A simple, efficient, and environmentally benign procedure for the synthesis of 2-amino-4H-chromene ring has been achieved by the three-component reaction of an aromatic aldehyde, malononitrile and diverse enolizable C-H activated compound under ultrasound irradiation using sodium carbonate as a catalyst in aqueous media. Sodium carbonate as a natural salt, being available as an inexpensive catalyst combined with ultrasound method promoted this protocol in comparison to other methods and catalysts.
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http://dx.doi.org/10.2174/1386207318666150224112853 | DOI Listing |
Nature
January 2025
Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA.
Evaporation or freezing of water-rich fluids with dilute concentrations of dissolved salts can produce brines, as observed in closed basins on Earth and detected by remote sensing on icy bodies in the outer Solar System. The mineralogical evolution of these brines is well understood in regard to terrestrial environments, but poorly constrained for extraterrestrial systems owing to a lack of direct sampling. Here we report the occurrence of salt minerals in samples of the asteroid (101955) Bennu returned by the OSIRIS-REx mission.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Science Education, Graduate School of Humanities and Social Sciences, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
The thermal dehydration of sodium carbonate monohydrate (SC-MH) exhibits kinetic characteristics that are typical of the thermal decomposition of solids with a reversible nature. One of the characteristics is the physico-geometrical constraints of the reaction due to the heterogeneous reaction feature. Another factor is the considerable impact of the atmospheric and self-generated water vapor on the kinetics.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China. Electronic address:
In this study, water-soluble fraction (WSF), chelator-soluble fraction (CSF), and sodium carbonate-soluble fraction (NSF) were sequentially fractionated from pear pulp, of which physicochemical properties and hypolipidemic activities in vitro were evaluated. They showed distinct monosaccharide composition, surface morphology, nuclear magnetic resonance (NMR), and Fourier transform infrared (FT-IR) spectrums. WSF and NSF were identified as high methyl-esterified pectic polysaccharides with degrees of methyl esterification (DM) of 85.
View Article and Find Full Text PDFMembranes (Basel)
January 2025
Godo Shigen Co., Ltd., 1545-1 Nanaido, Chosei-mura, Chiba 299-4333, Japan.
Iodine, being an important resource, must be recovered and reused. Iodine is not only attracted to the hydrophobic silicone membrane but also easily vaporized. In this study, we explored the use of five types of silicone hollow fiber membrane modules (SFMMs) for separating iodine in the gaseous phase.
View Article and Find Full Text PDFGels
January 2025
Department of Packaging, Yonsei University, Wonju 26493, Republic of Korea.
Sodium carbonate is an abundant, low-cost, and low-hazard raw material widely used as a food additive and CO absorbent in the food industry. However, its application in food packaging is limited because it is used in solid form, either in sachets or as a compounding ingredient in plastics. Solid sodium carbonate requires an external moisture supply for CO absorption, with its performance dependent on moisture availability.
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