Sodium Hydroxide → 9,10-Anthracenedione, 2,3-dihydro-1,4,5,8-tetrahydroxy-

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Reaction Conditions

Reaction Steps

The 1,8-dihydroxy-4,5-diaminoanthraquinone-2,7-disulfonic acid reaction mixture prepared as in Example 5c, was cooled to 70°C. It was then treated with 117 parts of 50% sodium hydroxide solution and 70 parts of sodium hydrosulfite. The mixture was heated to 78° to 100°C and held at that temperature for 1 hour. It was then cooled to 60°C and filtered. The product was washed with dilute sodium sulfate solution containing about 1% of sodium hydrosulfite and the washed cake was immediately slurried in 10 to 15% sulfuric acid. The filtration of the product and drying yielded 20 parts of leuco 1,4,5,8-tetrahydroxyanthraquinone.

Provenance & Evidence