Compounds (la-f) can be used as starting materials for the preparation of indolizines. Indolizines with substituents in the pyridine ring have received little attention; the corresponding nitro-compounds are known [3], and in the last decade the ethoxycarbonyl derivatives have been examined in detail [5]. It has been found that 8- ethoxycarbonylindollzines are not converted into amides when their solutions are kept ...
