A unique chemical transformation, the base-induced aerobic dimerization of ethyl 4-(2,5-dimethylthiophen-3-yl)-3-ketobutanoate leading to photochromic diarylethene with a 4-hydroxy-4-methylcyclopent-2-ene-1-one as an ethene bridge, is described. This compound is easily subjected to various chemical modifications and can be used as a new diarylethene precursor to produce photoactive compounds with desired properties and functions.
The effect of individual and multicomponent additives of sodium chloride, iron chloride, sodium nitrate and 1-methyl-2-pyrrolidone on the interfacial distribution of thiophene in the systems polyethylene glycol 1500 (PEG-1500) - hexane - water and polyethylene glycol 8000 (PEG-8000) - hexane - water has been studied in this investigation. It was found that in most cases, the introduction of a small amount of individual and joint additives increases the extraction of thiophene from the organic phase to the aqueous.
In the process of using hydrocarbon fractions containing a large amount of nitrogenous compounds, nitrogen oxides are released into the atmospheric air, which have a negative impact on the environment and human health. The traditional cleaning method is treatment with a 25% sulfuric acid solution and subsequent hydrotreating. However, this process becomes disadvantageous due to its inability to achieve ultra-low concentrations of nitrogen-containing compounds (<10 ppm). Extraction using non-toxic and environmentally friendly water-soluble polymers is a promising alternative compared to traditional methods. This work presents the dependence of the interphase distribution of pyridine on the composition of extraction systems based on water-soluble polymers. According to the results of the study, it was found that polyethylene glycol-400, polypropylene glycol-425 and methyl ether of polyethylene glycol-350 exhibit effective extraction properties in relation to pyridine and extract it by 90.95%, 90.33% and 87.82% in one extraction stage, respectively. It was also found that the use of two-phase aqueous systems based on water-soluble polymers in the process of extracting pyridine is promising.
A Convenient Alternative Method for the Synthesis of Dithienylacetylenes. -A convenient two-step approach to the formation of dithienylacetylenes (IV) is developed. The simple procedure as well as the readily available starting materials suggest that this method may find several applications in the preparation of photochromic dithienylethenes with enhanced characteristics. -(LVOV*, A. G.; MILEVSKY, N. A.; SHIRINIAN, V. Z.; KRAYUSHKIN, M. M.; Chem. Heterocycl. Compd. (N. Y., NY, U. S.) 51 (2015) 10, 933-935, http://dx.
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.