22190-38-1Relevant articles and documents
Predictable site-selective functionalization: Promoter group assistedpara-halogenation ofN-substituted(hetero)aromatics under metal-free condition
Gupta, Shiv Shankar,Manisha,Kumar, Rakesh,Dhiman, Ankit Kumar,Sharma, Upendra
, p. 9675 - 9687 (2021/12/01)
Herein, regioselectivepara-C-H halogenation ofN-pyrimidyl (hetero)aromatics through SEAr (electrophilic aromatic substitution) type reaction is disclosed. SEAr type reaction has been utilized for the C5-bromination of indolines (para-selective) withN-bromosuccinimide under metal and additive-free conditions in good to excellent yields. The developed methodology is also applicable for iodination and challenging chlorination. The pyrimidyl group is identified as a reactivity tuner that also controls the regioselectivity. The present method is also applicable for selective halogenation of aniline, pyridine, indole, oxindole, pyrazole, tetrahydroquinoline, isoquinoline, and carbazole. DFT studies such as Fukui nucleophilicity and natural charge maps also support the observedp-selectivity. Post-functionalization of the title compound into the corresponding arylated, olefinated, and dihalogenated products is achieved in a one-pot, two-step fashion. Late-stage C-H bromination was also executed on drug/natural molecules (harmine, etoricoxib, clonidine, and chlorzoxazone) to demonstrate the applicability of the developed protocol.
Efficient synthesis process of medical intermediate 5-bromoindole
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, (2020/08/06)
The invention discloses an efficient synthesis process of a medical intermediate 5-bromoindole, comprising the following steps of: using an indole compound as a raw material, carrying out low-pressureliquid-phase hydrogenation to destroy five-membered ring conjugation of indole to obtain an indoline compound; enabling the indoline compound to react with an acylation reagent, and protecting nitrogen, so as to obtain an N-acyl indoline compound; carrying out bromination on the N-acyl indoline compound to obtain a 5-bromo-N-acyl indoline compound; carrying out deacylation protection on the 5-bromo-N-acyl indoline compound to obtain a 5-bromoindoline compound; and carrying out oxidative dehydrogenation on the 5-bromoindoline compound by using oxygen or air under the action of a cuprous catalyst and nitric oxide to obtain the target compound 5-bromoindole. The steps involved in the process are convenient to operate, the conditions are mild, and environmental pollution is reduced; finally,the prepared product is high in yield, high in purity and low in energy consumption.
Cooperativity within the catalyst: alkoxyamide as a catalyst for bromocyclization and bromination of (hetero)aromatics
Mondal, Haripriyo,Sk, Md Raja,Maji, Modhu Sudan
supporting information, p. 11501 - 11504 (2020/10/12)
Alkoxyamide has been reported as a catalyst for the activation ofN-bromosuccinimide to perform bromocyclization and bromination of a wide range of substrates in a lipophilic solvent, where adequate suppression of the background reactions was observed. The key feature of the active site is the alkoxy group attached to the sulfonamide moiety, which facilitates the acceptance as well as the delivery of bromonium species from the bromine source to the substrates.
