613-03-6Relevant articles and documents
Spectrophotometric determination of cobalt(II) and cyanocobalamin with vanillilfluorone and its applications
Hoshino, Mitsuru,Matsushita, Momoka,Samma, Megumi,Asano, Mamiko,Yamaguchi, Takako,Fujita, Yoshikazu
, p. 721 - 724 (2011)
Spectrophotometric determination of cobalt(II) was accomplished with vanillilfluorone (VF) in the presence of dimethylbenzyltetradecylammonium chloride (Zephiramine, Zep). In the determination of cobalt(II), Beer's law was obeyed in the range of 24-470 ng/ml, with an effective molar absorption coefficient (at 575 nm) and relative standard deviation of 1.35×105 l mol-1 cm-1 and 0.66% (n=5), respectively. The composition ratio of the colored complex was determined by the mole ratio and continuous variation methods, and it was found to be Co(II) :VF: Zep=1 : 2 : 4. Analysis of cyanocobalamin by the same procedure showed that cyanocobalamin could be determined in the concentration range of 0.5-0.11 μg/ml using the proposed method.
Direct Acetoxylation of Arenes
Hong Nguyen, Thi Anh,Hou, Duen-Ren
supporting information, p. 8127 - 8131 (2021/08/23)
Acetoxylation of arenes is an important reaction and an unmet need in chemistry. We report a metal-free, direct acetoxylation reaction using sodium nitrate under an anhydrous environment of trifluoroacetic acid, acetic acid, and acetic anhydride. Arenes (31 examples), with oxidation potentials (Eox, in V vs SCE) lower than benzene (2.48 V), were acetoxylated with good yields and regioselectivity. A stepwise, single electron-transfer mechanism is proposed.
Synthetic method of medical intermediate 1,2,4-triacetoxybenzene
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Page/Page column 3-7, (2018/09/08)
The invention discloses a synthetic method of a medical intermediate 1,2,4-triacetoxybenzene. The synthetic method comprises the following steps: adopting acetic anhydride, concentrated sulfuric acid,p-benzoquinone, Co(NO3)2.6H2O, DMF, 2-methylimidazole and zinc oxide as main raw materials, adopting cobalt nitrate hexahydrate Co(NO3)2.6H2O and 2-methylimidazole to ultrasonically synthesize a nanocatalyst, and using the nano catalyst to catalyze the reaction of acetic anhydride and p-benzoquinon, so that a generated skeleton carrier ZIF material is uniform in particle size and small in crystal grain size; by loading metal ions Zn, the activity of reactants can be improved, and the activation time of the reactants can be greatly reduced; and the raw materials are mixed in the followingratios: a weight ratio of acetic anhydride to p-benzoquinone is 11:3; a weight ratio of the catalyst to active carbon is 4:3; the weight ratio of cobalt nitrate hexahydrate to 2-methylimidazole is 5:4; a weight ratio of ZnO powder to ZIF-67 is 1:2. By adopting the synthetic method, the heat release rate is effectively controlled, the synthetic process is performed under a mild condition, the generation of the side reaction and the waste of raw materials can be reduced, the conversion rate of a target product is increased, and an excellent catalytic effect for the synthetic reaction of 1,2,4-triacetoxybenzene can be achieved.
9. 9 '- (3, 3' - dihydroxy - 4, 4' - b phenylate base) double-phenylfluorone reagent and its preparation method and application
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Paragraph 0020; 0023, (2017/11/16)
The invention belongs to the technical field of phenylfluorone compounds and provides a 9,9'-(3,3'-dihydroxy-4,4'-diphenylether)bifluorone reagent and a preparation method and application thereof to solve the problem that an existing phenylfluorone compound having non-ideal sensitivity and selectivity is unable to serve as a fluorescent reagent in the fluorescent detection of metal ions.Two pyranoid ring structural units are introduced in molecules, the quantity of metal ion coordination sites is increased by one time, the ability of the reagent to coordinate with metal ions is enhanced, and the fluorescent reagent good in sensitivity and selectivity is obtained.The preparation method is simple, the cost is low, properties are stable, a detection limit in nickel determination by fluorophotometric quenching process in a basic medium in the presence of a surfactant is lower that of other reagent quenching processes, cobalt determination by spectrophotometry is higher than other fluorone reagent processes in sensitivity, and a detection limit in cobalt determination by discoloring spectrophotometry is lower than that of a process using other fluorone reagents.This reagent has high detection speed for nickel and cobalt ions and is good in selectivity, high in sensitivity and high in complex stability.
