- Disalicylate synthesis process
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The invention discloses a novel environment-friendly disalicylate synthesis process. The process comprises the following steps: taking salicylic acid as a raw material and an organic solvent as a solvent, dissolving the salicylic acid in the organic solvent at normal pressure, dropwise adding diethylamine to form salicylic acid diethylamine salt, performing condensation reaction by utilizing polyphosphoric acid to generate a mixture of disalicylate and diethylamine phosphate, distilling off the organic solvent, adding water for hydrolysis to obtain water-insoluble disalicylate and a diethylamine phosphate solution, and neutralizing the diethylamine phosphate solution with an alkali to easily obtain trisodium phosphate crystals and diethylamine, so that no sodium chloride solid waste is generated. The yield is more than 95%, and the purity is more than or equal to 99% (HPLC). Compared with a traditional process, phosphorus trichloride or phosphorus oxychloride is not used, the obtainedtrisodium phosphate can be used for producing sodium hexametaphosphate, the production efficiency is greatly high, the cost is low, and industrial production is easy.
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Paragraph 0026-0031
(2020/08/02)
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- Dehydration induced by intramolecular redox character of a stable allylidenetributylphosphorane
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An air and moisture stable P-ylide, dimethyl fluorenylidenetributylphosphoranylidenesuccinate acts as a new type of dehydrating agent for synthesizing acid anhydride, ester, and amide. The ylide is most suitable for inducing these reactions in analogous P-ylides. The reaction is considered to be caused by internal reductive and oxidative nature of the P-ylide.
- Kawamura, Yasuhiko,Sato, Yoshinori,Horie, Tokunaru,Tsukayama, Masao
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p. 7893 - 7896
(2007/10/03)
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- Evaluation of glycolamide esters and various other esters of aspirin as true aspirin prodrugs
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A series of glycolamide, glycolate, (acyloxy)methyl, alkyl, and aryl esters of acetylsalicylic acid (aspirin) were synthesized and evaluated as potential prodrug forms of aspirin. N,N-Disubstituted glycolamide esters were found to be rapidly hydrolized in human plasma, resulting in the formation of aspirin as well as the corresponding salicylate esters. These in turn hydrolyzed rapidly to salicylic acid. The largest amount of aspirin formed from the esters were 50 and 55% in case of the N,N-dimethyl- and N,N-diethylglycolamide esters, respectively. Similar results were obtained in blood with the N,N-dimethyl- and N,N-diethylglycolamide esters. Unsubstituted and monosubstituted glycolamide esters as well as most other esters previously suggested to be aspirin prodrugs were shown to hydrolyze exclusively to the corresponding salicylic acid esters. Lipophilicity parameters and water solubilities of the esters were determined, and structural factors favoring ester prodrug hydrolysis at the expense of deacetylation to yield salicylate ester are discussed. The properties of some N,N-disubstituted glycolamide esters of aspirin are highlighted with respect to their use as potential aspirin prodrugs.
- Nielsen,Bundgaard
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p. 727 - 734
(2007/10/02)
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- Solid-state stability of aspirin in the presence of excipients: Kinetic interpretation, modeling, and prediction
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Salicylsalicylic acid and acetylsalicylsalicylic acid were identified as decomposition products of aspirin when mixtures of the drug, with magnesium stearate, were stored in the solid state at 60° and 75% relative humidity. The effect of increasing the concentration of magnesium stearate and the addition of other alkali stearates on the rate of decomposition of aspirin were studied. The validity of the theory that pH changes induced by the alkali stearates account for the catalytic effect of the lubricants on the decomposition was tested. The changes observed were modeled and the mechanism involved elucidated. The potential use of the melting points of aspirin mixtures in predicting the stability of the drug in such drug-excipient mixtures is demonstrated.
- Mroso,Li Wan Po,Irwin
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p. 1096 - 1101
(2007/10/02)
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