2-Aryl-N-vinylpyrroles

Arylazo groups of the monomers were assumed to decompose upon heating and generate radicals capable of initiating the polymerization to afford homopolymers. These radicals underwent recombination to yield 2-aryl-N-vinylpyrroles (Scheme 14). 

The yield of 2-aryl-N-vinylpyrroles essentially depends on the substituent in the benzene nucleus. Sharp drop of 4-bromophenyl-N-vinylpyrrole (from 4-bromoace-tophenone oxime) is logical it is caused by bromine saponification with strong base. From 4-nitroacetonenone oxime, the pyrrole is not formed under the conditions studied due to instability of the substituent in superbase medium. When the temperature decreases to 80°C, the reaction of 4-phenoxyacetophenone oxime and acetylene leads to the corresponding pyrrole in 43% yield [221]. 

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