589-17-3Relevant academic research and scientific papers
Continuous Synthesis and Separation ofp-Bromobenzyl Bromide Using Atom-Efficient Bromination ofp-Bromotoluene without Any Organic Effluent: Potential for Green Industrial Practice
Sancheti, Sonam V.,Yadav, Ganapati D.
, p. 2071 - 2080 (2021/09/13)
This work focuses on the bromination ofp-bromotoluene (PBT) using different brominating agents such as liquid Br2, NaBr-NaBrO3, NaBr-NaBrO3-NaCl, NaBr-H2O2, and HBr-H2O2. NaBr-NaBrO3-NaCl is an eco-friendly brominating agent obtained from a bromine recovery plant. Both NaBr-NaBrO3and NaBr-NaBrO3-NaCl were found to be nonhazardous and efficient brominating agents. Pure NaBr-NaBrO3resulted in the best PBT conversion with 79.7% Br atom efficiency in water and 98.2% average Br atom efficiency using dichloroethane as a solvent. Dichloroethane is de facto no longer used in the US and Europe and is not eco-friendly; the process with water as a solvent is the best. The substrate to active bromine molar ratio of 3:1 was found to be sufficient to get the maximum selectivity ofp-bromobenzyl bromide (PBBB). The low-temperature crystallization method was used for separation cum purification of the product. Unreacted PBT was recycled along with the dibromo byproduct obtained. The dibromo product, which was built up gradually in the reaction mixture over 10 successive batches, was converted back into PBBB/PBT through NaBH4treatment of the mother liquor. This continuous process is highly sustainable and produces zero organic waste, making it potentially attractive toward green industrial implementation.
PYRROLIDINE GLYCOSIDASE INHIBITORS
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Page/Page column 130, (2020/03/15)
Compounds of formula (I) wherein A, W, R3b, Z and p have the meaning according to the claims can be employed, inter alia, for the treatment of tauopathies and Alzheimer's disease.
N -Hydroxyphthalimide/benzoquinone-catalyzed chlorination of hydrocarbon C-H bond using N -chlorosuccinimide
Li, Zi-Hao,Fiser, Béla,Jiang, Biao-Lin,Li, Jian-Wei,Xu, Bao-Hua,Zhang, Suo-Jiang
supporting information, p. 3403 - 3408 (2019/04/01)
The direct chlorination of C-H bonds has received considerable attention in recent years. In this work, a metal-free protocol for hydrocarbon C-H bond chlorination with commercially available N-chlorosuccinimide (NCS) catalyzed by N-hydroxyphthalimide (NHPI) with 2,3-dicyano-5,6-dichlorobenzoquinone (DDQ) functioning as an external radical initiator is presented. Aliphatic and benzylic substituents and also heteroaromatic ones were found to be well tolerated. Both the experiments and theoretical analysis indicate that the reaction goes through a process wherein NHPI functions as a catalyst rather than as an initiator. On the other hand, the hydrogen abstraction of the C-H bond conducted by a PINO species rather than the highly reactive N-centered radicals rationalizes the high chemoselectivity of the monochlorination obtained by this protocol as the latter is reactive towards the C(sp3)-H bonds of the monochlorides. The present results could hold promise for further development of a nitroxy-radical system for the highly selective functionalization of the aliphatic and benzylic hydrocarbon C-H.
NMP-mediated chlorination of aliphatic alcohols with aryl sulfonyl chloride for the synthesis of alkyl chlorides
Zheng, Dagui,Mao, Liu-Liang,Zhu, Xian-Hong,Zhou, An-Xi
supporting information, p. 2793 - 2800 (2018/11/06)
NMP-mediated chlorination of aliphatic alcohols has been developed for the synthesis of alkyl chlorides. This facile, efficient and practical approach used simple and readily available aryl sulfonyl chlorides as the chlorination reagent for the construction of C–Cl bond in good to excellent yields with mild conditions and broad substrate scope.
Halogenation through Deoxygenation of Alcohols and Aldehydes
Chen, Jia,Lin, Jin-Hong,Xiao, Ji-Chang
supporting information, p. 3061 - 3064 (2018/05/28)
An efficient reagent system, Ph3P/XCH2CH2X (X = Cl, Br, or I), was very effective for the deoxygenative halogenation (including fluorination) of alcohols (including tertiary alcohols) and aldehydes. The easily available 1,2-dihaloethanes were used as key reagents and halogen sources. The use of (EtO)3P instead of Ph3P could also realize deoxy-halogenation, allowing for a convenient purification process, as the byproduct (EtO)3Pa?O could be removed by aqueous washing. The mild reaction conditions, wide substrate scope, and wide availability of 1,2-dihaloethanes make this protocol attractive for the synthesis of halogenated compounds.
NOVEL DIHYDROPYRIDINONE AND DIHYDROPYRIMIDINONE COMPOUNDS AND THEIR USE
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Page/Page column 61, (2017/12/27)
The present invention is directed to novel compounds of Formula I; pharmaceutically acceptable salts or solvates thereof, and their use.
SNAr catalysis enhanced by an aromatic donor-acceptor interaction; Facile access to chlorinated polyfluoroarenes
Senaweera, Sameera,Weaver, Jimmie D.
supporting information, p. 7545 - 7548 (2017/07/12)
Selective catalytic SNAr reaction of polyfluoroaryl C-F bonds with chloride is shown. Stoichiometric TMSCl makes the reaction exergonic and allows catalysis, which involves ground state elevation of chloride, aromatic donor-acceptor interactions, and stabilization of the Meisenheimer complex. Traditional cross-coupling of the products is now possible and demonstrates the utility.
EPIDITHIODIKETOPIPERAZINE COMPOUNDS, COMPOSITIONS, AND METHODS
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Paragraph 0193, (2015/07/07)
Epidithiodiketopiperazine compounds, pharmaceutical compositions based thereon and methods of their synthesis, as part of treating, inhibiting and reducing transcription and translation of hypoxia inducible genes are described. In another aspect, the present disclosure describes a method for interfering with hypoxia-induced transcriptional pathway in a cell comprising: contacting the cell with at least one compound disclosed herein. In another aspect, the present disclosure describes a method for treating breast cancer, a solid cancer, a blood cancer, a subject suffering from carcinoma in need of said treatment, and renal cell carcinoma (RCC), comprising: administering to the subject an effective amount of at least one compound disclosed herein. In some embodiments of the methods described herein, the method further comprises administering an additional anti-cancer and/or cytotoxic agent.
Rasta resin-triphenylphosphine oxides and their use as recyclable heterogeneous reagent precursors in halogenation reactions
Xia, Xuanshu,Toy, Patrick H.
supporting information, p. 1397 - 1405 (2014/07/22)
Heterogeneous polymer-supported triphenylphosphine oxides based on the rasta resin architecture have been synthesized, and applied as reagent precursors in a wide range of halogenation reactions. The rasta resin-triphenylphosphine oxides were reacted with either oxalyl chloride or oxalyl bromide to form the corresponding halophosphonium salts, and these in turn were reacted with alcohols, aldehydes, aziridines and epoxides to form halogenated products in high yields after simple purification. The polymersupported triphenylphosphine oxides formed as a byproduct during these reactions could be recovered and reused numerous times with no appreciable decrease in reactivity.
Sulfite formation versus chlorination of benzyl alcohols with thionyl chloride
Rodriguez, Deana A.,Priefer, Ronny
, p. 3045 - 3048 (2014/05/20)
Recently, we have reported the photolytic decay of a library of para-substituted dibenzylic sulfites in a Srinivasan-Griffin-Rayonet photochemical reactor. In an attempt to synthesize the complete library for that study we discovered that bis(p-methoxybenzyl) sulfite and bis(p-phenoxybenzyl) sulfite could not be formed and only their corresponding benzyl chlorides were synthesized. Thus, sulfite formation versus chlorination of a range of para-substituted benzyl alcohols with thionyl chloride was investigated. Sulfite formation was observed to be parabolically related to Swain and Lupton's Field ?-values while chloride formation was found to be linearly related to Swain and Lupton's Field ?-values.
