[OTC] MDA:n synteesi helionista
- Thread starter Irving Langmuir
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- helional mda mda from helional
After switching Oxone, the acid comes out as you described! Thanks for your help! You mentioned in a follow up post that you resolved the amide formation issue, which work-up did you use?
Hi! sorry for the late reply, my way of doing things didn't work every time, and I wanted a reproducible method. I'm thinking of following the protocol in this video
, I think the large quantity of boric acid was a bit detrimental to the reaction. I'd advise you to follow the protocol in this video (which uses far less boric acid), and perhaps double the amount of boric acid used. Don't forget to transform the number of grams of benzaldehyde into the number of g of helional. I haven't tried the protocol in this video yet, but I think it works great. Once everything has melted, turn on the stirring and leave to react for 3 hours at 180°C. I'll do some tests to see which conditions are best when I have the time.
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What about this.
Helionic acid + Methanol +H2so4 = Methyl Helionate
Methyl Helionate + Ammonia solution = Amide + Methanol
This is the synthesis of Benzamide from methyl Benzoate
"That reflux/heat procedure is a PITA every time. A much better way is the ammonolysis of a benzoate ester.
Make methyl benzoate from the benzoic acid, then just mix it with concentrated aqueous ammonia and let it sit for a week. The ammonia base-catalyzes ester breakage, leaving the acid amide and the alcohol. Works great and the yields are typically high with this method. When I needed acetamide I did this with ethyl acetate.
After the week is up, just boil out the water/alcohol/leftover benzoate and you're left with benzamide, which you can either recrystallize or distill under vacuum."
Helionic acid + Methanol +H2so4 = Methyl Helionate
Methyl Helionate + Ammonia solution = Amide + Methanol
This is the synthesis of Benzamide from methyl Benzoate
"That reflux/heat procedure is a PITA every time. A much better way is the ammonolysis of a benzoate ester.
Make methyl benzoate from the benzoic acid, then just mix it with concentrated aqueous ammonia and let it sit for a week. The ammonia base-catalyzes ester breakage, leaving the acid amide and the alcohol. Works great and the yields are typically high with this method. When I needed acetamide I did this with ethyl acetate.
After the week is up, just boil out the water/alcohol/leftover benzoate and you're left with benzamide, which you can either recrystallize or distill under vacuum."
- By Candy450
-I've tried ethanol as a solvent three times, and it seems to form the ethyl ester of helionic acid, and other products depending on the pH. I haven't dug any deeper, so I can't tell you more. But perhaps we could form the amide from this ester, more simply than my current method (urea + boric acid + helionic acid).
ester + con ammonia solutio = amide + alcohol.
Use magnetic stirrer to this RM for few days at room temp. Let everything evaporate at room temp or use a desiccator bag with a drying agent like cacl. Heating it will cause the ester to break to acid and alcohol.
ester + con ammonia solutio = amide + alcohol.
Use magnetic stirrer to this RM for few days at room temp. Let everything evaporate at room temp or use a desiccator bag with a drying agent like cacl. Heating it will cause the ester to break to acid and alcohol.
Hi! You can form the ester by replacing the acetone with ethanol when oxidizing the helional with the oxone.
Ammonolysis of ester works badly because the leaving group is an alkoxide, so the reaction goes very badly.
I've finally found a great protocol for purifying the amide, which makes synthesis via boric acid and urea viable:
30g acid + 26g urea + 2.1g boric acid, heated to 180°C. Once melted, turn on the stirring. Then leave until there are hardly any gas bubbles forming (CO2 and NH3). This usually takes 3-4 hours. Leave to cool, then add 40mL of 5% ammonia solution and heat to boiling with stirring. Not everything will dissolve; these are the impure products of urea condensation. If the amide doesn't precipitate, evaporate some of the solution. once precipitated, filter.
Next, the impure amide is dissolved in a minimum of boiling xylene (or other apolar solvent with a high bp), then hot-filtered. It is possible that certain impurities form a brown liquid phase, in which case pour in the xylene, taking care to leave these impurities in the beaker, as they will remain at the bottom. You'll then see beautiful white amide crystals appear in the receiving beaker. Otherwise evaporates some xylene until crystallization.
The synthesis itself forms a lot of impurities. Whether or not the acid was pure to begin with made no difference to my tests. The amide obtained is really pure and forms beautiful white crystals.
During synthesis, I advise you to use a cooler that's not too big to let the water and ammonia escape (important for the equilibrium of the reaction). This will prevent the amide from escaping, as it tends to sublimate. Remember to wash the edges of the cooler too, to recover as much amide as possible.
I've also tried using Mg(NO3)2 hexahydrate as a catalyst (10% mol) in xylene at 140°C with 2eq urea, and that works too, but it takes 24h.
Ammonolysis of ester works badly because the leaving group is an alkoxide, so the reaction goes very badly.
I've finally found a great protocol for purifying the amide, which makes synthesis via boric acid and urea viable:
30g acid + 26g urea + 2.1g boric acid, heated to 180°C. Once melted, turn on the stirring. Then leave until there are hardly any gas bubbles forming (CO2 and NH3). This usually takes 3-4 hours. Leave to cool, then add 40mL of 5% ammonia solution and heat to boiling with stirring. Not everything will dissolve; these are the impure products of urea condensation. If the amide doesn't precipitate, evaporate some of the solution. once precipitated, filter.
Next, the impure amide is dissolved in a minimum of boiling xylene (or other apolar solvent with a high bp), then hot-filtered. It is possible that certain impurities form a brown liquid phase, in which case pour in the xylene, taking care to leave these impurities in the beaker, as they will remain at the bottom. You'll then see beautiful white amide crystals appear in the receiving beaker. Otherwise evaporates some xylene until crystallization.
The synthesis itself forms a lot of impurities. Whether or not the acid was pure to begin with made no difference to my tests. The amide obtained is really pure and forms beautiful white crystals.
During synthesis, I advise you to use a cooler that's not too big to let the water and ammonia escape (important for the equilibrium of the reaction). This will prevent the amide from escaping, as it tends to sublimate. Remember to wash the edges of the cooler too, to recover as much amide as possible.
I've also tried using Mg(NO3)2 hexahydrate as a catalyst (10% mol) in xylene at 140°C with 2eq urea, and that works too, but it takes 24h.
That is interesting. What are your yields in those 2 synthesis ? (boric acid / Mg(NO3)2) The fact that there is an alternative way to make the amide w/o those toxic Ni salts and hydroxylamine is a + Could you give a try on a small scale of Ammonolysis of the ester with ammonia ? It is working with ethyl/methyl benzoate, i do not see any reason why i would work here. Are you going to make a video on How To when you perfected thise method ? Or at least a summury write up of the synthesis.
About Hofmann rearrangement
There are plenty of video out there synth Hydrazine from urea. It is actually the same reaction but use the amide instead of urea. Yields are usually 50-60%
Use bleach and not anything else. The concentrataion doesnt matter, just use more. It is preferable to determine the % of your bleach before you procced because ofter the % is reduced. Gelatine is used in order to capture some ions because they are causing reduced yields. Nilered tried the reaction with HTH chlorinated tablets and failed.
About Hofmann rearrangement
There are plenty of video out there synth Hydrazine from urea. It is actually the same reaction but use the amide instead of urea. Yields are usually 50-60%
Use bleach and not anything else. The concentrataion doesnt matter, just use more. It is preferable to determine the % of your bleach before you procced because ofter the % is reduced. Gelatine is used in order to capture some ions because they are causing reduced yields. Nilered tried the reaction with HTH chlorinated tablets and failed.
That's nice but I did the forum protocol for the Hofmann rearrangement and it works. No need for chelating agents (like gelatin) as there is only hydrazine complexing with them, this is not the case with MDA freebasee.I've already seen these videos by the way.
I plan to make a summary when I have a perfect protocol.
I might try ammonolysis but as I explained it doesn't work well in general, thanks for your participation in this thread anyway!
I plan to make a summary when I have a perfect protocol.
I might try ammonolysis but as I explained it doesn't work well in general, thanks for your participation in this thread anyway!
