60418-14-6Relevant academic research and scientific papers
Copper-Catalyzed Chelation-Assisted ortho-Nitration of 2-Aryls Using Pharmacophoric Benzothiazoles and Benzoxazoles as Directing Groups
Vinayak, Botla,Ashok, Akudari,Chandrasekharam, Malapaka
, p. 7127 - 7132 (2017)
A copper-catalyzed chelation-assisted ortho-nitration reaction of aryl derivtives has been achieved, using benzazoles as efficient directing groups. The reaction is general and efficient for aryl derivatives with various electronic properties, and also with different pharmacophorically important directing groups, i.e., benzoxazoles, benzothiazoles, and benzimidazoles. The nitro-group-containing products have significance as fluorogenic compounds and potential nitroreductase substrates that could be used for the detection of clinically important microorganisms. The nitration reaction proceeds with an inexpensive copper catalyst and a mild, cheap, and environmentally friendly nitro source, Fe(NO3)3·9H2O. This operationally simple and functional-group-tolerant protocol for the nitration of 2-aryl benzazoles proceeds with a high regioselectivity without the exclusion of air or moisture.
Copper mediated decarboxylative direct C-H arylation of heteroarenes with benzoic acids
Patra, Tuhin,Nandi, Sudip,Sahoo, Santosh K.,Maiti, Debabrata
supporting information, p. 1432 - 1435 (2016/01/25)
Decarboxylative coupling reactions to date require a stoichiometric oxidant (such as copper and silver salts) for decarboxylation purposes along with a metal catalyst (e.g. palladium) for cross-coupling. In this communication, an economic and sustainable approach by using a simple copper salt was developed in the presence of molecular oxygen as the sole oxidant. A wide range of 5-membered heteroarenes undergo aryl-heteroaryl cross-coupling with electron deficient aryl carboxylic acids.
Palladium-catalyzed ortho-nitration of 2-arylbenzoxazoles
Qiao, Hui-Jie,Yang, Fan,Wang, Shi-Wei,Leng, Yu-Ting,Wu, Yang-Jie
, p. 9258 - 9263 (2015/11/27)
An efficient and general protocol for palladium-catalyzed chelation-assisted ortho-nitration of 2-arylbenzoxazoles has been developed. This nitration exhibits high regioselectivity for the substrates, and the reaction could tolerate many functional groups such as F, Cl, Br, CH3, CH3O, affording ortho-nitration products in moderate to good yields. Moreover, some 2-arylbenzoxazole heterocyclic analogues proceed well under this catalytic system. Further studies have been performed to obtain insight into the mechanism.
2-Arylbenzothiazole, benzoxazole and benzimidazole derivatives as fluorogenic substrates for the detection of nitroreductase and aminopeptidase activity in clinically important bacteria
Cellier, Marie,Fabrega, Olivier J.,Fazackerley, Elizabeth,James, Arthur L.,Orenga, Sylvain,Perry, John D.,Salwatura, Vindhya L.,Stanforth, Stephen P.
experimental part, p. 2903 - 2910 (2011/06/21)
A series of 2-(2-nitrophenyl)benzothiazole 7, 2-(2-nitrophenyl)benzoxazole 10 and 2-(2-nitrophenyl)benzimidazole 13 derivatives have been synthesised and assessed as indicators of nitroreductase activity across a range of clinically important Gram negativ
A Keggin heteropoly acid as an efficient catalyst for an expeditious, one-pot synthesis of 1-methyl-2-(hetero)arylbenzimidazoles
Chakrabarty, Manas,Mukherji, Ajanta,Mukherjee, Ratna,Arima, Shiho,Harigaya, Yoshihiro
, p. 5239 - 5242 (2008/02/08)
The Keggin heteropoly acid, silicotungstic acid, H4SiW12O40, has been demonstrated to be highly efficient for an expeditious, one-pot synthesis of 1-methyl-2-(hetero)arylbenzimidazoles from N-methyl-1,2-phenylenediamine and (hetero)aryl aldehydes in ethyl acetate at room temperature. The catalyst works equally well for N-phenyl-1,2-phenylenediamine.
Intermolecular SNAr of the heterocycle-activated nitro and fluoro groups-application in the synthesis of polyazamacrocyclic ligands
-
Page/Page column 29, (2010/02/14)
A new class of tetracylic benzimidazole compounds and derivatives thereof. Additionally provided is a synthetic route for the generation of these and related compounds via Intramolecular Aromatic Nucleophilic Substitution (SNAr) of the Benzimid
Synthesis and crystallographic characterization of some derivatives of benzimidazole
Das, T. Mohan,Rao, Chebrolu P.,Kalle, Nattinen,Rissanen, Kari
, p. 661 - 665 (2007/10/03)
Three derivatives of benzimidazole have been synthesized and characterized based on 1H and 13C NMR, FTIR, FAB-mass and UV spectra, and the structures of two compounds are characterized based on single crystal XRD studies. Existence of both interand intra-molecular hydrogen bonds has been identified in the case of 2-(o-aminophenyl)benzimidazole amine and not in case of N-methyl-2-(o-nitrophenyl)benzimidazole. While the former is a completely planar molecule, the latter is not. Both the compounds exhibit interesting lattice structures.
Intramolecular Aromatic Nucleophilic Substitution of the Benzimidazole-Activated Nitro Group
Fekner, Tomasz,Gallucci, Judith,Chan, Michael K.
, p. 4795 - 4798 (2007/10/03)
(Equation Presented) A wide range of 2-(2-nitrophenyl)-1H-benzimidazoles undergo high-yielding intramolecular SNAr of nitrite with N-pendant alkoxides under mild conditions (DMF, rt). When this operationally simple process is carried out at ele
In Situ Generation and Synthetic Application of 2-Phenylbenzimidazoline to the Selective Reduction of Carbon-Carbon Double Bonds of Electron-Deficient Olefins
Chikashita, Hidenori,Nishida, Shuichi,Miyazaki, Makoto,Morita, Yasuhiro,Itoh, Kazuyoshi
, p. 737 - 746 (2007/10/02)
2-Phenylbenzimidazoline (PBI) as a mild, selective, and convenient reducing agent was efficiently generated in situ from o-phenylenediamine and benzaldehyde in alcohols.A generally applicable method for the selective reduction of carbon-carbon double bonds of a variety of electron-deficient olefins with an alcoholic solution of PBI is described.The reduction of α,β-unsaturated ketones to the corresponding saturated ketones could also be accomplished (but, less effectively) with PBI with the aid of a Lewis-acid catalyst. 1-Methyl-2-(o-nitrophenyl)benzimidazoline prepared and isolated by the reaction of o-nitrobenzaldehyde with N-methyl-o-phenylenediamine reduced benzylidenemalononitrile to give benzylmalononitrile and 1-methyl-2-(o-nitrophenyl)benzimidazoline in high yields.This shows the validity of PBI to be the actual reducing species in the present reduction system.From a mechanistic study, the present reductions could be interpreted in terms of a mechanism involving a synchronous transport of a pair of hydrogens or a sequential transfer of a hydride and a proton from PBI to the olefins.
Competitive Cyclisations of Singlet and Triplet Nitrenes. Part 9. 2-(2-Nitrophenyl)-benzothiazoles and -benzimidazoles
Hawkins, David,Lindley, John M.,McRobbie, Ian M.,Meth-Cohn, Otto
, p. 2387 - 2391 (2007/10/02)
2-(2-Nitrophenyl)benzothiazole, produced by deoxygenation of the corresponding nitro-compound or by thermolysis or photolysis of the related azide, gives indazolobenzothiazole by attack on the benzothiazole nitrogen.Similar attack of the nitrene in 2-(2-nitrophenyl)benzimidazoles gives benzimidazoindazoles in good yield.However, with an appropriate 1-substituent in the benzimidazole (e.g.Me or CHMe2) the nitrene in its triplet state (generated by acetophenone-sensitised photolysis or by thermolysis of the azide bearing a 4-dimethylamino-group) preferentially attacks this substituent giving benzimidazoquinazolines.
