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Microwave-Assisted Green Chemistry Approach
Published in Banik Bimal Krishna, Bandyopadhyay Debasish, Advances in Microwave Chemistry, 2018
Biswa Mohan Sahoo, Bimal Krishna Banik, Jnyanaranjan Pa
The synthesis of benzocaine derivatives was carried out by the condensation of urea, thiourea, semicarbazide and thiosemicarbazide with ethyl-4[(chloroacetyl)amino]benzoate under microwave irradiation in the presence of ethanol. The antimicrobial activities of the synthesized compounds are studied by the disc diffusion method, as given in Table 12.10. The zone of inhibition is measured in mm to estimate the potency of the test compounds [70].
Name Reactions
Published in Benny K.G. Theng, Clay Mineral Catalysis of Organic Reactions, 2018
Singh et al. (2009) reported the formation of isatin-3-thiosemicarbazones and N-Mannich bases by reacting isatins with thiosemicarbazide and their thiosemicarbazone with a secondary amine in the presence of K10 montmorillonite under microwave irradiation. The K10-catalyzed synthesis of various Mannich bases has been summarized by Kaur and Kishore (2012).
Atomic Absorption Spectrometry and Related Techniques
Published in Grinberg Nelu, Rodriguez Sonia, Ewing’s Analytical Instrumentation Handbook, Fourth Edition, 2019
Bernhard Welz, Maria Goreti R. Vale
Knowledge of this mechanism makes it possible to take several measures in order to avoid or correct for these interferences. The first one, which has been applied empirically long before the mechanism was known, is the use of masking agents such as ethylendiamine tetraacetic acid, thiourea, citric acid, pyridine-2-aldoxime, l-cysteine, thiosemicarbazide, and so on, which form complexes with the concomitant metal ions and hence prevents their reduction to the interfering species. Another possibility is an increase of the acid concentration of the measurement solution and/or a decrease of the sodium tetrahydroborate concentration. The former increases the solubility of the metal; the latter avoids or delays the reduction of the metal ion and its precipitation. As the reduction of the analyte to the hydride is always the fastest process (maybe except for the pentavalent forms of antimony and arsenic), it is often sufficient to retard the reduction of the transition metal ion until the hydride is released from the solution. This technique, called kinetic discrimination has been most successfully used in flow systems, where the reaction time can be precisely controlled via the length of the reaction coil. A third possibility is the addition of an electrochemical buffer, which is reduced preferentially, and the reduced form of which does not interfere with the hydride. Iron(III) has been proposed for this purpose to eliminate the interference of nickel on the determination of several hydride-forming elements in steel (Welz and Melcher, 1984). The potentials of possible reduction reactions that can take place when sodium tetrahydroborate is added to a solution containing Fe(III) and Ni(II) are listed in Table 4.5. As a result of the electrochemical potentials Fe(III) is initially reduced to Fe(II) before Ni(II) is reduced to the metal and precipitated. The same buffer has also been used for the suppression of the interference of copper on the determination of selenium (Bye, 1987).
Synthesis, characterization and antimicrobial activity of novel silver nanoparticles functionalized with nitrogenous ligands
Published in Inorganic and Nano-Metal Chemistry, 2023
B. Varun Kumar, K. Hussain Reddy
The ligand was prepared by using thiosemicarbazide and 4-hydroxybenzaldehyde. Ethanolic solutions (20 mL each) of thiosemicarbazide (3.75 g; 0.04 mol) and 4-hydroxybenzaldehyde (5 g; 0.04 mol) were mixed in a round bottom flask. Two drops of CH3COOH were added to the reaction mixture. This reaction mixture was heated under reflux for 30 minutes and cooled to room temperature. A light brown colored crystalline solid was formed. It was collected by filtration, washed with water and methanol and then dried in vacuum. Yield 74%; m.p. 216–218 °C; BTSC was characterized based on its FT-IR (Figure S1), 1H-NMR (Figure S2) and mass spectra (Figure S3); FT-IR (cm−1); 3494(νNH2(sym) 3469(νNH2(asym), 3376 & 3360 (νC-H (υC-H methine), 3130 (νO-H), 1609 (νC = N), 1164(νC = S); 1H-NMR; δ 9.88(s, 1H O-H), 7.83 (s, 1H, C-H), 7.33–7.61 (d, 2H, Ar-H), 6.76–6.78 (d, 2H, Ar-H), 7.94 and 8.07 (–NH2), 11.25 (s,1H, N-H. (s); mass spectra (m/z). Most intense peak was observed at 196 which corresponded to (M + H). The synthesis of the BTSC ligand is shown in Figure 1.
Biological evaluation of copper(II) complexes on N(4)−substituted thiosemicarbazide derivatives and diimine co-ligands using DNA interaction, antibacterial and in vitro cytotoxicity
Published in Journal of Coordination Chemistry, 2019
Neelaveni Rajendran, Abirami Periyasamy, Nithya Kamatchi, Vasantha Solomon
All the chemicals such as 4-methoxy-1-naphthaldehyde, 4-methyl-3-thiosemicarbazide, 4-ethyl-3-thiosemicarbazide, 4-phenyl-3-thiosemicarbazide, 1,10-phenanthroline and 2,2′-bipyridyl were purchased from Sigma-Aldrich (USA) and copper(II) chloride, ethidium bromide (EB), Tris–HCl, agarose (molecular biology grade) procured from Merck (USA). 3-(4,5-Dimathylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was purchased from Hi media (India). All the commercial solvents were purified before the preparation of ligand and complex. The pUC18 DNA was obtained from Bangalore GeNei (India) and stored at −20 °C. All the buffer solutions used for DNA cleavage studies were prepared from Milli-Q water. HeLa cell line was purchased from the National Centre for Cell Science (NCCS) Pune, India. The cells were preserved in Minimum Essential Medium (MEM) supplemented with a few antibiotics (100 units of penicillin, 100 μg mL−1 of streptomycin and 10% fetal bovine serum [FBS]) and the culture were grown-up in a humidified atmosphere 5% CO2 incubator at 37 °C (Brunswick, Germany).
Synthesis and characterization of new thiosemicarbazonato molybdenum(VI) complexes and their in vitro antimicrobial activities
Published in Journal of Coordination Chemistry, 2019
Şenol Çelen, Songül Eğlence-Bakır, Musa Şahin, Inci Deniz, Hayati Celik, Irfan Kizilcikli
Thiosemicarbazones are a very important class of compounds in coordination chemistry. They have been extensively investigated due to their ability to form a chelate [1] with metals and their broad spectrum biological activity [2–4]. Thiosemicarbazone is the product of thiosemicarbazide, a precursor and a carbonyl compound such as an aldehyde or a ketone [5]. After coordination, there are two options for the condensation of the amidic nitrogen of the thiosemicarbazone molecule; either N4-aryl/alkyl thiosemicarbazide may be used as the starting compound [6] or the carbonyl compounds may coordinate to the nitrogen by the orientation effect of some metal centers during complexation process and this is called the template reaction [7]. An alternative way to obtain different derivatives is substitution on the sulfur [8, 9].