Author Topic: Iodination of 2c-h with I2 / silver sulfate  (Read 2856 times)

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Vaaguh

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Iodination of 2c-h with I2 / silver sulfate
« on: May 17, 2004, 10:42:00 AM »
To a 100 ml RBF containing a mixture of 2,54 g (10 mmol) iodine, 3,12 g silver sulfate (10 mmol) and 20 ml EtOH was added 0,91 gram of 2,5-dimethoxyphenylethylamine (5 mmol) dissolved in 20 ml EtOH.

After stirring for 30 hours the now bright yellow mixture was stripped from solvents. The residue was dissolved in 30 ml CH2CL2 and the solids where filtered off.



The organic phase was washed once with 15 ml 5% aqeous NaOH, once with 15 ml H2O and dried over MgSO4. After removal of the solvents the residue was dissolved in 30 ml acetonitrille and neutralized with aqueous HCl which resulted in the formation of solids. The crystals where washed twice with acetonitrille to provide white crystals weighing 0,36 g (20%). Mp: 244-247 °C




The yields are pretty bad but i'm fairly sure these are all bad technique on my side and the reaction was stirred for 30 hours instead of 17 because of severe weekend partying  ::)

Does anybody know if the recovered solids which are presumably silver iodide as it is a yellow solid can be converted back to the sulphate just by the addition of sulphuric acid? Or is does it first need to bee converted back to silver nitrate ?


Antoncho

  • Guest
Light
« Reply #1 on: May 17, 2004, 10:46:00 AM »
The rxn mixtr' has to bee protected from light.

That's a must, shall i say.



MoonLight

Vaaguh

  • Guest
Light
« Reply #2 on: May 17, 2004, 10:58:00 AM »
Oh that could bee an explaination as only 9 hours of the reaction ran in the dark  :(


Erny

  • Guest
amino group oxydation
« Reply #3 on: May 18, 2004, 08:56:00 AM »
The amino group must be protected; in original method by Mescalito 2C-H was first turned into sulphate, and only then reacted with iodine/Ag2SO4.

Procedure with silver sulphate is not siutable for a large-scale iodination, beecause too much solvent is needed.
When silver and 2C-H NITRATES are used instead of sulphates with mehanol as a solvent, it is possible to work with 6 g of 2C-H nitrate in 120 ml of methanol, though the more diluted the RM would be - the less side reactions would occur - IMHO.

_mu_

  • Guest
Bollocks. To quote https://www.rhodium.ws/chemi...
« Reply #4 on: May 19, 2004, 05:09:00 PM »
Bollocks.

To quote

https://www.thevespiary.org/rhodium/Rhodium/chemistry/doisynth.html

:

'The iodine/silver sulfate system has now been applied to the syntheses of iodomethoxy-amphetamines. [...] Protecting the amino group is not necessary under these conditions, and high yields are obtained.'

Reactions yielding ~5g of 2C-I are perfectly feasible.

Erny

  • Guest
Re: Bollocks
« Reply #5 on: May 20, 2004, 04:26:00 AM »
Firstly:

Post 464980

(Antoncho: "Iodinations of 2C-H/2,5-DMA", Chemistry Discourse)


Secondly: Should I type it once again, after Antoncho and Mescalito? Well: in mescalito's experiences the freebase-amine was only once successfully iodinated - the first time, and we have never succeeded in repeating that experiment. In all other attemts we have made the aminogroup was not removed only if it was protected by protonation.

That is practice, something SWIM have seen with his own eyes and not a reference to some publication (even if it is by Shulgin) or a doubtful hypothese the Big Hive is being full of.

By the way, amphetamines seem to be more stable in theese conditions, than PEAs (again, see the reference above).

Reactions yielding ~5g of 2C-I are perfectly feasible

What about 25 g? 5 g is too little, you know  ;)