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Author: Subject: Easy TMA-2 Synthesis
ChemicallyImbalanced
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cool.gif posted on 22-2-2005 at 10:19
Easy TMA-2 Synthesis


I found this synthesis on another forum (it was obviously taken from Rhodium's page) and it seems nice and simple, but I have a few questions before I proceed. Here is the synthesis...


2,4,5-trimethoxyphenyl-2-nitropropene

To a solution of sodium nitrite (13.24 g, 192 mmol) and ethylene glycol (8.93g, 144 mmol) in 20 mL of water, a solution of asarone (10g, 48 mmol) in 150 mL of ethyl acetate was added followed by addition of iodine (18.28g, 72 mmol) at 0°C. The reaction mixture was stirred at room temp for 48 hrs under nitrogen and then was poured into a separatory funnel together with ethyl acetate and partitioned. The ethyl acetate solution was successively washed with water, aqueous 10% thiosulfate and aqueous saturated NaCl. After drying over anhydrous magnesium sulfate, the ethyl acetate solution was evaporated to to obtain the crude product as dense dark yellow crystals, containing some unreacted asarone. The product was recrystallized from alcohol to afford 2,4,5-trimethoxyphenyl-2-nitropropene (2-nitroasarone) in 75%+ yield.



Reduction of 2,4,5-Trimethoxyphenyl-2-nitropropene to TMA-2

To a solution of 1ml 31% HCl, 40g NiCl2.6(H20) in 350ml EtOH in a 500ml beaker at 50°C is added 35g of shredded Al (regular Reynolds foil) slowly over a 3.5 hour period, when evolution of hydrogen had ceased the rxn was a viscous gel. This was placed in a 4l beaker and rinsed several times with tap water, each time allowing suspension to settle before decanting. This precipitated nickel was air dried overnight on a filter paper (Note: larger pieces of foil were removed).

10g of the above catalyst was placed in a beaker containing 385 ml 40% aqueous AcOH and 89g NaCl at 70°C for 7 minutes, then the solution is decanted and the Nickel rinsed with 60°C dH2O, then rinsed with EtOH then placed in a 500ml Erlenmeyer flask containing 250ml EtOH and charged with 20mmol TMP2NP (5g). With moderate overhead stirring, 10g of Al is added 1g at a time followed by a 3ml aliquot of 31% HCl with each addition. Addition takes 2 hours; it is then allowed to stir an additional hour while evolution of hydrogen subsides. Rxn become one viscous gel to which 100ml EtOH is added with stirring. Rxn is then slowly basified with 50% NaOH. After AlO has settled the alcoholic overhead is decanted and the sludge extracted with 100ml toluene. The EtOH is stripped off using low vac on a water bath, the residue being taken up with the toluene extract. Extract was washed 1x w/ saturated aqueous NaCl and 1x with dH2O. This is dried over MgSO4. Pre-gassed toluene is added in small aliquots with precipitated crystals being vac filtered between aliquots.

Yield: 10mmol TMA2.HCl (2.5g) 50% Molar yield




OK.... now some questions.

1. What are the solubilities of TMP2NP? How exactly should I recrystallize it?

2. It says "was poured into a separatory funnel together with ethyl acetate and partitioned." How much ethyl acetate should I add?

3. After the catalyst is made it says that large pieces of foil where removed. Why not remove them all?

4. It says "After AlO has settled the alcoholic overhead is decanted and the sludge extracted with 100ml toluene. The EtOH is stripped off using low vac on a water bath". Why would you need to srip off the EtOH when it was already decanted? Also, shouldn't this be filtered first to remove AlO before extracting with toluene?

5. Would it be ok to use denatured alcohol in this synthesis or would the MeOH etc cause problems?

6. It says "Rxn is then slowly basified with 50% NaOH." What should the pH be? Would 11 be ok?

7. What's a good cheap source of nitrogen besides going to a gas supplier if you have your own cylinder?

8. Is it really necessary to use pre-gassed toluene? Couldn't I just gas the toluene/freebase?


[Edited on 22-2-2005 by ChemicallyImbalanced]
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[*] posted on 22-2-2005 at 12:30
Are you a bee?


The admins, mods and alot of the members of this board have decided that posting sources here is acceptable practice. Which is cool.

OTOH the admins and mods of the hive made a decision that because of the nature of the discussions taking place there, the posting of sources was not acceptable at the hive, so source posting was banned...a strict no-no.
I happen to agree with that decision....it makes sense for quite a few reasons.....and it's a big part of the reason I voluntarily choose not to engage in the discussion of controlled drugs here as well.
Intermediates are another matter entirely. ;)

Can I take it that you disagree with the hive policy and feel sources and drug synthesis discussions are compatible on the same board and if so why so?

I am not being confrontational about this either by the way but it's not a policy I seem to remember ANY bees challenging or even questioning at the hive, or should I say any bees outside the stims forum, and yet I see so many here who seem to have abandoned it as a reasonable code of conduct.
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ChemicallyImbalanced
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[*] posted on 22-2-2005 at 13:05


"Are you a bee?"


I'm a loyal follower of the D.A.R.E program. :D
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[*] posted on 22-2-2005 at 14:16


D.A.R.E to bee... Think. Exist.



\"I love being alive and will be the best man I possibly can. I will take love wherever I find it and offer it to everyone who will take it. I will seek knowledge from those wiser and teach those who wish to learn from me.\" Duane Allman
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[*] posted on 22-2-2005 at 15:06
sorry


This is too close to cookbook-chemistry for my tastes. I don't mind discussions of chemistry here, but in the case of not-novel drugs or energetic materials, I prefer that discussions consist of more or less than "how do I make this recipe work?" Perhaps you should look for answers on your own, then ask the (few) questions that you can't find answers to here. Or just ask the inhabitants of the forum where you originally got these instructions.



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