ISSN:
0009-2940
Schlagwort(e):
2-Azapropenylium salts, 1,3-dialkoxy- and 1,1,3,3-tetraalkoxy-
;
Enamines of N-methyl-4-piperidone
;
4-Aminopyridines
;
3,7-Diazabicyclo[3.3.1]non-2-en-9-ones
;
Retro-Mannich reaction
;
Chemistry
;
Inorganic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
1,3-Dialkoxy-2-azapropenylium salts 1 react with enamines 2 of N-methyl-4-piperidone at room temperature to give 2,6-disubstituted 4-aminopyridines 4, 5 in low to moderate yield after hydrolysis. Intermediates of the reaction of 1a with 2 are the bicyclic iminium salts 6 and 7, which may be detected 1H-NMR spectroscopically prior to hydrolysis. Hydrolysis of the mixture obtained from the reaction of 1a with 2a under basic conditions furnishes the bicyclic ketone 3 as the major product. A “retro-Mannich”-type reaction is suggested to explain the degradation of the bicyclic intermediates 6, 7 with the formation of the pyridines 4, 5.
Zusätzliches Material:
1 Tab.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/cber.19941270817
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