Sulfuric Acid → HCID 15345815, 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 80 mL of dichloromethane, one adds, with protection from light and at ambient temperature, 16 mL (120 mmol) of 4-methoxybenzoic acid chloride, then 0.003 mL of concentrated sulfuric acid. After 3 h of reflux, the reaction mixture is evaporated to dryness; the black oily residue obtained is redissolved in 300 mL of dichloromethane, washed with a solution of 10N sodium hydroxide, then with water, and finally dried over calcium chloride. The product is then purified on a flash column (support: silica 6-35 mm; conditioning: heptane; eluant: dichloromethane/heptane, 60/40), to produce 4.1 g of 4,9-dihydro-4,9-dioxo-2-(4-methoxyphenyl)-naphtho[2,3-d]oxazole in the form of yellow-orangish crystals after recrystallization and color removal with animal charcoal.

Provenance & Evidence