Selenophens Fused to Five-membered Rings

Selenophens Fused to Five-membered Rings.—Reaction of 3-(3-selenienyl)-acrylic acid with thionyl chloride and pyridine gives a complex mixture of 

Mantovani, P. Faller, L. Christiaens, and M. Renson, Bull. Soc. chim. France, 

Decarboxylation of the acids gave the parent compounds (541) and (542). The product of condensation between o-(methylseleno)phenylacetic acid and o-methylthio- or o-methylseleno-benzaldehydes (549) gave the tetracyclic derivatives (550). These were also obtained by Rieche formylation of (551). The pyrrole-fused selenophen (552) was prepared similarly to the 

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