Author Topic: Results of a quick DEET--HCl-->Diethylamine experiment (Read 137 times)

JohnSanders · « **on:** November 01, 2009, 01:00:12 AM »

I was doing a quick look through my log of experiments and I saw that my last test with a hydrolysis and distillation of DEET to Diethylamine was unsuccessful, so I decided to try something else.

After a few months (6-8) of leaving a mixture of DEET and HCl in a test tube, I decided to do a small scale distillation and see if the HCl had hydrolyzed over time. (the solution was a pH of 4 if I remember correctly.) I currently am waiting for a new distillation app, since my old one took a tumble when I was carrying it in a box... (god, that was a waste of 500 dollars, all I saved was my column.)

I poured ~5ml of Deet and HCl into a small beaker with a distillation arm on it, and just sat an open flame under neath it. I knew the dangers of this at the time, and really didn't mind, I figured if anything happened, it wouldn't be enough to do much harm.

After about five minutes I started to see some white smoke come off the beaker. Meaning the rigorous boiling was yielding something. Either DEET (Most likely, or Diethylamine.) After seeing this smoke, I proceeded to stopping. My experiment was complete when my eyes started to burn, my nose was hurting and I saw halos around the lights in my lab.

Meaning, a prolonged solution of HCl (36% muriatic acid) and DEET will hydrolyze over time. Or one could simply go over the original method of using sulfuric acid to lower the pH to around 4, hydrolyze at 70-80C until homogeneous, then distill the Diethlyamine.

Just thought I'd share, I'm trying to make this place more about yields and less about theoretical

Sedit · « **Reply #1 on:** November 01, 2009, 01:09:41 AM »

Thanks for sharing.

Not to nit pick but perhaps Im missing something. If you attempted to perform the hydrolysis with HCl followed with a distillation creating a white smoke how could that possibly be Diethylamine when that will be locked away as the Hydrogen Chloride salt in this case. I would think it is far more likely that the white cloud was dense HCl fumes comming over from the excess HCl in the solution.

Try to slowly evaporate the solution to dryness and then titrate with a 10% NaOH solution to see if that frees any NH(Et)2*HCl.

BTW: when I get the chance I will merge this with existing DEET hydrolysis thread.

JohnSanders · « **Reply #2 on:** November 01, 2009, 01:22:37 AM »

That was also a thought, but if it was a dense cloud of HCl, then it wouldn't be white. Not to mention it would be denser than air, so when the cloud rose up, this disproved it. Though it was a good thought. The reason it could be DEA, is because either A) The salt was evaporated, I believe the boiling point is 320C, which is extremely high for a simple lighter that I used, but the heat of the flame is well over 1000C, so it seems possible. or B) It didn't form the salt, since the con. of the HCl was diluted to such an extreme that the 2-3 ml of DEA would have used all the HCl, leaving well over ~1-2ml of un-salted DEA. Seeing as how it is a gas at room temp, this even makes more since.

What do you think?

Naf1 · « **Reply #3 on:** November 01, 2009, 01:56:04 AM »

I was just working with HCl gas 5 minutes ago! The fumes are indeed white and so is H2SO4 but HNO3 fumes are red. And HCl gas does rise and increases in volume with heat (it may be denser than air, but when mixed with it and heat it goes for the ceiling), and god is that nasty shit! burns the nostrils and if it gets up to a high enough concentration in the air it also burns the eyes throat etc. Has a very distinctive sharp metallic smell and could not be confused with the fishy ammonia smell of diethylamine, you did have a very fishy/ammonia smell didnt you?

JohnSanders · « **Reply #4 on:** November 01, 2009, 01:58:30 AM »

I guess there is nothing like field experience then. My source of information told me that HCl gas was more denser than air, and was not white. Well, in that case it comes down to smell.

But, sadly I can't remember what it smelled like, I just remember leaving. I guess that leaves this un-decided.

Sedit · « **Reply #5 on:** November 01, 2009, 03:06:37 AM »

Well its ok that you left instead of breathing in the air for a little bit more data

... Yes my dumb ass has done that before after an accidental overheating of H₂SO₄

I have never smelled Diethylamine but if its anything like methylamine you would not forget it at all and the fact that your lab will smell like low tide at the pier for a week will remind you.

Quote

believe the boiling point is 320C, which is extremely high for a simple lighter that I used, but the heat of the flame is well over 1000C, so it seems possible.

This is a non issue to be honest because the temperature of a solution can not rise above its lowest boiling partion to any major extent(minus azeotropes and salt solutions for simplicity). IE if its mostly water it can not go higher then 100C and the 1000c flame will do nothing more then increase the spead at which the H₂O vapors leave the system.

On the issue of left over unsalted amine. Without knowing off hand the PH of diethylamine I would have to say that with the PH 4 you mentioned before I would bet that all of your DEAmine was in its salt form.

As far as the data you have seen on HCl fumes you must keep in mind that they are invisible. If you have ever "seen" dry HCl it has no visual indicators that its there at all. When it mixes with H₂O from the air is when you get the vapors you normaly see. The fact that you where boiling it means there was a large concentration of H₂O and HCl in the flask making the appearent white fumes you see.

PS:BTW Naf, HNO3 fumes are not red they are indeed simular to HCl when in extemely concentrated form. When it is heated the red fumes you see are not HNO3 but the decomposition products NO_x which are generaly avoided or atlest tried to when distilling HNO3.

Naf1 · « **Reply #6 on:** November 01, 2009, 03:40:56 AM »

I have never had HNO3 above 70%, but the 70% laboratory reagent HNO3, once the lid is removed blood red fumes come off!

edit; The acid was also a pale yellow color, which would indicate the presence of nitrogen dioxide (which is why it would have fumed red).

LINK

JohnSanders · « **Reply #7 on:** November 01, 2009, 03:42:30 AM »

Well in that case, it seems my experiment was just plain stupid! Thanks for clearing that up.

Seems you must reflux for hydrolysis to occur, no matter how long it stays.

Sedit · « **Reply #8 on:** November 01, 2009, 04:07:15 AM »

No experiment is stupid at all. Look at Sedits random experiment thread for examples

. They may not look like much or make much sence to some for that matter but the information those little fuckups and splish splashes gave me were priceless.

Many hydrolysis do infact take place at lower temperatures but they happen very slowly. The fact that we are talking a level of months here means it may have taken place. Just boil away your solution to retrieve your salt. If you are left with a solid that would be good sign #1. Addition of base should yeild and amine smell of some kind. That would be good sign #2. If all this looks good then a distillation of the Diethylamine base is in order to quantify the effectiveness of your experiment.

Try right now if still possible to raise the PH of a small sample(couple drops) of your solution. Best way would be to take an eye dropper and drip the solution on a small amount of NaOH prill. Wait a second or two at the most for any serious fumes to subside and smell. If it smells like amine you are looking good to slowly dry the solution down to solid and follow the processes stated above.

Naf the fact that your HNO3 already contained lower oxides explains the reason that the vapors where colored with them. As the NO oxides where oxidised in the atmosphere they will more then likely take on the even deaper color of NO2.

JohnSanders · « **Reply #9 on:** November 01, 2009, 04:18:58 AM »

I should have done that, but I already dumped the ~5ml of solution. Maybe if I want to wait another 8 months, I can start again. There isnt a way to find out how long the hydrolysis would take without high temperatures, is there?

Sedit · « **Reply #10 on:** November 01, 2009, 05:41:17 AM »

Find out the rate constant of the hydrolysis reaction....IE... don't ask me

Sedit · « **Reply #11 on:** November 01, 2009, 06:27:10 PM »

I thought of something that will make your job a bit easier John. Seeing as how the nitrogen on DEET is tied up it should not be able to react with Copper salts the way that amines do producing a deap blue solution. Next time if you want to test if any hydrolysis took place perhaps a Copper sulfate solution dripped into a few drops of the DEET solution will give you the information you want without the time consuming workup of the reaction.

I don't know how you could figure out concentration going by the color of the solution but it should indeed tell you if hydrolysis took place at all.

This thread is also better suited for the General chemistry forum since it does not discuss the synthesis of any bioactive compounds.

heisenberg · « **Reply #12 on:** November 02, 2009, 03:25:43 PM »

HNO3 gas, when without any NOx contamination, appears as a white smoke. As a liquid, it looks totally clear. NOx impurities can be avoided by distilling under vacuum, and by slowly adding a very small amount of urea to the solution.

Author Topic: Results of a quick DEET--HCl-->Diethylamine experiment (Read 137 times)

JohnSanders

Results of a quick DEET--HCl-->Diethylamine experiment

Sedit

Re: Results of a quick DEET--HCl-->Diethylamine experiment

JohnSanders

Re: Results of a quick DEET--HCl-->Diethylamine experiment

Naf1

Re: Results of a quick DEET--HCl-->Diethylamine experiment

JohnSanders

Re: Results of a quick DEET--HCl-->Diethylamine experiment

Sedit

Re: Results of a quick DEET--HCl-->Diethylamine experiment

Naf1

Re: Results of a quick DEET--HCl-->Diethylamine experiment

JohnSanders

Re: Results of a quick DEET--HCl-->Diethylamine experiment

Sedit

Re: Results of a quick DEET--HCl-->Diethylamine experiment

JohnSanders

Re: Results of a quick DEET--HCl-->Diethylamine experiment

Sedit

Re: Results of a quick DEET--HCl-->Diethylamine experiment

Sedit

Re: Results of a quick DEET--HCl-->Diethylamine experiment

heisenberg

Re: Results of a quick DEET--HCl-->Diethylamine experiment