2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → HCID 11096910, compound

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Reaction Steps

To a solution of 1,2,3,4-tetrahydro-6,7-dimethoxy-3-isoquinolinecarboxylic acid, methyl ester (19.77 g, 78.7 mmol) in 400 ml of tetrahydrofuran, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (39.3 g, 173.1 mmol) was added. The dark solution was heated under reflux overnight. The resulting precipitate was filtered off, dissolved in 500 ml dichloromethane/water 1:1, and the pH was adjusted to 10 by means of 1N sodium hydroxide. The phases were separated, the aqueous phase extracted once with dichloromethane and the combined organic phases washed twice with 100 ml of water containing a few drops of 1N sodium hydroxide. After the drying and evaporating of the solvent, 9.20 g of the title compound was obtained; melting point 214.9° C.

Provenance & Evidence