Synthesis and reactivity of 5-and 6-hydroxy-benzo[b]furan-2-selenolates

Treatment of 2,4-and 2,5-diacetoxyacetophenone semicarbazones with selenium dioxide gave 4-(2,4-and 2,5-diacetoxyphenyl)-1,2,3-selenadiazoles which were readily deacylated by the action of hydrochloric acid. 4-(2,4-and 2,5-Dihydroxyphenyl)-1,2,3-selenadiazoles thus obtained underwent decomposition in the presence of potassium carbonate in acetonitrile with formation of 5-and 6-hydroxybenzob]furan-2-selenolates which were subjected to alkylation.