Pyrrole → 2-Phthalidyl-pyrole

Participants

Reaction Steps

Rees et al. in further studies, ibid., pp. 687-91 (1965), reported that the condensation of phthalaldehydic acid could be extended to pyrroles and found that phthalaldehydic acid reacted with pyrrole and 2,5-dimethyl pyrrole in boiling benzene in the absence of an external catalyst to give high yields of 2-phthalidyl-pyrrole and 3-phthalidyl-pyrrole, respectively. In these reactions, it was observed that pyrrole tended to substitute in the 2-position when possible to yield the 2-phthalidyl derivative. In a further extension of the reactions, the authors found that naphthalaldehydic acid, though less reactive than phthalaldehydic acid, behaved in a similar manner and could be condensed with indole under fusion conditions to yield 3-naphthalidylindole.

Provenance & Evidence