Benzo [b] thiophene-5, 6-dicarboxaldehyde reacts with dibenzyl ketone, thiodiacetic acid dimethyl ester, hydrazine, p-toluidine, p-aminoacetophenone and nitromethane to give the corresponding seven, six and five-membered rings condensed to benzo [b] thiophene. Reaction of benzo [b] thiophene-5, 6-dicarboxaldehyde with p-toluidine in the presence of 2- mercaptoethanol gives highly fluorescent compounds. Also, benzo [b] thiophene-5, 6- ...
