Réaction #487509

Équation de réaction

sulfuric acid

sulfuric acid

alizarin

→

purpurin

Solvants

water

water

Conditions de réaction

Traitement

1. 1
   Autrehad been prepared
2. 2
   Températurecooling
3. 3
   workup.ADDITIONwas added over 1 hour to a reaction liquid
4. 4
   Autrethe reaction liquid
5. 5
   Lavagebeing washed with 400 mL of water
6. 6
   Filtrationfiltered
7. 7
   FiltrationThe crystal collected by filtration
8. 8
   Lavagewas washed with 300 mL of methanol
9. 9
   Autredried

Mode opératoire

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.

Source