256-96-2Relevant articles and documents
Stability indicating spectrophotometric methods for quantitative determination of carbamazepine and its degradation product, iminostilbene, in pure form and pharmaceutical formulations
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A stressed study on the stability and degradation behavior under ICH forced degradation conditions of most widely used antiepileptic drug; carbamazepine (CMZ) is presented in this work. The research also includes studying spectrophotometric nature of CMZ and assaying it with mostly used spectrophotometric techniques. Six simple and sensitive spectrophotometric methods are introduced as stability indicating methods for quantitative determination of CMZ and its degradation product, one of its reported potential impurities; iminostilbene (IMS). Dual wavelength is method I where two wavelengths (215 and 270 nm for CMZ and 258 and 307 nm for IMS) were chosen for each component while absorbance difference is zero for the second one. Method II is isoabsorptive point method where the absorbance of CMZ at A225 nm was measured in the range of 0.5–20 μg mL?1. Method III is second derivative method which allows simultaneous determination of CMZ at 247 nm and IMS at 273 nm without any interference. Method IV based on measuring the peak amplitude of first derivative of ratio spectra (1DD) at 280.5 and 253 nm for determination of CMZ and IMS, respectively. Method V is mean centering of the ratio spectra with good linearity for CMZ and IMS over 200–330 nm. Ratio difference method is method VI where good linearity was achieved for determination of CMZ and IMS by measuring differences in the amplitude of ratio spectra at 285, 258 nm and 258, 285 nm, respectively. The proposed methods show successful application in CMZ's pharmaceutical formulations.
Method for synthesizing iminostilbene
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Paragraph 0018-0033, (2021/03/11)
The invention discloses a method for synthesizing iminostilbene, which comprises the following steps: by using 1-phenylindole as a starting raw material, carrying out intramolecular rearrangement reaction on 1-phenylindole under the action of a composite acidic catalytic system to generate iminostilbene; wherein the composite acidic catalytic system is formed by mixing a phosphorus-containing acidic substance and a sulfur-containing acidic substance, the phosphorus-containing acidic substance is one or more of polyphosphoric acid, phosphoric acid and phosphorus pentoxide, and the sulfur-containing acidic substance is one or more of sulfuric acid, methanesulfonic acid and p-toluenesulfonic acid. The phosphorus-containing acidic substance and sulfur-containing acidic substance are used together to form the composite acidic catalytic system, the catalytic system is used in a reaction for catalytic synthesis of iminostilbene, corresponding reaction conditions are optimized, reaction time is shortened, side reactions are reduced, and therefore the method has the advantages of being high in product yield, short in reaction time and the like. The highest yield of the product reaches 83.4%, the purity is 99%, and a good technical effect is achieved.
Chemical synthesis, spectroscopic studies, chemical reactivity properties and bioactivity scores of an azepin-based molecule
Kollur, Shiva Prasad,Castro, Joaquín Ortega,Frau, Juan,Glossman-Mitnik, Daniel
, p. 300 - 306 (2018/12/13)
Azepines derived molecules are of great interest because of their multi-drug like properties and thus advantageous in biomedical field. Herein, a novel route is described for the synthesis of an azepine-based molecule, 10,11-Dibromo-10,11-dihydro- 5H-dibenzo[b,f]azepine-5-carbonyl chloride (DACC) by using dibutyltin dilaurate (DBTDL) as catalyst. The structure of DACC was elucidated by using FT-IR, NMR, and mass spectroscopic techniques. Several density functionals were considered for the study of the molecular properties of the synthesized compound. The global and local reactivity descriptors were estimated by using Conceptual Density Functional Theory (CDFT). The active sites suitable for the nucleophilic and electrophilic attacks were selected by linking them with the Fukui indices, Parr functions and condensed Dual Descriptor Δf(r). Finally, the bioactivity scores for the studied molecule were predicted through different methodologies.