Aims: Research of the convenient method for obtaining (RS)-1-(4-Hydroxymethyl-phenoxy)- 3-isopropylaminopropan-2-ol, known as the Impurity A of Bisoprolol, of high purity as close as 100%.
Study Design: Impurity A may be formed as a by-product in the processes used for commercial synthesis of bisoprolol fumarate. Impurity A may be also formed as a result of degradation (hydrolysis) of active substance. This compound is available as the reference standard, but the offered purity is between 95% and 97%, what suggest that its purification to the pharmaceutical quality is demanding. The most common method of purification of chemical standards for pharmacy is preparative chromatography and is commonly used for obtaining the reference standards of high purity, but it is unattainable in many cases, so there is a need for simple, convenient and repeatable laboratory procedures elaboration.
Place of Study: ICN Polfa Rzeszów S.A., Poland, Synthesis Laboratory.
Methodology: The synthesis of Bisoprolol Impurity A was performed starting from p-hydroxybenzyl alcohol and subsequent reactions with epichlorohydrin and isopropylamine, whereas purification process consisted particularly of obtaining and isolation of fumarate salt of Impurity A, its crystallization and basification.
Results: The analytical standard of Bisoprolol Impurity A of a purity of 95.5% was obtained with convenient chemical process without need of any advanced methodology. The structure was elucidated with IR, NMR and EA methods and the purity was determined by HPLC technique.
Conclusion: The method of obtaining the analytical standard of Impurity A of purity as close as 100% is described in this paper.
4-Methylquinazoline was synthesized with 2-aminoacetophenone and formamide as the starting materials. The reaction conditions, including catalyst, ratio of substrates, temperature and time were optimized. Results showed that the optimal condition were as follows: Catalyst BF3-Et2O, the molar ratio of 2-aminoacetophenone: BF3-Et2O = 1:0.5, the weight ratio of 2-aminoacetophenone: formamide = 1:52, temperature 150°C, and time 6 h. Under the optimal conditions, the yield of the reaction achieved the highest (86%), which are better than the past reports.
Spent catalysts, chemical traps and sorbents are types of solid wastes generated worldwide, which contain potentially valuable or environmentally hazardous materials that need to be recovered before final deposition. Chlorination and electrolysis are unit processes applied in extractive metallurgy for metal extraction from poly-metallic or low-grade ores. The primary aim of this study was to assess the possibility of applying pyrometallurgy (chlorination) and electrometallurgy to spent chemical sorbents used as sulfur traps and to recover zinc. The spent sorbents may include zinc in different phases: ZnO, ZnS and Zn0.65Al 0.35(OH)2(CO3)0.167(H2O)0.5. It was found that 96.8% of the zinc can be separated by dry chlorination at 475ºC with pure chlorine. Before chlorination, addition of CaCO3 (17 wt.%) is necessary to prevent formation of ZnSO4. The zinc chloride obtained is dissolved in water and electrolyzed to generate chlorine which can be recycled to the chlorination reactor, and metallic zinc as a non-adherent layer on the cathode. The electrolyte composition is 65 g.L−1 ZnCl2 with 20 g.L−1 H3BO3 and 200 g.L−1 KCl. It is possible to recover pure zinc (99.9 wt.%) from chemical sorbents with the methodology proposed. These results are important for the development of new and more efficient recovery strategies to prevent environmental damage and obtain valuable elements from wastes.
Transesterification and Epoxidation of oils extracted from seeds of five different plants, namely, Jatropha, Moringa, Castor, Cotton and Shea was carried out using standard methods and characterized using American Society for Testing Material (ASTM) standard tests. The oils were tested on both low and high- medium voltage transformer and the result showed that their dielectric strength ranges from 25 – 43 KV, while the free fatty acids were found to be within the range of 0.01 – 0.008 mg KOH. These results are within the range of ASTM standards and that the oil samples have potentials to serve as bio-transformer oils.
A Mixture of 10wt% CuO-10wt% Fe2O3supported on cordierite and CeO2-doped (0.75-3 mol%) were prepared by wet impregnation. The effects of calcination temperatures (500, 700 and 900°C) and doping ratio on the crystalline phase, morophology, surface area were investigated by XRD, HR-TEM, N2-adsoprtion-desorption. Moreover, their photocatalytic activities of samples calcined at 700°C on the degradation of a mixture of phenol, 4-choloro-phenol and cresol were evaluated under UV irradiation. CeO2-doping led to a progressive increase in SBET. Sample treated with 0.75 mol% CeO2 and calcined at 700°C had the best photocatalytic activity. This might be attributed to the presence of un-reacted oxides (CuO and Fe2O3) which have low redox potentials.