Author Topic: Bromosafrole Made Easy  (Read 11937 times)

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Agent_Smith

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Re: Bromosafrole Made Easy
« Reply #60 on: April 28, 2001, 11:11:00 AM »
Well youre very right joe, by your equation.  I'm confused though about which equation is right...  I got mine, with the 1:1 ratio from webelements:

Post 186007 (missing)

(Rhodium: "Re: HBr bubbly bubbly", Chemistry Discourse)
and Rhodium shared:

"I don't think that the oil turning red is a sign of bromosafrole being formed (pure distilled bromosafrole is colorless), but rather a sign of safrole decomposition products being formed because acid is piped into it (HBr is known to break the methylenedioxy ring, and even if this reaction does not occur to a great extent if the reaction mixture is kept cool, the phenolic/quinone products formed from such a decomposition should be highly colored, so just a small amount of it will be visible in the solution). "

So which is the correct equation?  If joe is right, goddamn did I add to much sulfuric!!!

(by the way, I dunno what the hells going on with the experiment now.  The oil looks almost foamy, with an off-white appearance rather than the solid red it had before.  It still appears to be digested into sol'n very slowly.  If I did in fact use to much sulfuric, then the foamy oil is most likey decomposed safrole... shit)


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terbium

  • Guest
Re: Bromosafrole Made Easy
« Reply #61 on: April 28, 2001, 01:42:00 PM »

So which one is correct??  I'm beginning to think I'm missing something simple, someone just tell me which equation is right?


Either or both are correct.

Didn't you claim to understand pKa? Given the molar amounts of H2SO4 and KBr added to the aqueous solution and the pKas of H2SO4 and KBr you should be able to calculate the relative concentrations of each ionic species in the solution - H2SO4, HSO4-, SO42-, HBr and Br-.


foxy2

  • Guest
Re: Bromosafrole Made Easy
« Reply #62 on: April 28, 2001, 02:03:00 PM »
terbium
HBr is a strong acid and will completely disassociate in aqueous solution.

goiter
I doubt that the reaction goes all the way to the disodium salt

Agent Smith

Trisodium Phosphate (Na3PO4)+3H2SO4--->phosphoric acid and NaHSO4

Phosphoric acid + NaBr ---> NaH2PO4 (s) + HBr (g)

Simple/easy way to get HBr gas without Br2
Sould be a one pot shot, I doubt the salts will interfere much with the reaction.

This topic has gone on too long without good results.
If you must you can distill the acid at ~158C or lower temp with a """vacuum aspirator"""!!!

This topic is closed

:P  :P


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Agent_Smith

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Re: Bromosafrole Made Easy
« Reply #63 on: April 28, 2001, 03:12:00 PM »
Yes terbium, I understand pKa when applied to relative acid strengths, i.e. the relative amount of H+ in solution, however I don't fully understand how to apply it outside of a "which acid is stronger" situation.  Given my understanding or lack there of, how do I calc. how much H2SO4 to use since one equation is a 1:1 reactant ratio, whereas the other is 2:1

Foxy2, the reaction doesn't proceed all the way to the sodium salt?  Thus the thus the NaHSO4 equation is correct?  What conditions would cause it to go to the disodium salt?

(your one pot shot to H3PO4 would be great if I had trisodium phosphate)


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foxy2

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Re: Bromosafrole Made Easy
« Reply #64 on: April 28, 2001, 04:54:00 PM »
trisodium phosphate is easily avaiable at almost any paint/hardware store ect.  Look for something that says "TSP".  It is a common cleaner.  Discontinued in laundry detergent ect but still available for specialty cleaning ie washing walls to paint ect.  It is around!!!

I said it probably does not go to the disodium salt because HBr is a stronger acid than HNaSO4.  Which means only one Hydrogen is able to be utilized in produceing HBr.


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Agent_Smith

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Re: Bromosafrole Made Easy
« Reply #65 on: April 28, 2001, 05:23:00 PM »
I've done a lot of checking around in chem chatrooms and the like, and this is quite puzzling.

People tell me that this reaction can't be assumed to go to completion.  Due to psychological roadblocks and what not, I can't bring myself to understand how to calculate the correct amount of H2SO4 since there are multiple mechanisms that this reaction could follow, with different ratios.  I'll assume I need to measure pH over time and stop adding acid when i reach ideal pH.  So whats the ideal pH of 48% HBr sol'n?

AHA!!! By looking at other experimental procedures involving the production of HBr, like Drone's synth of Alkyl Halides (

http://rhodium.lycaeum.org/chemistry/drone/alkylhalides.html

) I find that some people are using a 1:2 ratio of NaBr to H2SO4 (this is different than both mine and joe's equations)!!!  Still others are using a 2:1 ratio of NaBr to H2SO4 like the DMSo writeup in

http://rhodium.lycaeum.ord/chemistry/halosafrole.txt

.  So I guess it's not horribly important, a 1:1 ratio is the best of both worlds, and should work fine, shouldn't it?  No matter what the precip. is, I don't think it matters, since the HBr used in the DMSO method and in drones method (even though Drone's isn't dealing with safrole) is not distilled and any Na2SO4 or NaHSO4 is left in. Yipee.


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foxy2

  • Guest
Re: Bromosafrole Made Easy
« Reply #66 on: April 28, 2001, 07:14:00 PM »
Shit
TSP is EASY to get!!!!!!!!!!!
Why use the fucked method that you are trying when it is so easy to get around it?????

I can't belive you are wasting so much effort thinking about this?

http://fry1.foxinternet.net/tips.htm


http://www.samallen.com/wwwboard/messages/8691.html


http://www.almanac.com/home/washthatsurface.html


http://www.shelfspace.com/~c-r-ffl/archives/199707/msg00473.html



Get out of the house and look around for TSP!




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smiley_boy

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Re: 48% HBr + P2O5
« Reply #67 on: April 28, 2001, 07:37:00 PM »
Rhodium,

Hey, that reminds me of another, sure-fire way of making gaseous HBr:

POBr3 + 3H2O -> H3PO4 + 3HBr

I'll be the first to admit that POBr3 is not cheap, nor is common. But it does look like a decent lab-prep for gaseous HBr. For the sake of thoroughness, I thought I'd add that in. ;)  You certainly can't disagree that this method would work, though its practicality "in the field" may be limited to those priveledged enough to have accounts with Sigma, et al.

smiley_boy

  • Guest
Re: Bromosafrole Made Easy
« Reply #68 on: April 28, 2001, 07:41:00 PM »
Thanks for taking the time to type that in. Yes Bwiti, that definately does appear to produce 48% HBr, and yes you're absolutely right that it won't be useful for making gaseous HBr.

Now about this business with HCl and H2SO4/NaBr, NaCl, etc. etc. etc. To tell you the truth, I can't see any of this working, though I'm trying really hard to stay open-minded. Do you have any solid reasons to justify a belief that any of those would work?

smiley_boy

  • Guest
Re: TSP and HBr
« Reply #69 on: April 28, 2001, 08:02:00 PM »
foxy2,

I disagree; this discussion should definately be continued. Yes my friend, I think we need a bit of a refresher course in pKa's. I did a quick ref search, and these are the numbers I got:

pKa HBr   = -8.6
pKa H2SO4 = -1.9
pKa H3PO4 =  2.18

From source to source, you'll find variances in the numbers, but the order will remain the same, phosphoric acid is far weaker than sulfuric acid, and sulfuric acid is weaker than hydrobromic acid. If you add TSP to sulfuric acid, sulfuric acid will most certainly liberate phosphoric acid. Let's look at the balanced reaction, shall we?

2Na3PO4 + 3H2SO4 -> 2H3PO4 +  3Na2SO4

Now, what you're proposing is this:

3NaBr + H3PO4 -> 3HBr + Na3PO4

Well, that's just not going to happen. That NaBr will sink to the bottom and sit there until doomsday. Phosphoric acid is just not going to liberate it, period. Feel free to prove me wrong; I'd really like to be.


trisodium phosphate is easily avaiable at almost any paint/hardware store ect.


Actually, TSP has been banned from a large number of river watersheds around the world, especially in North America.

Do you think that such a simple solution, if it were to exist, would have evaded the all-mighty Hive?(tm) Oh, the sheer hubris of you, my lad! I chuckle heartily at the very thought. BTW, what acid are you distilling at 158 C? We're talking about producing gaseous HBr, which has a boiling point of -66.8 C -- that's the goal here.

So at this point, we still have no procedure set out that we can point at and say: this is what everybody should use if gaseous HBr is what they want to make (though I think my suggestion using Br2 and NaBH4 comes pretty close.) Our goal isn't met, but I think if nothing else, this has been an educational dialogue.


foxy2

  • Guest
Re: TSP and HBr
« Reply #70 on: April 28, 2001, 08:44:00 PM »
Hey Smilely Dipshit

Learn some boiling points!!! they will help you in clandestine chemistry much more than fucking pKa's.
Phosphoric acid distills at 158C smarty ooops smilely.

TSP has been banned from laundry detergent and the like but it is still available as a specialty cleaner because it works so well.

See this link.  It is banned from household cleaners like laundry detergent and dishwasher soap but NOT for specialty applications. 

http://members.aol.com/StatutesP5/35.Cp.5D.html



Just start calling all the hardware stores in town, someone should have it.  If you are in a banned area call some in the next state.  I have seen it.




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foxy2

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Re: TSP and HBr
« Reply #71 on: April 28, 2001, 08:59:00 PM »
Hey Fuck Stick
"Now, what you're proposing is this:

3NaBr   H3PO4 -> 3HBr   Na3PO4

Well, that's just not going to happen. That NaBr will sink to the bottom and sit there until doomsday. Phosphoric acid is just not going to liberate it, period. Feel free to prove me wrong; I'd really like to be."

You ARE WRONG!!!!!!!!!!!
Stop trying to talk like a pro with your pKa shit.
I guess this chemistry prof has it all wrong in his tutorial he has online!!!!!!!
If you took the time to read this thread then you would have more of a clue than you do!!!
Time to take the free lesson at this link.
IT PROVES YOU WRONG

http://www.rscc.cc.tn.us/faculty/ward/1110/1110pdf/1110D07.pdf



Oh yea and one more thing fuck stick, H2SO4 is stronger than HBr




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goiterjoe

  • Guest
Re: TSP and HBr
« Reply #72 on: April 28, 2001, 10:24:00 PM »
I forgot all about the pKa of NaHSO4 being weaker than that of HBr.  thanks for reminding me.

as far as TSP goes, the brand name for as far as I can tell does not contain any actual TSP in north america.  maybe somewhere else they still sell it, but here they've determined it's pretty effective at killing fish and preventing them from reproducing.  I'd like to find some to take along with my dynamite to fish with at the next greenpeace rally.


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Agent_Smith

  • Guest
Re: TSP and HBr
« Reply #73 on: April 29, 2001, 12:59:00 AM »
Wow, calm down bees. 

foxy2, I liked the TSP idea very much, however I went out today and couldn't find it!  I found one product called "TSP-Aid" but on the back it said in bold "contains no TSP"  I'll look some more, I'm sure it's around.

Smiley_boy: the Hcl + NaBr stuff was crap, that was my idea, there are no refs to support it.  The H2SO4 + NaBr reaction is everywhere however, I've posted 4 or 5 references in this thread.  My problem is that I've seen the reaction proceed two different ways, and the balanced equations use 2 different ratios of reactant:

2NaBr + H2SO4 -> 2HBr + Na2SO4
or
NaBr + H2SO4 -> HBr + NaHSO4

I gather that bother reactions are correct, however, I don't know which one works in which case, probably both.  As such, since I used a 1:1 ratio of H2SO4 and NaBr, I don't know if I've used too much H2SO4 or not.

The excess H2SO4 is a problem because I'm dreaming right now, and I don't know if the excess H2SO4 in the HBr sol'n will destroy my sassy.  I know I should have distilled, but I no longer have any sort of controlled heat source so it's extrememly tedious to do. 

So now I have an HBr sol'n (that should be 48% or so if the reaction followed the NaBr + H2SO4 -> HBr + NaHSO4 mechanism), with sassy on top.  According to that J. Chromatography article I posted earlier, this should form bromosafrole if stirred at room temp for 7 days.

Is there excess H2SO4 in my sol'n?  Will it's presence destroy all my sassy, or does it act slow enough that I'll be ok?  My oil is now dark, although it foams very smooth when agitated like the foam on a nice glass of Guiness.  What do you think of this?



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terbium

  • Guest
Re: TSP and HBr
« Reply #74 on: April 29, 2001, 01:08:00 AM »

as far as TSP goes, the brand name for as far as I can tell does not contain any actual TSP in north america


Yes, for a long time I could no longer find real TriSodium Phosphate in hardware stores. There was a cleaner labeled TSP but it did not contain trisodium phosphate. Recently though I have been able to find real trisodium phosphate in hardware stores in Southern California.

It doesn't really, directly, kill fish or keep them from reproducing. The problem with phosphates is simply that they are fertilizers, essential for plant growth. Quantities of phosphates finding their way into bodies of water promote algal blooms. The algal blooms can then kill fish by consuming the available oxygen in the water.


smiley_boy

  • Guest
Re: TSP and HBr
« Reply #75 on: April 29, 2001, 06:52:00 AM »
Wow, somebody's entirely too upset!

If your arguements are that strong, I'd imagine you wouldn't need to resort to name-calling. Somehow the words 'fuck stick' just never struck me as something that I'd think would be a constructive contribution to a scientific discussion, but hey, I guess I don't know everything...


Learn some boiling points!!! they will help you in clandestine chemistry much more than fucking pKa's.



I'd have to disagree; pKa's and boiling points are both crucial in organic chemistry, depending on what a person is trying to accomplish. I really don't know what else to say to that.

Now that we have that troubled matter behind us, let's move on.

First, TSP and its availability. TSP has been banned not only from laundry detergents, but from a great deal of other places, too. As a matter of fact, a few months ago, when I needed to do some heavy-duty cleaning, I called the local hardware stores and found that they no longer carried it; in fact, it had been banned from hardware stores in my entire watershed, which occupies a fairly large chunk of the continent. I just thought you'd like to know.

As far as the tutorial online goes, this certainly is news to me. If this really works as it says, I'd like to thank you for pointing it out to me. This really is remarkable; I've looked through more secondary and tertiary literature sources for preparations of HBr gas than I care to mention, but never was this outlined. We still don't have anything resembling a set procedure, but its nice to think that this might work.

Now finally, I'd like to talk to you about your last misunderstanding.

Quote
Oh yea and one more thing fuck stick, H2SO4 is stronger than HBr
Quote


I stand by my original statement. Somehow, I remain unconvinced, despite your clever use of the term 'fuck stick'. Please, look at the pKa numbers given above, and explain to me how sulfuric acid is stronger than hydrobromic acid. I thought it was pretty straight-forward, but perhaps not.


foxy2

  • Guest
Re: TSP and HBr
« Reply #76 on: April 29, 2001, 02:25:00 PM »
Well i was having a bad day and ******* (i won't say it) pisses me off.   Your pKa values have absolutely NO impact on this discussion.  pKa vales apply to dilute aqueaous solutions which we are NOT talking about.  A different measure of acid strength is necessary.  One that defines the strength based on the force of attraction for a counter ion, not pKa.  Read this short description of what I mean.  pKa measures an acids dissociation in water, that is not necessarily the same as its strength of attraction of a counter ion.  Time to sign up for a few more classes, actually it sounds like those classes hurt you more than they helped.

Here is an online discussion that illustrates my point, I didn't do a good job of making my case earlier however I knew I was right.


Question:  What is the strongest acid?
How do you distinguish between two acids that are both 100% dissociated?
 jim day

Answer:
Interesting question there...the strongest acids are sometimes
referred to as "superacids." These have an extremely large
proton-donating ability.  Usually an acid is considered to
be a superacid if it has a proton-donating ability greater
than / equal to that of 1nhydrous (100%) sulfuric acid.
 
Apparently the strongest acid is hydrogen flouride (HF).
 
Upon reading, it seems that it is actually tough to distinguish
between the superacids on the basis of their pH alone. All strong
acids are fully ionized in dilute solution, and therefore they
all appear to have the same strength, equal to that of the
hydronium ion (h3O+), which is the most highly acidic species
that can exist in water. So all of these have the same pH on a
per-proton basis.
 
So, to rank superacids, chemists measure how strongly they tend to
react with a given base, B;
HA + B --> BH+ + A
 
This way, even superacids can be ranked relative to one another
in terms of their "strength." HF is the strongest in the table I
am looking at, followed by HSO3F, H2S2O7, HSO3CF3, HSO3Cl,
and H2SO4 (sulfuric acid).
All my data is from the McGraw-Hill Encyclopedia of Sci/Tech. -topper

Question:  You say that Hydrofluoric acid (HF) is the strongest acid.  However, from
what I understand its not even a super acid meaning it doesn't ionize 100%.
When I looked up the Ka value for it it was said to be 3.53X10^-4
(according to the CRC hand book of chemistry and physics) giving it a pH
of 1.73 and a %ionization of 1.8%. How can this be the strongest acid?

Different scales of acidity can give different rankings.  It's all a matter
of what is being measured.  It is true that HF does not fully dissociate in
water unless you add a base to it.  (Incidentally, a "superacid" can be
defined in several ways;  I have never before heard 100% dissociation as one
of them.  The two definitions I have heard are 1.  more acidic than
anhydrous AlCl3, and 2.  more acidic than concentrated H2SO4.) Anhydrous HF,
however, is considered one of the most acidic substances known.  This means
that it readily protonates other reference bases, even though it does not
extensively dissociate in water.

Why is this?  I don't know.  I imagine that it might have something to do
with hydration preferentially stabilizing HF over H+ + F-.  Indirect
measurements indicate that HF is much better hydrated than any of the other
hydrogen halides.  This fact alone will make it less ionized in aqueous
solution.  The fact that anhydrous HF exists as hydrogen-bonded polymers
probably also has something to do with it.

Richard E. Barrans Jr., Ph.D.
Assistant Director
PG Research Foundation, Darien, Illinois

=========================================================

Dear Ivan,

Upon rereading that answer I wrote long long ago,
I see that I made at least one error. I said that
"all strong acids are fully ionized in dilute solution."
This is much too strong a statement. There is in reality
a continuum of behaviors as one goes from weak acids
to strong acids. And many strong acids, HF being
one of them, are not 100% dissociated in aqueous solution
(although one tends to treat them that way as a first
approximation).

As I tried to explain in the message you referred to,
it is my understanding (although I could be mistaken) that
one cannot correlate the reactivity of a strong acid
with its Ka value. Weak acids can indeed be so
correlated, but not strong ones. This is, as I mentioned,
due to the fact that no acid in aqueous solution can have
a greater Arrhenius acidity than H3O+. Therefore,
one ranks the strength of strong acids according
not to the Arrhenius definition (tendency to
dissociate in aqueous solution) but according to the
Bronsted-Lowry definition (tendency to transfer a proton
to a given base in an acid-base reaction).

A superacid is not one which is 100% dissociated
but one which has a tendency to undergo BL acid-base
reactions more readily than anhydrous sulfuric acid
(this is, I believe, the IUPAC definition, but again
I could be mistaken).
I hope this helps. I suggest you consult the same primary
reference I consulted, i.e., the McGraw-Hill Encyclopedia
of Science and Technology.
Best regards,
prof. topper
dept of chemistry
the cooper union
new york, ny


Links

http://newton.dep.anl.gov/askasci/chem99/chem99182.htm


http://newton.dep.anl.gov/askasci/chem99/chem99669.htm



Fuckstick (take it as a term of endearment)
Now lets see a responce with something to back up what you have to say instead of pKa this and pKa that.

:P  :P  :P


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goiterjoe

  • Guest
Re: TSP and HBr
« Reply #77 on: April 29, 2001, 03:42:00 PM »
what, are you going to make flourosafrole now?  do you think your glass will handle that one?  maybe instead of bullshitting about who knows what and which method of ranking you should use for acid strength, why not just post the rankings of sulfuric and HBr in the presence of a base, which was the original delimna anyway?  then you could decide once and for all who was correct.  this pissing contest you have going on is making a nasty mess of a thread that used to be very interesting.


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foxy2

  • Guest
Re: TSP and HBr
« Reply #78 on: April 29, 2001, 04:11:00 PM »
Yea Fluorosaf now wouldn't that bee fun, and good for the teeth and bones too!!!!

I thought it was obvious that H2SO4 has a stronger affinity otherwise you would not get HBr/Br2 when you combine H2SO4 and NaBr.  Hey goiter, sorry about the ranting and raveing, but there are a few good lessons in between it all (as long as you don't read any of smellys posts).  This post was actually knd of dry at the start tho, it was try after try of a method that fails.  Try it this way try it that way, while i admire the experimental attempts, sometimes you need to take the blinders off and look for a new way.

Hope i didn't hurt any feelings
:P  :P  :P

hehehehe


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Agent_Smith

  • Guest
Re: TSP and HBr
« Reply #79 on: April 29, 2001, 06:52:00 PM »
Thanks to foxy and smiley_boy for that exchange, it was informative to me at least.  What of this puppy I've got brewing here then?  It's sassy sitting in a sol'n of HBr and an unknown amount of unreacted H2SO4, along with some SO4 salt (me thinks the salt is inconsequential).  How much will that unknown concentration of H2SO4 fuck things up?

My reasoning is that it shouldn't matter, and that decomposition from the H2SO4 isn't that big of a deal.  Many bromosafrole texts report yields above 95%, even though the HBr used (applied in many different forms) is known to break down the safrole in a similar fashion as H2SO4.

R.e. the futility of this method:  I don't think it should be dismissed because it hasn't worked on the first few tries.  Many references support whats trying to be done, its not like were pulling this out of our asses.  There are methods even more cryptic than this one (pseudonitrosite?) that don't get the flame fest.

R.e. H3PO4, I've heard of this reaction many time, and tried it with NaI, however it's not as cut and dried as you think.  It often requires heating to begin, and most of the time, I can't make it go at all.  I'm not the only one:

Post 10334 (missing)

(Biscuit2: "Re: Halosaf via DMSO not working, NMR data to proove", Methods Discourse)
  Regardless, I shall deal with this later, what of the reaction I have in progress?

Also, if someone has time, check this out and tell me wtf he is talking about:

Post 9583 (missing)

(Chopper_: "Re: Halosaf via DMSO not working, NMR data to proove", Methods Discourse)
,

Post 9993 (missing)

(Chopper_: "Re: Halosaf via DMSO not working, NMR data to proove", Methods Discourse)



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