Reaktion #487509

Reaktionsgleichung

sulfuric acid

sulfuric acid

alizarin

→

purpurin

Lösungsmittel

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigehad been prepared
2. 2
   Temperaturcooling
3. 3
   workup.ADDITIONwas added over 1 hour to a reaction liquid
4. 4
   Sonstigethe reaction liquid
5. 5
   Waschenbeing washed with 400 mL of water
6. 6
   Filtrationfiltered
7. 7
   FiltrationThe crystal collected by filtration
8. 8
   Waschenwas washed with 300 mL of methanol
9. 9
   Sonstigedried

Vorschrift

A suspension of 17.5 g of manganese dioxide/40 g of concentrated sulfuric acid, that had been prepared by putting 9.0 g of water and 130 g of 96% sulfuric acid into 30 g of alizarin (manufactured by Sigma-Aldrich Corporation), followed by ice-cooling, was added over 1 hour to a reaction liquid while maintaining it at 10° C. or lower. After 2 hours, the reaction liquid was poured into 1 L of water, with the inside of the container being washed with 400 mL of water, and filtered. The crystal collected by filtration was washed with 300 mL of methanol and dried to obtain 32.4 g of purpurin.

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