121-87-9Relevant articles and documents
Kinetic study and mechanism of Niclosamide degradation
Zaazaa, Hala E.,Abdelrahman, Maha M.,Ali, Nouruddin W.,Magdy, Maimana A.,Abdelkawy
, p. 655 - 662 (2014)
A spectrophotometric kinetic study of Niclosamide alkaline degradation as a function of drug concentration, alkaline concentration and temperature has been established utilizing double divisor-ratio spectra spectrophotometric method. The developed method allowed determination of Niclosamide in presence of its alkaline degradation products; namely; 2-chloro-4-nitro aniline (DEG I) and 5-chloro salicylic acid (DEG II) with characterization of its degradation mechanism. It was found that degradation kinetic of Niclosamide followed pseudo-first order under the established experimental conditions with a degradation rate constant (k) of 0.0829 mol/h and half life (t1/2) of 8.35 h. The overall degradation rate constant as a function of the temperature under the given conditions obeyed Arrhenius equation where the activation energy was calculated to be 3.41 kcal/mol.
Sodium lauryl sulfate-catalyzed oxidative chlorination of aromatic compounds
Mahajan, Tanu,Kumar, Lalit,Dwivedi, K.,Agarwal, D. D.
, p. 3655 - 3663,9 (2012)
Chlorination of commercially important aromatic compounds using sodium chloride as chlorine source and sodium periodate as oxidant in acidic medium catalyzed by sodium lauryl sulfate (SLS) led to the chloro-substituted aromatics in good yields and purity. Addition of sodium lauryl sulfate led to increased chlorination rate, better yield, excellent purity, and better quality of end product. The advantages of the present method are greater yield, excellent purity, and shorter reaction time at room temperature. Also dichlorinated product can be obtained by increasing the amount of sodium chloride and sodium periodate at slightly higher temperature (40C).
Activator free, expeditious and eco-friendly chlorination of activated arenes by N-chloro-N-(phenylsulfonyl)benzene sulfonamide (NCBSI)
Misal, Balu,Palav, Amey,Ganwir, Prerna,Chaturbhuj, Ganesh
supporting information, (2021/01/04)
N-Chloro-N-(phenylsulfonyl)benzene sulfonamide (NCBSI) has been explored for the first time as a chlorinating reagent for direct chlorination of various activated arenes and heterocycles without any activator. A comparative in-silico study was performed to determine the electrophilic character for NCBSI and commercially available N-chloro reagents to reveal the reactivity on a theoretical viewpoint. The reagent was prepared by an improved method avoiding the use of hazardous t-butyl hypochlorite. This reagent was proved to be very reactive compared to other N-chloro reagents. The precursor of the reagent N-(phenylsulfonyl)benzene sulfonamide was recovered from aqueous spent, which can be recycled to synthesize NCBSI. The eco-friendly protocol was equally applicable for the synthesis of industrially important chloroxylenol as an antibacterial agent.
Complementary Site-Selective Halogenation of Nitrogen-Containing (Hetero)Aromatics with Superacids
Mamontov, Alexander,Martin-Mingot, Agnès,Métayer, Benoit,Karam, Omar,Zunino, Fabien,Bouazza, Fodil,Thibaudeau, Sébastien
supporting information, p. 10411 - 10416 (2020/07/30)
Site-selective functionalization of arenes that is complementary to classical aromatic substitution reactions remains a long-standing quest in organic synthesis. Exploiting the generation of halenium ion through oxidative process and the protonation of the nitrogen containing function in HF/SbF5, the chlorination and iodination of classically inert Csp2?H bonds of aromatic amines occurs. Furthermore, the superacid-promoted (poly)protonation of the molecules acts as a protection, favoring the late-stage selective halogenation of natural alkaloids and active pharmaceutical ingredients.