Characterisation of the complex mixtures of carboxylic acids (naphthenic acids) occurring in crude oils and in degraded oil sands is environmentally important. Indeed some acids in waters from oil platforms are apparently hormonally active, and the oil sands acids are said to be toxic to a wide range of biota. Previous attempts to identify monocyclic and monoaromatic naphthenic acids have been hampered by the lack of authenticated synthetic reference compounds. Some studies have indicated that acids with ethanoic acid side chains are present in the naphthenic acids mixtures, so in the present study, we synthesised and characterised by mass spectrometry, a range (C 8-14 ) of monoaromatic and monocyclic ethanoic acids. Using 2-D comprehensive gas chromatographymass spectrometry, we then compared the retention times and mass spectra of the synthetic acids with those of a commercial naphthenic acids mixture. Some alicyclic and numerous aromatic acids were successfully identified.
The extraction for three isomers of bisphenol F (BPF) was studied in a hydrophobic ionic liquid/water biphasic extraction system. The influences of some factors, such as ionic liquid structure, phase ratio, temperature, pH value, and NaCl concentration on the extraction of BPF three isomers were investigated, and excellent efficiency with more than 99.0 % extraction efficiency was obtained using 1‐octyl‐3‐methylimidazolium tetrafluoroborate ([Omim][BF4]) as an extractant. The extraction mechanism of the hydrogen bonds interaction between [Omim][BF4] and BPF three isomers were proven by 1H‐NMR spectrum and the density functional theory (DFT). From the 1H‐NMR spectrum, the immediate disappearance of the BPF isomer hydroxyl protons upon addition of [Omim][BF4] was found, which indicated the existence of hydrogen bond interaction between BPF isomer and [Omim][BF4]. Through the computer simulation, the hydrogen bonds strength decreased in the order of 2,2′‐BPF > 2,4′‐BPF > 4,4′‐BPF, which is consistent with the descending order of distribution coefficients obtained through the experiments. These results are promising for the liquid‐liquid extraction and enrichment of phenols in related industrial processes.
In the title compound, C16H14ClN3O2, all bond lengths and angles are normal. The mean plane of the oxadiazoline ring makes dihedral angles of 1.94 (3) and 82.05 (3)° with the substituted pyridine and benzene rings, respectively. No classical hydrogen bonds are evident in the crystal packing.
A series of heterocyclic compounds 3-acetyl-2,5-disubstituted-1,3,4-oxadiazolines (2a-2g) were prepared with hydrazones and acetic anhydride. The products were characterized by 1H-NMR, 13CNMR, IR and elemental analysis. Furthermore, these compounds were tested for their bioactivities of anti-Staphylococcus aureus, HIV-1 RT (Human Immunodeficiency Virus Type 1 Reverse Transcriptase) and proliferative. However, there were no compounds showed promising activities with S. aureus, HIV-1 RT, HT-29 cells and HT-1080 cells.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.