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.
, 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.
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.