ISSN:
1573-8353
Schlagwort(e):
alkenylazomethines
;
benzylideneanilines
;
dihydroquinolines
;
N-(4-nitrobenzylidene)-2-alkenylaniline
;
N-(4-nitrobenzylidene)-2-cyclopropylaniline
;
phenylcyclopropanes
;
quinolines
;
cyclopropanes
;
2-cyclopropylanilines
;
intramolecular rearrangements
;
acid-catalyzed rearrangements
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
Abstract The acid-catalyzed conversions of N-(4-nitrobenzylidene)-2-cyclopropyl- and N-(4-nitrobenzylidene)-2-alkenylanilines have been studied. It has been established that the protonated azomethine unit of N-(4-nitrobenzylidene)-2-cyclopropylanilines is not capable of initiating intramolecular heterocyclization with participation of the three-membered ring. Conversion of N-(4-nitrobenzylidene)-2-(1-methylcyclopropyl)aniline to derivatives of quinoline is possible under the influence of concentrated H2SO4. Under the same conditions 2-methylcyclopropyl- and cyclopropyl-substituted Schiff's bases form only the corresponding alkenylazomethines (isomerization of the three-membered ring). Under the influence of more moderate acids (trifluoroacetic, polyphosphoric) N-(4-nitrobenzylidene)-2-propenyl- and N-(4-nitrobenzylidene)-2-buten-2-yl)anilines are converted to the corresponding dihydroquinolines and quinolines in high yields. N-(4-Nitrobenzylide! ne)- 2-(2,2-dimethylvinyl)aniline does not form derivatives of quinoline under the influence of the same acids in the given conditions.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1002824917758
Permalink
