from the literature concerning the cycloaddition reaction via Click Chemistry. Two-dimensional NMR spectroscopy played a major role. The analysis of the different correlations between adjacent hydrogens and carbons, and also between hydrogens and distant carbons, confirmed the proposed structure.

Simple and Robust Nitroxide-mediated Polymerization with Oxygen Tolerance

Nitroxide-mediated polymerization (NMP) is a typical reversible deactivation radical polymerization (RDRP) with simple components and pure product. Here we presented the first example of NMP with oxygen tolerance, using alkoxyamine...

Zhurkov’s Stress-Driven Fracture as a Driving Force of the Microcrystalline Cellulose Formation

Microcrystalline cellulose (MCC) is a chemically pure product of cellulose mechano-chemical conversion. It is a white powder composed of the short fragments of the plant cells widely used in the modern food industry and pharmaceutics. The acid hydrolysis of the bleached lignin-free cellulose raw is the main and necessary stage of MCC production. For this reason, the acid hydrolysis is generally accepted to be the driving force of the fragmentation of the initial cellulose fibers into MCC particles. However, the low sensibility of the MCC properties to repeating the hydrolysis forces doubting this point of view. The sharp, cleave-looking edges of the MCC particles suggesting the initial cellulose fibers were fractured; hence the hydrolysis made them brittle. Zhurkov showed that mechanical stress decreases the activation energy of the polymer fracture, which correlates with the elevated enthalpy of the MCC thermal destruction compared to the initial cellulose.

Precipitation and Crystallization Used in the Production of Metal Salts for Li-Ion Battery Materials: A Review

Li-ion battery materials have been widely studied over the past decades. The metal salts that serve as starting materials for cathode and production, including Li2CO3, NiSO4, CoSO4 and MnSO4, are mainly produced using hydrometallurgical processes. In hydrometallurgy, aqueous precipitation and crystallization are important unit operations. Precipitation is mainly used in the processes of impurity removal, separation and preliminary production, while controlled crystallization can be very important to produce a pure product that separates well from the liquid solution. Precipitation and crystallization are often considered in the development of sustainable technologies, and there is still room for applying novel techniques. This review focuses on precipitation and crystallization applied to the production of metal salts for Li-ion battery materials. A number of novel and promising precipitation and crystallization methods, including eutectic freeze crystallization, antisolvent crystallization, and homogeneous precipitation are discussed. Finally, the application of precipitation and crystallization techniques in hydrometallurgical recycling processes for Li-ion batteries are reviewed.