Structural studies of C-ring substituted unnatural analogues of prodigiosin

Abstract

The structure of both the free base and the hydrochloride of an unnatural analogue of prodigiosin, 4-methoxy-5-((4,5-dimethyl -2H-pyrrol-2-ylidene)methyl)- 2,2′-bi-1H-pyrrole, are reported. The free base crystallizes from methylene chloride as a hydrogen bonded dimer. The structure of the hemihydrate hydrochloride of the related 4-methoxy-5-((1-methyl -2H-pyrrol-2-ylidene)methyl)- 2,2′-bi-1H-pyrrole is also reported.