Preparation of new nitrogen-bridged heterocycles. 55. Reinvestigation of the bromination/dehydrobromination of ethyl 3-[2-(methylthio)indolizin-3-yl]acrylate derivatives.
The bromination/dehydrobromination reactions of ethyl 3-[1-alkoxycarbonyl-2-(methylthio)indolizin-3-yl]acrylates were reinvestigated. Reactions of the title compounds with two equivalents of bromine, followed by heating of the resulting reaction mixture and then treatment with a base gave the unexpected dialkyl 7-bromothieno[2,3-b]indolizine-2,9-dicarboxylates, while similar reactions using benzyltrimethylammonium tribromide as a brominating agent afforded only non-brominated thieno[2,3-b]indolizine derivatives, which were converted to the corresponding 7-bromo derivatives upon further treatment with bromine.
Kakehi
Akikazu
A
Department of Chemistry and Material Engineering, Faculty of Engineering, Shinshu University, Tokyo, Japan. akakehi@gipwc.shinshu-u.ac.jp
Ito
Suketaka
S
Suga
Hiroyuki
H
Kobayashi
Yuhichi
Y
Zuo
Peng
P
Iriye
Ryozo
R
D001952:Bridged-Ring Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D003461:Crystallography; D006571:Heterocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D007212:Indolizines / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*
D001952:Bridged-Ring Compounds; D006571:Heterocyclic Compounds; D007212:Indolizines; D000644:Quaternary Ammonium Compounds; C000168:benzyltrimethylammonium; D009584:Nitrogen