Pyrroles side-chain bromination

Bromination of appropriate 5-acetoxymethyl pyrrole-2-carboxylic acids in ethanol-free chloroform at 10° affords previously inaccessible 5-bromo-5 -bromomethylpyrromethanes with alternating acetic acid (or methyl) and propionic acid side chains useful for copro- and uroporphyrin syntheses. 

Pyrrole has been chemically polymerized with oxidants including sulfuric acid [87], bromine and iodine [88], copper(II) perchlorate [89], and iron(III) chloride [90]. Soluble polypyrrole can be prepared by the introduction of flexible side chains [91-93]. In contrast with the progress made in the synthesis of regioregular PTs, all 3-substituted polypyrroles reported so far have a regio-random structure. 

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