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A New Cyclization Involving the Diazonium and ortho ‐( tert ‐Butyl)‐ NNO ‐azoxy Groups − Synthesis of 1,2,3,4‐Benzotetrazine 1‐Oxides
Author(s) -
Lipilin Dmitry L.,
Smirnov Oleg Yu.,
Churakov Aleksandr M.,
Strelenko Yuri A.,
Ioffe Sema L.,
Tartakovsky Vladimir A.
Publication year - 2002
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/1099-0690(200210)2002:20<3435::aid-ejoc3435>3.0.co;2-z
Subject(s) - chemistry , azoxy , tetrazine , medicinal chemistry , nucleophile , bromine , ring (chemistry) , decomposition , intramolecular force , thermal decomposition , stereochemistry , organic chemistry , catalysis
The synthesis of 1,2,3,4‐benzotetrazine 1‐oxides (BTOs) is described. Bromo‐BTOs 4b−d were prepared by the intramolecular cyclization of diazonium salts bearing an ortho ‐( tert ‐butyl)‐ NNO ‐azoxy group. BTOs bearing electron‐releasing substituents were obtained by nucleophilic displacements of bromine in 4b−d . The formation of the BTO cyclic system involves the intermediate 2‐( tert ‐butyl)‐1,2,3,4‐benzotetrazinium 4‐oxides, which arise from an N , N ‐[1,2]‐shift of the tert ‐butyl group. Decomposition of BTOs involves opening of the tetrazine ring to afford ortho ‐azidonitroso derivatives, followed by their cyclization with the evolution of the N 2 molecule to give benzofurazans. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)