136-85-6Relevant articles and documents
Microwave-assisted solid phase diazotation: A method for the environmentally benign synthesis of benzotriazoles
Kokel, Anne,T?r?k, Béla
, p. 2515 - 2519 (2017)
A novel environmentally benign approach based on microwave-assisted solid phase diazotation to convert o-phenylendiamines to substituted benzotriazoles is described. Excellent yields were obtained for a phenylenediamines proving the efficacy of the method. The reaction was carried out in the solid phase under microwave irradiation taking advantage of the strong microwave absorption capability of K-10 montmorillonite that acted as a catalyst and medium in one. The catalyst is recyclable, and the reaction occurs with high efficiency and does not produce any harmful waste.
Making endo-cyclizations favorable again: A conceptually new synthetic approach to benzotriazoles via azide group directed lithiation/cyclization of 2-azidoaryl bromides
Ageshina, Alexandra A.,Chesnokov, Gleb A.,Topchiy, Maxim A.,Alabugin, Igor V.,Nechaev, Mikhail S.,Asachenko, Andrey F.
supporting information, p. 4523 - 4534 (2019/05/17)
Although benzotriazoles are important and ubiquitous, currently there is only one conceptual approach to their synthesis: bridging the two ortho-amino groups with an electrophilic nitrogen atom. Herein, we disclose a new practical alternative-the endo-cyclization of 2-azidoaryl lithiums obtained in situ from 2-azido-aryl bromides. The scope of the reaction is illustrated using twenty-four examples with a variety of alkyl, alkoxy, perfluoroalkyl, and halogen substituents. We found that the directing effect of the azide group allows selective metal-halogen exchange in aryl azides containing several bromine atoms. Furthermore, (2-bromophenyl)diazomethane undergoes similar cyclization to give an indazole. Thus, cyclizations of aryl lithiums containing an ortho-X = Y = Z group emerge as a new general approach for the synthesis of aromatic heterocycles. DFT computations suggested that the observed endo-selectivity applies to the anionic cyclizations of other functionalities that undergo "1,1-additions" (i.e., azides, diazo compounds, and isonitriles). In contrast, cyclizations with the heteroatomic functionalities that follow the "1,2-addition" pattern (cyanates, thiocyanates, isocyanates, isothiocyanates, and nitriles) prefer the exo-cyclization path. Hence, such reactions expand the current understanding of stereoelectronic factors in anionic cyclizations.
Synthesis of Structurally Diverse Benzotriazoles via Rapid Diazotization and Intramolecular Cyclization of 1,2-Aryldiamines
Faggyas, Réka J.,Sloan, Nikki L.,Buijs, Ned,Sutherland, Andrew
, p. 5344 - 5353 (2019/05/21)
An operationally simple method has been developed for the preparation of N-unsubstituted benzotriazoles by diazotization and intramolecular cyclization of a wide range of 1,2-aryldiamines under mild conditions, using a polymer-supported nitrite reagent and p-tosic acid. The functional group tolerance of this approach was further demonstrated with effective activation and cyclization of N-alkyl, -aryl, and -acyl ortho-aminoanilines leading to the synthesis of N1-substituted benzotriazoles. The synthetic utility of this one-pot heterocyclization process was exemplified with the preparation of a number of biologically and medicinally important benzotriazole scaffolds, including an α-amino acid analogue.
Selective Synthesis of N-H and N-Aryl Benzotriazoles by the [3 + 2] Annulation of Sodium Azide with Arynes
Guin, Avishek,Gaykar, Rahul N.,Bhattacharjee, Subrata,Biju, Akkattu T.
, p. 12692 - 12699 (2019/10/11)
The synthetic utility of NaN3 as the azide component in the [3 + 2] annulation with arynes generated from 2-(trimethylsilyl)aryltriflates resulting in the transition-metal-free synthesis of N-H and N-aryl benzotriazoles has been demonstrated. Using CsF as the fluoride source in CH3CN, the N-H benzotriazoles are formed in high selectivity instead of the expected azidobenzene. Interestingly, N-aryl benzotriazoles are formed using KF and THF as solvent in an open-flask reaction. Moreover, a method for the N1-arylation of benzotriazole is also presented.
Tert -Butyl nitrite mediated nitrogen transfer reactions: Synthesis of benzotriazoles and azides at room temperature
Azeez, Sadaf,Chaudhary, Priyanka,Sureshbabu, Popuri,Sabiah, Shahulhameed,Kandasamy, Jeyakumar
supporting information, p. 6902 - 6907 (2018/10/02)
A conversion of o-phenylenediamines into benzotriazoles was achieved at room temperature using tert-butyl nitrite. The optimized conditions are also well suited for the transformation of sulfonyl and acyl hydrazines into corresponding azides. This protocol does not require any catalyst or acidic medium. The desired products were obtained in excellent yields in a short span of time.
Molybdenum-Catalyzed Deoxygenation of Heteroaromatic N-Oxides and Hydroxides using Pinacol as Reducing Agent
Rubio-Presa, Rubén,Fernández-Rodríguez, Manuel A.,Pedrosa, María R.,Arnáiz, Francisco J.,Sanz, Roberto
supporting information, p. 1752 - 1757 (2017/05/22)
A molybdenum-catalyzed deoxygenation of pyridine N-oxides and N-hydroxybenzotriazoles, as well as other azole N-oxides, has been developed using pinacol as an environmentally friendly oxo-acceptor. The only by-products are acetone and water making the process a convenient alternative to established protocols in terms of waste generation. The reaction is highly chemoselective and a variety of functional groups are tolerated. The processes are usually very clean allowing the isolation of the pure deoxygenated products after a simple extraction in most cases. (Figure presented.).
Facile synthesis of benzotriazole derivatives using nanoparticles of organosilane-based nitrite ionic liquid immobilized on silica and two room-temperature nitrite ionic liquids
Valizadeh, Hassan,Gholipour, Hamid,Mahmoodian, Manzar
, p. 2801 - 2808 (2013/08/15)
Nanoparticles of organosilane-based nitrite ionic liquid immobilized on silica, 1-butyl-3-methylimidazolium nitrite, and 1-(3-trimethoxysilylpropyl)-3- methylimidazolium nitrite were used as effective reagents for the preparation of benzotriazole derivatives from 1,2-diaminobenzenes at room temperature under mild solvent-free conditions. These ionic liquids play as nitrosonium sources in this procedure.1,2-Diaminobenzene derivatives have been treated with ionic liquids to give the related diaminobenzenes in very good to excellent yields in short reaction times. Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the full experimental and spectral details.
A New Deprotection Method for Levulinyl Protecting Groups under Neutral Conditions
Ono, Mitsunori,Itoh, Isamu
, p. 585 - 588 (2007/10/02)
Sulfit ion-induced cleavage of the levulinyl group under neutral conditions provides a convenient and mild deprotection method especially for alkali labile and/or oxygen sensitive compounds.