Sciencemadness Discussion Board

Oh crap

Unfeigned Indifference - 17-6-2010 at 06:05

Yes a brillant first post but whatcha gonna do and not sure where it should go, so hopefully I get at least this one right.

Some time ago a simple hydrolysis of C10H12O2 was attempted. A small amount of the compound circa 300ml was refluxed with ETOH and KOH or at least so I thought. Truth of the matter is shortly after treatment with H2SO4 it was realized that KOH was not used. Instead C10H12O2 was refluxed under NaNO3? Yes, I am sure this has never happened to anyone before but being that one had never worked with KOH before he had not even thought to think the appearance of NaNO3 strange as he had worked plenty with NaOH and both are somewhat grandular in form or at least NaOH can be. KOH when he has pulled it off the shelf in unmistakably looks like little arrow heads and not grandular so he realized that he indeed used the other large white bottle which is NaNO3.

I am pretty sure a) there is no such compound as phenylethyl nitrate and b) that the conditions were not in place to even broach on nitration of this compound, yet odd as it may seem after treatment with H2SO4, there was substantial formation of a white precipitate which was then filtered, recrystallized and put away alongside other to-be-reviewed at some other time disasters that always keeps me busy when time permits. But exactly what did I do? And is it useful for anything under the sun, can it be undone, or should it be discarded? I have a tendency to desire utilizing spare parts if they can be salvaged, example is an old Nicodem post on eggshells and harvesting CaCO3, from that I am able to get the chloride, oxide, and what not. Though simplier means exist I enjoy doing it and would like to salvage this mess if possible, but then again this is not such a simple compound either now is it, eggshells I would assume would entail a much simplier explanation as to it's existance if ever questioned that much I do know. Any help would be appreciated.

mr.crow - 17-6-2010 at 06:39

Welcome to the forum

What is C10H12O2? Thats not how we name organic compounds, it could be many different things.

KOH and NaNO3 are completely different, probably no reaction occurred. You can filter it out or re-distill it.

Wizzard - 17-6-2010 at 12:35

I think it's an aromatic chemical :) Maybe an extract?

psychokinetic - 17-6-2010 at 13:00

Quote: Originally posted by Unfeigned Indifference  

I am pretty sure a) there is no such compound as phenylethyl nitrate


I beg to differ.

Sedit - 17-6-2010 at 14:05

Am I the only person to get really annoyed when someone writes a complex organic structure out as CxOxHx. I can sit back and dray a whole lot of isomers with that right there.

not_important - 17-6-2010 at 17:40

Well, at least they just did give an integer value MW instead. But it is a bit of a guessing game, and I'm lazy enough to not bother figuring out that they are talking about 2-phenylethanol acetate, given the intended alkaline hydrolysis, because eugenol would not be giving phenethyl anything. They must have a drum of it, because 300 ml was referred to as "a small amount". I am at a loss as to what "grandular" means. Glandular? Too much self importance "he was very grandular today"? Something to do with one's parents' parents?

I would have extracted the aqueous with toluene several times, then evaporated off the toluene, if indeed it was that fruity-floral scented ester.



Unfeigned Indifference - 18-6-2010 at 21:40

Quote: Originally posted by mr.crow  
Welcome to the forum

What is C10H12O2? Thats not how we name organic compounds, it could be many different things.

KOH and NaNO3 are completely different, probably no reaction occurred. You can filter it out or re-distill it.


Thanks for the welcome, and yes I understand both are completely different but not having worked with KOH in the past and letting my guard down led to this blunder. Most of my reagents are in glass bottles so in regards to glass items, it's become a force of habit to make sure I grab the right one. White plastic jugs type things are a rarity.

The compound in question is C6H5CH2COOC2H5 apologies for the confusion.
Quote: Originally posted by Wizzard  
I think it's an aromatic chemical :) Maybe an extract?


You may be very right, one thing is for certain and that is it may be worth discarding just to get rid of that horrible smell. :o
Quote: Originally posted by psychokinetic  


I beg to differ.


??? Please explain, now granted it appeared that a great deal of NO3 dissolution was achieved utilizing ETOH as a solvent(inadvertently), but was that enough to nitrate this compound? If so, why is it difficult to find supporting material on this?
Quote: Originally posted by Sedit  
Am I the only person to get really annoyed when someone writes a complex organic structure out as CxOxHx.


Again my apologies for the confusion, it can be problematic when someone is unable to understand what you are saying hopefully I have cleared this up.
Quote: Originally posted by Sedit  
I can sit back and dray a whole lot of isomers with that right there.


"dray"??? I guess we both have something to work on :) So with my having made the needed corrections and your knowledge over things such as isomers, then if it's alright by you. What could be the proper way of correcting this, other than reading the bottle next time? Something occured as the combination of both H2SO4 and NaNO3 would not leave behind any soluble product on it's own, all possible byproduct(s) from their direct interaction would be soluble, correct? So please explain the resulting precipitation?
Quote: Originally posted by not_important  
Well, at least they just did give an integer value MW instead. But it is a bit of a guessing game, and I'm lazy enough to not bother figuring out that they are talking about 2-phenylethanol acetate, given the intended alkaline hydrolysis, because eugenol would not be giving phenethyl anything. They must have a drum of it, because 300 ml was referred to as "a small amount". I am at a loss as to what "grandular" means. Glandular? Too much self importance "he was very grandular today"? Something to do with one's parents' parents?

I would have extracted the aqueous with toluene several times, then evaporated off the toluene, if indeed it was that fruity-floral scented ester.





sorry again, "granular" seems to have a "d" in there that did not belong whereas KOH, well you of all people don't need an explanation on that one. :) Again its that whole trying to get a thought out in limited time and not proofreading it first. Thanks for the observations and I thought of doing something along those lines(extraction of the aqueous) but this concerns me:

NaNO3 +H2SO4 --> Na(+)+ +NO3(-) +2H(+) +SO4(2-)

and that is prior to any potential interactions with the compound itself. Would not continuing with an extraction of the aqueous also run the risk of bringing in any impurities along with it, not that it could mess things up any worse than it already is. Also why would the aqueous layer be of concern if noticeable precipitate was generated after titration? Would this not run contrary to the above equation since if precipation could not be generated from the combination of NaNO3+H2SO4, then it would appear that the precipitate could find it's roots in some type of interaction with the actual aromatic compound in question? Is precipitation to be expected after a NaNO3 has been treated with sulfuric acid? and if so then the above equation would be false? It was observed that the resulting precipitate once filtered, recrystallized from hot DH2O(3 times), filtered, and then placed into a dessicator over CaCI2 for several days came out still smelling strongly of the aromatic, why?



[Edited on 19-6-2010 by Unfeigned Indifference]

[Edited on 19-6-2010 by Unfeigned Indifference]

not_important - 18-6-2010 at 23:01

Missing is a certain amount of detail
Quote:
A "small" amount of the compound circa 300ml was refluxed with ETOH and KOH
... shortly after treatment with H2SO4 ...


How much EtOH and NaNO3? How much H2SO4, and of what strength? It sounds as if you were tracking the pH, so there should have been not been a lot of free H2SO4 to start with. While we're at it, what is the pH of a water solution of the NaNO3?
Quote:
...there was substantial formation of a white precipitate which was then filtered, recrystallized ...


Recrystallised from what? It makes a difference if the solvent was VOCl3, N2O4, L<sup>3</sup>He, SCCO2, or whatever. At what temperature? Was it water, as implied later?

Both the original compound and the expected product are liquids, sort of counts them out. Most derived organic compounds probability depends on the answers to the above questions. Inorganics include NaNO3, NaHSO4, and Na2SO4.

That organic family is fairly odoriferous, and slightly soluble in water, it might contaminate an inorganic salt. I'd heat a smallish fraction of a gram in an old spoon and see what happens. Something basically inorganic will act much different than an organic, hydrated sodium sulfate will 'melt' and the dehydrate to do nothing interesting until really toasty hot. NaHSO4 will melt at around 60 C then dehydrate, melting again above 300 C as it further dehydrates to the pyrosulfate which melts around 400 C and soon begins to give off SO3. NaNO3 melts a tad above 300C, sticking the tip of a splinter or straw into it will make it obvious it's the nitrate vs a sulfate..


The phenylethanol would be about as easy to nitrate as toluene, just a bit less active. Anything above mononitration would not be expected You could check the descriptions of those, I suspect they are pale yellow liquids although the p- isomer might be solid. If the H2SO4 was strong enough, and enough was added, it is just possible some of the ester was nitrated, but right now I am doubtful.

--------------------------------

Adding NaHCO3 _slowly_ would have taken care of free acids without bringing about (further) hydrolysis of the ester. Adding NaCl to saturation, followed by extraction, would have recovered ester and alcohol along with some EtOH, and any nitrate ester of that. Back extracting with a little water would remove much of the EtOH.

It appears that one more missing item is "did you separate organic and aqueous layers, and how much water was there - going back to the H2SO4 strength but also asking if you added water. If the proportion of EtOH was high, no or little water added, then organics would dissolve in its layer and inorganic salts ppt.



[Edited on 19-6-2010 by not_important]

DJF90 - 18-6-2010 at 23:47

not_important: He's not doing a reduction so phenylethanol cannot be the product given the structural formula he provides. What he mentions is ethyl phenylacetate, which on hydrolysis will give phenylacetic acid. A mixture of NaNO3 and H2SO4 should afford nitration.

not_important - 19-6-2010 at 00:19

I'm going by " phenylethyl nitrate " which could form from phenylethanol, the acetate of which is a high volume scent chemical. If it's the corresponding acid then, yes it is a solid and smells strongly and distinctly, and would ppt from solution if enough water was added. But its nitration is less likely than that of the alcohol, as the -CO2 slightly lowers the activating effect of the benzylic carbon. So a bit more difficult to nitrate than toluene, a slightly proportion of para and meta substitution than toluene If by 'titrate' it is meant 'add acid while watching the pH' then little H2SO4 should have been added meaning little nitration expected. If titrate means 'dump in as much acid as I calculated would be needed' then it's another story.

And in that case I believe the mononitrates are pale yellow, form crystals well from water, and have melting points in the 140-155 C range vs ... 75? for the original acid. It would be easy to look up the melting points and do a check on the sample.

psychokinetic - 19-6-2010 at 04:20

You said it didn't exit, not just that you didn't make it.

Panache - 27-6-2010 at 13:04

Quote: Originally posted by psychokinetic  
You said it didn't exit, not just that you didn't make it.


so if it didn't exit it must still be in there right?:P:P