Sulfuric Acid → 4,9-Dihydro-4,9-dioxo-2-(2-fluorophenyl)-naphtho[2,3-d]oxazole

Participants

Reaction Conditions

Reaction Steps

To a solution of 6.0 g (28.8 mmol) of 2-amino-3-chloro-1,4-dihydro-1,4-dioxonaphthalene in 120 mL of nitrobenzene, 17.10 mL (144.0 mmol) of 2-fluorobenzoic acid chloride are added with protection from light. After 10 min of stirring at 80° C., 0.20 mL of concentrated sulfuric acid is added. The reaction mixture is heated to reflux for 18 h. After complete cooling, ether is added to produce a yellow precipitate, which is filtered through fritted glass and washed with ether. This solid is then purified on a flash column (support: silica; conditioning: heptane; eluant: dichloromethane/heptane, 60/40) to produce 2.5 g of 4,9-dihydro-4,9-dioxo-2-(2-fluorophenyl)-naphtho[2,3-d]oxazole in the form of yellow crystals.

Provenance & Evidence