Hi. So I have been piecing a synthesis together to make the smoke dye DR9 and so far I have processes for producing most of the chemicals leading up
to it but I cannot find a synthesis for the final product anywhere. The best thing that I can find is a list of chemicals from
"https://www.worlddyevariety.com/disperse-dyes/disperse-red-9.html". If anyone knows how to produce this specific chemical or anything similar I would
greatly appreciate it.
[Edited on 10-12-23 by MrFormula]Lionel Spanner - 12-10-2023 at 14:01
To my mind, the best route would be to prepare 1-aminoanthraquinone, then carry out reductive amination with formaldehyde to produce the N-monomethyl
derivative. 1-aminoanthraquinone can be made by sodium sulphide reduction of 1-nitroanthraquinone, which in turn can be made from aromatic nitration
of anthraquinone.
Alternatively, 1-aminoanthraquinone can be made by a substitution reaction of anthraquinone 1-sulphonic acid with ammonia.Boffis - 13-10-2023 at 12:05
Just a few points that I would like to raise. Why have you included the preparation of boric acid and sodium chlorate while assuming that anyone
trying to follow your method has access to fuming sulphuric but not boric acid (ex Ebay?) and a chlorate salt. Surely an amateur friendly method would
avoid oleum since it is hardly OTC and very hard to prepare.
Secondly, your method of producing sodium chlorate from bleach is hopelessly inadequate. Simply boiling down bleach until you get crystals results
only in salt! Any chlorate remains in the liquor and obtaining sodium chlorate from it even reasonably pure, say>90%, is fraught with difficulty.
It is far better to go like this; after removing the first crop of salt crystals the solution is mixed with half its volume of saturated potassium
chloride and placed in the fridge for 12 hours and the potassium chlorate filtered off. For your purposes a single recrystallisation would be
adequate. You would need to use more K chlorate than sodium chlorate.
As to avoiding the use of oleum, I think Lionel Spanner's idea of going via nitroanthraquinone has some merit. I haven't tried nitrating anthraquinone
but I suggest you take a look at Lauth, Comptes rendus de l'Academie des sciences, v137, p662; or check out B. Barrie's "Anthracene and Anthraquinone"
first page of chapter IX explains that potassium nitrate may be used to nitrate anthraquinone dissolved in conc. sulphuric acid. Details are sketchy
but it comes down to only one unknown: the solubility of anthraquinone in conc. sulphuric acid.
If you go via the 1-chloroanthraquinone I presume you were going to react it with ammonia to obtain the 1-aminoanthraquinone. If so, could you react
it with methylamine solution and obtain your desired product this way? I have seen a few old German patents that indicate that the nitro group in the
1-position can be replaced directly by an amine group. So the route anthraquinone - 1-nitroanthraquinone - 1-(methylamino)-anthraquinone is worth
checking out.Kloberth - 15-10-2023 at 13:25
I would go with the 1-nitroanthraquinone to 1- aminoanthraquinone to the DR9.
The nitration of the anthraquinone seems to work: https://prepchem.com/1-nitro-anthraquinone/
Then reduction to the amine, wikipedia tells us to use NaS but other rdducing agents should also work.
Then the last step would be methylating the amine i guess using formaldehyde solution and zinc would work for this.MrFormula - 16-10-2023 at 04:58
Thanks all for the information. I will edit my synthesis and look into the nitration of the anthraquinone.MrFormula - 16-10-2023 at 08:30
Thanks all for the information. I will edit my synthesis and look into the nitration of the anthraquinone.MrFormula - 17-10-2023 at 07:11
Then the last step would be methylating the amine i guess using formaldehyde solution and zinc would work for this.
Would anything else besides formaldehyde work?MrFormula - 17-10-2023 at 14:49
Actually, on second thought, would it be possible to directly react the 1-nitroanthraquinone with the methlyamine?unionised - 18-10-2023 at 02:30
I know it's not the same thing but be aware of how similar your intermediate is to this https://en.wikipedia.org/wiki/3-Nitrobenzanthrone
which got the
"highest score ever reported in the Ames test, "MrFormula - 18-10-2023 at 15:41
