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Chemistries of Chemical Warfare Agents
Published in Brian J. Lukey, James A. Romano, Salem Harry, Chemical Warfare Agents, 2019
Terry J. Henderson, Ilona Petrikovics, Petr Kikilo, Andrew L. Ternay Jr., Harry Salem
Chloropicrin is stable in cold, dilute aqueous sodium hydroxide and does not decompose rapidly in either cold water or cold mineral acids (hydrochloric acid, for example). It slowly decomposes in ethanolic potassium hydroxide, however, and undergoes more rapid decomposition with sodium ethoxide or ethanolic sodium cyanide. Chloropicrin also decomposes slowly in acetone solutions, which is accompanied by a concomitant deposit of ammonium chloride. As with many other highly chlorinated organic compounds, the stability of chloropicrin decreases in the presence of light, as evidenced by the formation of color in its benzene solutions.
Chemistry
Published in Stephen P. Coburn, The Chemistry and Metabolism of 4′-Deoxypyridoxine, 2018
In conjunction with our attempts to identify the metabolites of deoxypyridoxine, we employed the following reactions for selectively blocking either the 3- or 5′-position.92 Ethyl chloroformate will react only with the phenol group of 4′-deoxypyridoxine. In a typical example, 1 g (5.25 mmol) of deoxypyridoxine hydrochloride was dissolved in 700 ml of tetrahydrofuran (redistilled over ferrous sulfate to remove peroxides) containing 1.5 mi (10.8 mmol) of triethylamine. Absorbance at 315 nm was used to determine when solution was complete. Ethylchloroformate 0.55 ml (5.8 mmol) was added with stirring. Stirring at room temperature was continued for 15 to 30 min after the yellow color faded. After filtering off the precepitated triethylammonium chloride, the solvent was removed in vacuo leaving a yellowish oil. The lack of absorbance at 315 nm indicated that the reaction was quantitative. If desired, the hydrochloride could be isolated by dissolving the oil in ethanol containing a stoichoimetric amount of hydrochloric acid and crystallizing with ether (M.P. 180°C decomposition). If further syntheses were planned, it was more convenient to leave it as the free base. For larger scale preparations of this derivative, it was more convenient to use absolute alcohol as the solvent and sodium ethoxide as the base.
Influences of different sugar ligands on targeted delivery of liposomes
Published in Journal of Drug Targeting, 2020
Changmei Zhang, Zhong Chen, Wenhua Li, Xiaoying Liu, Shukun Tang, Lei Jiang, Minghui Li, Haisheng Peng, Mingming Lian
Compound 3a (2.0 g, 5 mmol), methanol (20 ml) were added into the three-neck bottle in turn at the argon gas environment. Then sodium methoxide (1.4 g, 25 mmol) was added into the mixture to react overnight at room temperature. Acetic acid (1.8 ml, 30 mmol) was added and stirred for 10 min. Compound 4a was purified by ion-exchange resin column chromatography to rotate to dry. Compound 4a was a white semi-oil and semi-solid product (1.1 g) with a yield of 94.3%. The nearly identical synthesis conditions of 4 b, 4c, 4d and 4e were carried out.
Mesoporous tantalum oxide nanomaterials induced cardiovascular endothelial cell apoptosis via mitochondrial-endoplasmic reticulum stress apoptotic pathway
Published in Drug Delivery, 2023
Yuanyong Jiao, Xiwei Zhang, Hongyu Yang, Hao Ma, Junjie Zou
For the fabrication of mTa2O5 nanomaterials, CTAB (640 mg) and EtOH (3.2 mL) were mixed with an aqueous solution (40 mL). At room temperature, stirring continuously, EtOH (7.2 mL) containing tantalum ethoxide (120 µL) was added. After 3-h continuous stirring, the fabricated mTa2O5 nanomaterials were centrifuged (15,000 rpm) and rinsed with distilled water thrice to eliminate excess CTAB. The obtained nanomaterials were ultrasonically distributed in EtOH solution.