Efficient synthesis and spectroscopic analysis of 8-nitro spiro C-3-annulated 2-benzazepines and their N-oxides

Nitroderivatives 9a-g have been prepared with great C-8 regioselectivity by allowing the corresponding 1,2,4,5-tetrahydrospiro[3H-2-benzazepine-3,1′-cycloalkanes] 8a-g to react with potassium nitrate and concentrated H2SO4. The oxidative reaction of a nitrogen-carbon bond in spirobenzazepines 8 and 9 was performed with H2O2 and catalytic amounts of sodium tungstate at room temperature affording nitrones 10a-d in moderate to high yields. Stereochemical assignments for all the 2-benzazepine derivatives obtained were derived from a full analysis of the 1H NMR spectroscopic data and an X-ray crystallographic analysis of 1,5dimethyl-8-nitro-1,2,4,5-tetrahydrospiro[3H-2-benzazepine-3, 1′-cyclohexane] 9c. These data indicate that the 2-benzazepines 8-11 in solution present the azepine ring preferably in the chair conformation, with the methyl substituent at C-5 disposed equatorially.

Authors
Varlamov A. 1 , Kouznetsov V.2 , Zubkov F. 1 , Chernyshev A. 1 , Alexandrov G. 1 , Palma A.2 , Vargas L.2 , Salas S.2
Editors
-
Journal
Publisher
-
Number of issue
6
Language
English
Pages
849-854
Status
Published
Department
-
DOI
-
Number
-
Volume
-
Year
2001
Organizations
  • 1 Department of Organic Chemistry, Russ. Peoples Friendship University, Moscow 117923, Russian Federation
  • 2 Laboratory Fine Organic Synthesis, School of Chemistry, Industrial University of Santander, A.A. 678, Bucaramanga, Colombia
Keywords
2-Benzazepines; Homoallylamines; Nitrones; Regioselective nitration
Date of creation
19.10.2018
Date of change
19.10.2018
Short link
https://repository.rudn.ru/en/records/article/record/366/