
%0 Journal Article
%A Clezy, PS 
%A Liepa, AJ 
%A Webb, NW 
%T The chemistry of pyrrolic compounds. XX. Bilenes-b as intermediates in the synthesis of porphyrins related to protoporphyrin IX. <I>meso</I>-Pyrrolylporphyrins
%J Australian Journal of Chemistry
%D 1972/09/01
%V 25
%N 9
%P 1991-2001
%K 
%R https://doi.org/10.1071/CH9721991
%U https://www.publish.csiro.au/paper/CH9721991 
%X &#945;-Formyl-&#945;'-methyldipyrrylmethanes have been shown to react with &#945;,&#945;'-   dicarboxydipyrrylmethanes to give hexapyrrenes which cyclize with copper acetate in pyridine to yield meso-pyrrolylporphyrins. However, if an &#945;,&#945;'-dicarboxydipyrrylmethane is decarboxylated in N,N-dimethylformamide and the product converted into its monoimmonium salt (Vilsmeier-Haack intermediate) with benzoyl chloride this salt with an &#945;-formyl-&#945;'-methyldipyrrylrnethane affords a bilene-b which with copper acetate-pyridine gives a normal porphyrin. This latter procedure has been adapted to prepare tetrapyrroles of the protoporphyrin IX type. A synthesis of pemptoporphyrin dimethyl ester is reported. 
