Sciencemadness Discussion Board

1,8 dyhdroxyanthraquinone

fausap - 23-9-2020 at 21:19

Hello all,

could you help me with the following reaction (if this is possible):


C14H8O4 + 2LiOH → C14H6O4Li2 + 2H2O

I have a dark red (almost black) residual insoluble.
Is the above reaction possible, or something else is happening?

thanks,
Fausto

njl - 24-9-2020 at 05:47

can't tell if this is a troll or not. No, that is not what is happening. I'm pretty sure it's just the phenolic portion of the molecule polymerizing.

Boffis - 24-9-2020 at 11:43

No I don't think LiOH will polymerise a hydroxy anthraquinone but you will need to give us a fair bit more information if you want a sensible answer and people to put in the effort of replying. Like solvent, temperature etc and where did the anthraquinone come from since the 1,8 motife is one of the less common one (1,2 = alizarin, 1,4 = quinizarin, 2,3 = hystizarin: the 1,8 is chrysazin a well know laxative found in rhubard and prepared from aloes resin). If its from a natural source its probably not pure but pure it may form a lithium salt, probably as an inner complex.

fausap - 25-9-2020 at 03:21

Quote: Originally posted by njl  
can't tell if this is a troll or not. No, that is not what is happening. I'm pretty sure it's just the phenolic portion of the molecule polymerizing.


Is the question so strange, that I should be a troll? :)
This is amazing....

fausap - 25-9-2020 at 03:26

Quote: Originally posted by Boffis  
No I don't think LiOH will polymerise a hydroxy anthraquinone but you will need to give us a fair bit more information if you want a sensible answer and people to put in the effort of replying. Like solvent, temperature etc and where did the anthraquinone come from since the 1,8 motife is one of the less common one (1,2 = alizarin, 1,4 = quinizarin, 2,3 = hystizarin: the 1,8 is chrysazin a well know laxative found in rhubard and prepared from aloes resin). If its from a natural source its probably not pure but pure it may form a lithium salt, probably as an inner complex.


Sure, sorry to be so terse in my question.

I prepared a 1L of 0,5N LiOH solution and I dissolved 6g of 1,8-dihydroxyanthraquinone. The temperature of reaction was 45C
The "quinone" is not from a natural source, and it's 98% pure, according to the manufacturer.

thanks,
Fausto