Sulfuric Acid → Benzo(b)thiophene-3(2H)-one 1,1-dioxide

Participants

Reaction Steps

A suspension of Compound X (130.0 g, 0.51 mol) in 350 ml of 10% aqueous H2SO4 was heated at reflux for 6 h (until gas evolution ceased). The reaction mixture was cooled and a white solid precipitated, which was collected by filtration and washed in cold water (30 ml). The product was recrystallized from ethanol to give 83.8 g (90%) of Compound Y as a white crystalline solid:melting point 133°-134° C.

Provenance & Evidence