Author Topic: Short Questions Thread  (Read 10824 times)

timecube

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Re: Short Questions Thread
« Reply #460 on: April 12, 2010, 04:28:32 AM »
How are you condensing o-flouroaniline with piperidine?  Do you mean with 4-piperidone, or via some other means?

Naf1

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Re: Short Questions Thread
« Reply #461 on: April 12, 2010, 04:33:41 AM »
Sorry the 4-piperidinone previously discussed (N-Phenethyl-4-piperidinone) is condensed with o-flouroaniline.
« Last Edit: April 12, 2010, 04:36:39 AM by Naf1 »

akcom

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Let's talk about oximes, baby
« Reply #462 on: April 12, 2010, 09:08:31 PM »
So lets talk about oximes. If one is looking to prepare MDA from the corresponding ketones on the 100mL scale what problems might one run into? I know people complain about the reduction not scaling well using Al/Hg, but I'm really more interested in the oxime formation. Can one perform this reaction at the 100mL scale with magnetic stirring or would mechanical stirring be required? What else do I need to worry about?

Naf1

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Re: Lets talk about oximes baby
« Reply #463 on: April 12, 2010, 11:27:00 PM »
Its pretty straight forward! You can use a magnetic stirrer for up to 1 liter easily if you have a good stirbar and stirrer. But I know of people that have stirred then left overnight without further stirring and everything turned out fine. I would focus on the subsequent reduction as thats harder than oximation.

akcom

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Re: Lets talk about oximes baby
« Reply #464 on: April 13, 2010, 12:03:32 AM »
Alright, any suggestions on what route to proceed with for the reduction?  If one could obtain sodium metal fairly easily, would that be a decent way to go?  I really want to avoid the Al/Hg as it seems low yielding and/or temperamental.  Thanks for the help Naf1!

Naf1

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Re: Short Questions Thread
« Reply #465 on: April 13, 2010, 12:59:05 AM »
Cough..Cough..Zinc dust (2.6 eq.) and copper sulfate (1.4 eq.) were suspended in 65% aqueous ethanol and sonicated (Bransonic 1200) for eight minutes at 60°C, then a solution of oxime was added, and the reaction continued for approximately three hours. Cough. Cough...Cough....

Wow thats a bad cough, lucky no one saw as it would have appeared I was spoonfeeding you ;D

NeilPatrickHarris

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Re: Short Questions Thread
« Reply #466 on: April 15, 2010, 01:26:06 PM »
stupid general chem question about if one were to subtitute (NH3OH)2.SO4 instead of NH2OH.HCl....
so if there was (NH3OH)2.SO4 in solution which was slowly basified with Na2CO3, what would the product look like

is this correct for what's happening when you basify NH2OH.HCl?
NH2OH.HCl + Na2CO3 -> NH2OH + NaCl + NaHCO3

then what happens when you basify (NH3OH)2.SO4?
(NH3OH)2.SO4 + Na2CO3 -> NH2OH + NH2OH + Na2SO4 + H2O + CO2

i probably have this wrong but does that look right?
« Last Edit: April 15, 2010, 02:49:47 PM by NeilPatrickHarris »

Enkidu

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Re: Short Questions Thread
« Reply #467 on: April 15, 2010, 06:14:31 PM »
That's right

NeilPatrickHarris

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Re: Short Questions Thread
« Reply #468 on: April 15, 2010, 06:36:45 PM »

Sedit

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Re: Short Questions Thread
« Reply #469 on: April 15, 2010, 11:00:24 PM »
If an Ether Solution of Ammonia is added to an amine salt this should covert the Salt into freebase + Ammonia chloride correct? Just like basifiy but no water present but im assuming the mechanics should stay the same I just want to be sure.
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Naf1

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Re: Short Questions Thread
« Reply #470 on: April 15, 2010, 11:08:57 PM »
Yeah it creates NH4Cl

Evilblaze

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Re: Short Questions Thread
« Reply #471 on: April 15, 2010, 11:36:02 PM »
Not short, but question....

So:
The main idea would be to make 3,5 dimethoxy 4 ethoxy benzaldehyde from vanillin. The reaction would go in 3 steps:


In the first step the vanillin would be reacted with bromine to form 5 bromo vanillin. This is a simple halogenization in GAA, according to /1/

The second step would be reacting the 5 bromo vanillin with sodium methoxide. The idea is to make a NaOMe solution from sodium and methanol and add this solution to another solution what is 5 bromo vanillin dissolved in MeOH. NaBr crystals should be filtered and the solution should be diluted with water, the 5 methoxy vanillin should be extracted with ether. Actually no reference, but this is not a hard reaction....

Now let's see the problematic part... The alkylation with diethyl malonate [This should probably be oxalate - Enkidu]. This reaction works with most phenols, according to ref /2/. The question part is, that how to separate the different compounds.... Maybe a column chromatography would be a good idea... Or react the remaining phenol with something.... FeCl3 or just make a sodium salt with NaOH what is less/or not soluble in ether. Any ideas?

Or start the reaction with the alkyltion of the vanillin with diethyl malonate... But the problem is still there...  4 ethoxy vanillin is not easily separated from the vanillin.

And I want to use "OTC" ethylting agent and not diethyl sulfate or something like that...

Any ideas?

/1/: http://www.erowid.org/archive/rhodium/chemistry/mmda.mescaline.html
/2/: Read the pdf what is posted....
« Last Edit: April 16, 2010, 03:11:24 AM by Enkidu »

Naf1

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Re: Short Questions Thread
« Reply #472 on: April 16, 2010, 12:18:18 AM »
You must have seen the post I made yesterday!
http://127.0.0.1/talk/index.php/topic,914.msg11119.html#msg11119
After posting it I was searching and found a patent and a rhodium archive page with a similar technique (probably more efficient) with vanillin, using hydrolysis of the formed halide to form the diol;

PROCESS FOR THE PREPARATION OF 2,4,5-TRIMETHOXYBENZALDEHYDE
The title has a typo, it is really 3,4,5-trisubstututed
http://www.freepatentsonline.com/3855306.html

Novel highly selective catalytic oxychlorination of phenols
Luciano Menini and Elena V. Gusevskaya
DOI: 10.1039/b513329g

The highly selective oxychlorination of various phenols
catalyzed by CuCl2 under mild conditions, in which chloride
ions are used as chlorinating agents and dioxygen as a final
oxidant, has been developed.

http://www.rsc.org/delivery/_ArticleLinking/DisplayArticleForFree.cfm?doi=b513329g&JournalCode=CC

If you read that paper above you will be pleasantly suprized to find Eugenol is used as an example for around 82% yields.

Happyman

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Re: Short Questions Thread
« Reply #473 on: April 16, 2010, 05:36:45 AM »
I am wondering about chlorinating amino acids. Can it be reasonably done? Would a strong chlorinating agent like phosphorus pentachloride be able to do the trick? I just had a window about it open but I won't be back until tomorrow so I thought I might as well throw it out there first.

Naf1

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Re: Short Questions Thread
« Reply #474 on: April 16, 2010, 06:01:32 AM »
You would need suitable amine protection to start with....

Evilblaze

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Re: Short Questions Thread
« Reply #475 on: April 16, 2010, 11:55:20 AM »
You must have seen the post I made yesterday!

PROCESS FOR THE PREPARATION OF 2,4,5-TRIMETHOXYBENZALDEHYDE
The title has a typo, it is really 3,4,5-trisubstututed
http://www.freepatentsonline.com/3855306.html

Novel highly selective catalytic oxychlorination of phenols
Luciano Menini and Elena V. Gusevskaya
DOI: 10.1039/b513329g

I didn't saw your post, the idea was based on, that I got some pure vanillin recently and what can be this thing used for?:D

The original synth is doesn't looks too good for me, everywhere they use dimethyl sulphate, dimethyl carbonate, trimethyl phosphate and so on... These are not so friendly chemicals and they are not easily obtained. This why I want to go on an easier way.

My last post was wroted at 2 a.m. and the malonates in the text are oxalates.... I was really tired... Sorry.

I thing that the chlorination/bromination won't be a big problem, there are several recipes and several reagents for this with really good yields.

The reaction with NaOMe is also not a problem...

The ethylation and the separation of the different compounds... That's a problem....
« Last Edit: April 16, 2010, 12:01:46 PM by Evilblaze »

Happyman

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Re: Short Questions Thread
« Reply #476 on: April 17, 2010, 01:13:06 AM »
You would need suitable amine protection to start with....

Yes. That is what I am worried about. I admittedly do not know much about amine protection.

Sedit

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Re: Short Questions Thread
« Reply #477 on: April 17, 2010, 01:18:19 AM »
Suppose you have a mixture of a the following because I think something would be strange if this was the case,,,,

You have,
    A heavy amine with a high BP and
    Ammonia gas dissolved in the following mixtue of solvent.
    The solvent system consist of (highest to lowest)Heptane and Diethylether.
    The entire system would be anhydrous
   
All Non solubles could have been filtered completely to leave a light yellow Solvent solution.
This solutions volume could have been completely reduced until no more Ether is smelled leaving a small amount of semi thick golden oil smelling of amine
This is done to remove the solvent that contains the Ammonia.
There is only a trace of oil left over prehaps some Heptane due to its closeness to the BP of water which it was evaporated on.(a low temperature water bath) but it mostly smells of amine.


Now if this was the case and someone did all of these perimeters and attempted to add Muratic acid to the oil in an attempt to turn the amine to its HCl salt and had the following unusuall thing happen what would be your explination?

When the fumes of HCl (and when slowly dripping in) the HCl forms wisp of smoke simular to ammonia chloride vapors. This person thought ok maybe in an unlikely event its ammonia still present so they made damn sure to reduce the volume as much as can be and added IpOH and evaporated again to try to entrain any NH3 that might bet here to leave. This still Occured no matter what was done.

To make matters worse there is oil present that no matter how low this person makes the PH it still is present and worst of all still smells of amine even though evaporation yeilds amine hcl crystals with contamination....

Has anyon ever added 34% HCl slition directly t warm Freebase amine and seen wispy smoke?


Side question..... Whats does Heptane smell like. Is there any way it could be confused with amine smell?
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Naf1

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Re: Short Questions Thread
« Reply #478 on: April 17, 2010, 01:41:27 AM »
NO way you would confuse heptane with amine, heptane has an analogous smell to gasoline (as gasoline is mainly treated heptane and octane and some other anes like pentane with additives). Neutralizing your solution with a good thorough stir should remove ammonia, whenever I have a decent amount of free amine especially in a warm solution there is a fairly strong amine smell (analogous with ammonias smell, not strong enough to actually burn your nostrils like ammonia though). My 35% HCl has a pretty steady stream of white fumes leaving the container, I have had similar circumstances where the product was scorched and melted into a useless black oil. I would personally add a more dilute conc of HCl and see if that pulls alot more into solution instead of melting it into a ball, and try and stir that oil into solution with a long stir in more dilute HCl. As sometimes HCl gas does less damage and is better than very strong HCl with H2O present, if you add say enough 10% HCl and stir for half an hour any oil left is going to be either your impurity, scorched product or polymerization so should be separated (but not thrown out! just in case).

edit; You would evap that acid solution and see if your yield was there, I am guessing it would be. But I have found that HCl gas is very reactive so as soon as bubbled in it forms the HCl salt as soon as it contacts the amine pushing the salt out straight away (instantly). So the time your target molecule is in contact with excess conc acid is very very short, opposed to HCl with H2O present which once reacted to form the salt. It then dissolves the molecule into a much higher concentration of HCl, in solution with high concentration acid it has a much better chance to further react depending on the molecule in question.
« Last Edit: April 17, 2010, 02:02:12 AM by Naf1 »

Enkidu

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Re: Short Questions Thread
« Reply #479 on: April 17, 2010, 02:08:10 AM »
How do you know that you only have the amine (besides solvent and ammonia) in there? maybe the oil is a side product or an unreacted precursor to your amine...