27030-98-4Relevant academic research and scientific papers
A Green, Scalable, One-Minute Synthesis of Benzimidazoles
Elumalai, Vijayaragavan,Hansen, Jorn H.
supporting information, p. 547 - 552 (2020/03/27)
Herein is reported a substantially improved synthesis of 2-substituted benzimidazoles by condensation of 1,2-diaminoarenes and aldehydes using methanol as the reaction medium. The developed method afforded moderate to excellent yields (33-96percent) at am
New synthesis method of thiabendazole
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Paragraph 0026; 0035; 0036; 0037; 0038; 0184; 0185, (2020/02/20)
The invention relates to a new synthetic route of a drug commonly named as thiabendazole. Thiazole-4-formaldehyde is used as a raw material, and is condensed with hydroxylamine hydrochloride to obtainthiazole-4-formaldoxime, thiazole-4-formaldoxime is subjected to chlorination by using NCS, and then reacts with aniline to obtain N-phenylthiazole-4-methylamine oxime, then N-phenylthiazole-4-methylamine oxime reacts with p-trifluoromethyl benzoyl chloride to obtain an amidoxime ester, and finally a visible-light-catalyzed free radical reaction is adopted for cyclization to obtain thiazole. According to the method, the visible-light-catalyzed free radical reaction is used to the synthesis of thiabendazole for the first time, the reaction conditions of a high temperature and a strong acid inthe traditional synthesis method are avoided, and thereby the reaction is greener and milder. The method has a broad spectrum, and can also be used for synthesis of imidazole compounds Ia-Ial.
Formation of Amidinyl Radicals via Visible-Light-Promoted Reduction of N-Phenyl Amidoxime Esters and Application to the Synthesis of 2-Substituted Benzimidazoles
Li, Gang,He, Ru,Liu, Qiang,Wang, Ziwen,Liu, Yuxiu,Wang, Qingmin
, p. 8646 - 8660 (2019/07/08)
We have developed a new method for the synthesis of 2-substituted benzimidazoles via amidinyl radicals generated by visible-light-promoted reduction of N-phenyl amidoxime esters in the presence of an iridium photocatalyst. This is the first report of the use of N-phenyl amidoxime esters as amidinyl radical precursors, and the first use of substituted benzene rings as amidinyl radical acceptors. This method widens the application range of substrates and overcomes the shortcomings of the traditional methods for the synthesis of 2-substituted benzimidazoles, which requires harsh reaction conditions, involves difficult-to-prepare substituted o-phenylenediamine substrates, and produces acidic waste.
Aqueous 1M glucose solution as a novel and fully green reaction medium and catalyst for the oxidant-free synthesis of 2-arylbenzimidazoles
Rostamizadeh, Shahnaz,Aryan, Reza,Ghaieni, Hamid Reza
experimental part, p. 1794 - 1804 (2011/06/24)
The reaction of various o-phenylenediamines and substituted benzaldehydes was carried out in 1M glucose solution as reaction medium and catalyst under one-pot oxidantfree conditions. The desired products were obtained at 60 °C with good to excellent yields, and the reaction was performed chemoselectively without formation of 1,2-disubstituted benzimidazoles. No need for any extra oxidant, simple workup, and use of carbohydrates as fully green promoters are some advantages of the present work.
Rh(I)-catalyzed arylation of heterocycles via C-H bond activation: Expanded scope through mechanistic insight
Lewis, Jared C.,Berman, Ashley M.,Bergman, Robert G.,Ellman, Jonathan A.
, p. 2493 - 2500 (2008/09/18)
A practical, functional group tolerant method for the Rh-catalyzed direct arylation of a variety of pharmaceutically important azoles with aryl bromides is described. Many of the successful azole and aryl bromide coupling partners are not compatible with methods for the direct arylation of heterocycles using Pd(O) or Cu(I) catalysts. The readily prepared, low molecular weight ligand, Z-1-tert-butyl-2,3,6,7-tetrahydrophosphepine, which coordinates to Rh in a bidentate P-olefin fashion to provide a highly active yet thermally stable arylation catalyst, is essential to the success of this method. By using the tetrafluoroborate salt of the corresponding phosphonium, the reactions can be assembled outside of a glovebox without purification of reagents or solvent. The reactions are also conducted in THF or dioxane, which greatly simplifies product isolation relative to most other methods for direct arylation of azoles employing high-boiling amide solvents. The reactions are performed with heating in a microwave reactor to obtain excellent product yields in 2 h.
Antitumor benzothiazoles. 7. Synthesis of 2-(4- acylaminophenyl)benzothiazoles and investigations into the role of acetylation in the antitumor activities of the parent amines
Chua, Mei-Sze,Shi, Dong-Fang,Wrigley, Samantha,Bradshaw, Tracey D.,Hutchinson, Ian,Shaw, P. Nicholas,Barrett, David A.,Stanley, Lesley A.,Stevens, Malcolm F. G.
, p. 381 - 392 (2007/10/03)
2-(4-Aminophenyl)benzothiazoles display potent and selective antitumor activity against inter alia breast, ovarian, colon, and renal cell lines, but their mechanism of action, though yet to be defined, may be novel. Metabolism is suspected to play a central role in the mode of action of these benzothiazoles since drug uptake and biotransformation were observed in sensitive cell lines (e.g., breast MCF-7 and MDA 468 cells) in vitro, whereas insensitive cell lines (e.g., prostate PC 3 cells) showed negligible uptake and biotransformation. N-Acyl derivatives of the arylamines have been synthesized, and in vitro studies confirm N-acetylation and oxidation as the main metabolic transformations of 2-(4-aminophenyl)benzothiazoles. With the predominant process being dictated by the nature of the 3'-substituent. The prototype amine 3 underwent mainly N-acetylation in vitro, while 3'- substituted analogues 4 and 5 were primarily oxidized. N-Acetylation of 4 to 11 exerts a drastic dyschemotherapeutic effect in vitro, but acetylation of the halogeno congeners 5-7 gave acetylamines 12-14 which substantially retain selective antitumor activity. In vivo pharmacokinetic studies in rats confirmed rapid and exclusive N-acetylation of the 3'-methyl analogue 4, but less acetylation with the 3'-chloro analogue 5. Distinct expression patterns of N-acetyltransferase NAT1 and NAT2 have been demonstrated in our panel of cell lines.
