2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → HCID 86691487, compound

Participants

Reaction Conditions

Reaction Steps

In an inert argon atmosphere 17 (4.93 g, 12.7 mmol, 1 eq) was dissolved in abs. 1,4-dioxane (300 mL, dried over sodium) under vigorously stirring at 80° C. 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ, 17.25 g, 76 mmol, 6 eq) was added in portions over a 5 minutes period and the DDQ-vessel was flushed with abs. dioxane (20 mL). The almost black mixture was stirred at 80° C. for two days maintaining the inert atmosphere. After cooling to room temperature the reaction mixture was carefully added to 500 mL of an aqueous saturated sodium carbonate solution and the reaction vessel was flushed with saturated Na2CO3 solution (250 mL) and water (200 mL). After stirring of the mixture at 65° C. for 75 minutes the precipitate was allowed to settle down and the product was isolated by filtration and purified by multiple slurry of the solid in water (overall ca. 1000 mL). After drying of the crude product in vacuo at 40° C. overnight the solid was suspended in methylene chloride (20 mL), stirred for 45 minutes, isolated by filtration and washed with DCM (2×20 mL) and dried overnight. 3.53 g of an ochre solid (72% yield) could be obtained in a 99.5% HPLC purity. Further purification of the material was possible by gradient sublimation (initial amount: 1.00 g, sublimation yield: 67%).

Provenance & Evidence