Fischer indole cyclization and electron impact studies of ethyl pyruvate 2-chloro-6-methylphenylhydrazone.

Polyphosphoric acid-catalyzed indolization of the title compd. (I) yielded II, which indicates that 1,2-migration of the Me group is preferred over 1,3-halogen migration. The mass spectral fragmentation patterns of I and 2 isomers are discussed. [on SciFinder(R)]