Sulfuric Acid → 2-(4-Fluorophenyl)naphtho[2,3-d]oxazole-4,9-dione

Participants

Reaction Steps

To a solution of 6.22 g (30 mmol) of 2-amino-3-chloro-1,4-dihydro-1,4-dioxo-naphthalene in 60 mL of nitrobenzene, 18.00 mL (150 mmol) of 4-fluorobenzoic acid chloride are added with protection from light. After 10 min of stirring with reflux, 0.20 mL of concentrated sulfuric acid is added. After 12 h and complete cooling, ether is added to obtain a yellow precipitate which is filtered through fritted glass, washed with ether and purified on a flash column (support: silica; conditioning: heptane; eluant: dichloromethane/heptane, 60/40). The yellow powder obtained after evaporation of the solvent is uncolored, recrystallized in dichloromethane to produce 2.90 g of 4,9-dihydro-4,9-dioxo-2-(4-fluorophenyl)-naphtho[2,3-d]oxazole in the form of yellow crystals.

Provenance & Evidence