- Chemical characterization and physical properties of solvents derived from epoxidized methyl soyate
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Reactions of epoxidized methyl soyate (EMS) with alcohols, carbon dioxide, and acetone yielded liquids with solvent properties that make them more suitable than methyl soyate for dissolving polar substances. The reactions of EMS in the presence of Amberlyst-15 with alcohols, including methanol, ethanol, n-butanol, and 2-methoxyethanol, produced a series of solvents containing ether (-OR) and alcohol (-OH) groups. Reactions of EMS with carbon dioxide and acetone gave products with carbonate and ketonide functional groups, respectively. The complex mixture of compounds present in the product, EMS(MeOH), resulting from the reaction of EMS with MeOH, was characterized by MS and NMR investigations. In addition to products resulting from MeOH addition across the epoxide ring, were major amounts of cyclic tetrahydrofuran derivatives that were derived from reactions of methyl linoleate (18:2) with MeOH. All of the solvents were characterized by high boiling points and low vapor pressures. Their viscosities were higher than that of methyl soyate. Especially notable were their very high Kauributanol values, which ranged from 280 to 852, all of which are much higher than that (57) of methyl soyate. Such high KB values indicate that these solvents have very favorable solubilizing properties, which is illustrated by the ability of EMS(MeOH) to readily dissolve both polar (e.g., MeOH) and non-polar (e.g., hexane) compounds.
- Riley, Sean J.,Verkade, John G.,Angelici, Robert J.
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- 2-Chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane, a Reagent for the Accurate Determination of the Uncondensed and Condensed Phenolic Moieties in Lignins
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The use of 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane as a phosphitylation reagent in quantitative 31P NMR analysis of the hydroxyl groups in lignins has been thoroughly examined, and an experimental protocol recommended for spectra acquisition has been developed.Quantitative analysis of six "standard lignins" gave results comparable to those obtained by other methods of analysis.Excellent resolution of the various phenolic hydroxyl environments including those present in condensed moieties was observed.Hovever, this was at the expense of resolution in the aliphatic hydroxyl region, where no distinction between primary, secondary, and the erythro and threo forms of the secondary hydroxyls of the β-O-4 bonds can be made. Keywords: Analysis; aromatic groups, hydroxyls; lignins; nuclear magnetic resonance (NMR); phenols; phosphorus; quantitative
- Granata, Alessandro,Argyropoulos, Dimitris S.
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- Determination of water content in olive oil by 31P NMR spectroscopy
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A method for moisture determination in olive oil using 31P NMR spectroscopy is developed. This method is based on the replacement of the hydrogen atoms of water molecules with the tagging agents 2-chloro-4,4,5,5- tetramethyl-1,3,2-dioxaphospholane and diphenylphosphinic chloride. Both reagents were successful in determining moisture in olive oil. However, only the second reagent provided a clean and instantaneous reaction under mild condition with no side reactions as observed with the first reagent. A study comparison was made to assess the agreement between the present analytical NMR method and the well-established methods of Karl Fischer titration.
- Hatzakis, Emmanuel,Dais, Photis
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- α CETOPHOSPHONATES ET ESTERS CYCLIQUES D'HYDROXYMETHYLENES DIPHOSPHONATES SYNTHESES, STRUCTURES ET HYDROLYSE
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Synthesis of symmetrical diesters derived from hydroxy methylene diphosphonic acids 1 to 8 is described either in one step or via the corresponding α ketophosphonate 1a to 8a.Study of the diphosphonates (1 to 6) -> phosphate-phosphonates (1b to 6b) isomerization has been realized.Results related to peculiar cases in connection with nonsymmetrical esters 10, 11, 17 and study of the hydrolysis reaction of diphosphonates are presented.
- Tromelin, Anne,El Manouni, Driss,Burgada, R.
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p. 301 - 312
(2007/10/02)
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