Sulfuric Acid → HCID 15461582, compound

Participants

Reaction Steps

To a solution of 5.0 g (24 mmol) of 2-amino-3-chloro-1,4-dihydro-1,4-dioxonaphthalene in 60 mL of dioxane, one adds at ambient temperature 15.3 mL (120 mmol) of 4-chlorobenzoic acid chloride and 0.5 mL of concentrated sulfuric acid. The reaction mixture is heated to reflux for 4 h, then evaporated to dryness, redissolved in 200 mL of dichloromethane, and neutralized at cold temperature with 100 mL of 10N sodium hydroxide. The organic phase is then washed three times with water and dried over calcium chloride. The red powder so obtained is purified on a flash column (support: silica; conditioning: heptane; eluant: dichloromethane/heptane, 70/30). The yellow crystals obtained after evaporation of the solvent are uncolored and recrystallized in dichloromethane to produce 2.5 g of 2-(4-chlorophenyl)-4,9-dihydro-4,9-dioxo-naphtho[2,3-d]oxazole in the form of yellow crystals.

Provenance & Evidence