| Pages:
1
..
10
11
12
13
14
..
30 |
Formula409
Hazard to Others
Posts: 129
Registered: 13-12-2008
Member Is Offline
Mood: No Mood
|
|
Does anybody know a synthesis for 3-methoxy-4-halobenzaldehyde from reasonably common materials? I thought it would be a simple case of bromination of
Vanillin. I was mistaken.
Formula409.
|
|
|
sonogashira
National Hazard
Posts: 555
Registered: 10-9-2006
Member Is Offline
Mood: No Mood
|
|
Hi, I have a possibly very silly question but i will ask anyway - with slight shame: 
Is it possible to convert a primary amine hydrochloride to an amine acetate by adding glacial acetic acid and distilling?
I hope that the HCl will fly away and be left with the acetate salt. Has anyone
done this?
The problem with the compound is that is very unstable in base. The acetate salt can be recrystallized and therefore purified; but this is not
possible with the HCl which is the product of the last step- hence the need to convert in acidic conditions.
Thanks for any wisdom!!
[Edited on 2-8-2009 by sonogashira]
|
|
|
12AX7
Post Harlot
Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline
Mood: informative
|
|
The pH is never even low enough to form HCl, let alone enough to evaporate.
Ion exchange sounds like a better idea. Load resin with acetate, flush, voila, no more chloride.
Tim
|
|
|
sonogashira
National Hazard
Posts: 555
Registered: 10-9-2006
Member Is Offline
Mood: No Mood
|
|
But maybe with a large excess it will push the equilibrium in the correct direction- do you think?
I know pH is against me but I wonder if the large excess could save the day 
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
Just do a salt metathesis with a few % excess of anhydrous sodium or potassium acetate in ethanol. Stir and slightly heat for some time, cool, filter
of the NaCl/KCl precipitate and concentrate. The product might not be cleanly acetate and there will be some Na/K chlorides left (their solubility in
ethanol is not negligible!), but at least it is simple enough (provided the acetate is soluble in ethanol like it is usually the case with most amine
acetates that are large enough).
|
|
|
sonogashira
National Hazard
Posts: 555
Registered: 10-9-2006
Member Is Offline
Mood: No Mood
|
|
Thanks, i'll try that. I just thought that perhaps silver acetate in dilute acetic acid could be used also - but i'll have look into that. Thanks for
the guidance!
[Edited on 2-8-2009 by sonogashira]
|
|
|
Klute
International Hazard
Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline
Mood: No Mood
|
|
Why not just freebase the hydrochloride and titrate with GAA?
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
|
|
|
12AX7
Post Harlot
Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline
Mood: informative
|
|
Oh, as precipitation goes, lead acetate would be nearly as complete as silver acetate, and quite a bit cheaper (and photostable!).
Klute:
| Quote: | | The problem with the compound is that is very unstable in base. |
Tim
|
|
|
Picric-A
National Hazard
Posts: 796
Registered: 1-5-2008
Location: England
Member Is Offline
Mood: Fuming
|
|
As i dont have access to references anymore i will post this here.
Does anybody have access to this article?;
http://pubs.acs.org/doi/abs/10.1021/ie50532a036
thanks
|
|
|
sonogashira
National Hazard
Posts: 555
Registered: 10-9-2006
Member Is Offline
Mood: No Mood
|
|
Thank you for that information also Tim, i did not know that lead salts could be used too.
I have tried several small tests from the procedures recommended, and the products are now crystallizing overnightI think all will go well and i will
chose the one which gives best yield for the bulk of the product.
Thank you for all the help- and best wishes
Here you go Mr Picric Acid:
Attachment: picric.pdf (574kB)
This file has been downloaded 3282 times
|
|
|
Picric-A
National Hazard
Posts: 796
Registered: 1-5-2008
Location: England
Member Is Offline
Mood: Fuming
|
|
@sonogashira - Sweet! thanks for your help m8!
|
|
|
itchyfruit
Hazard to Others
Posts: 231
Registered: 15-6-2009
Member Is Offline
Mood: No Mood
|
|
Frozen Acetic acid
I've just realised that putting my acetic acid in the fridge was not a good idea, it's frozen solid, will it be ok if i just defrost it or have i
ruined it?
I know i'm stupid, but i now know that acetic acid freezes at 16oc so i have learnt something!!!
|
|
|
DJF90
International Hazard
Posts: 2266
Registered: 15-12-2007
Location: At the bench
Member Is Offline
Mood: No Mood
|
|
just leave it to defrost and it'll be back to normal.
|
|
|
itchyfruit
Hazard to Others
Posts: 231
Registered: 15-6-2009
Member Is Offline
Mood: No Mood
|
|
Cool, Thanks
|
|
|
Jor
National Hazard
Posts: 950
Registered: 21-11-2007
Member Is Offline
Mood: No Mood
|
|
My acetic acid is always frozen during the entire winter!
It's really beautiful to see the huge mass of crystals.
Once, it was far below 16C and the acetic ascid was still not frozen. This was because for something to crystallise, you need a nucleation point
(thats what its called right?), and when the bottle is standing completely still that is not present. But then I picked up the bottle and shook it.
The effect was beautiful, a liter of acetic acid crystallising in a few seconds.
If you want to store your acetic, even in the cold, add a little water. 100% AcOH freezes at 16C, 96% at 10C, etc. I store a small bottle of 80% AcOh
during winter, and that doesn't freeze.
|
|
|
itchyfruit
Hazard to Others
Posts: 231
Registered: 15-6-2009
Member Is Offline
Mood: No Mood
|
|
Weirdly, i just assumed that it wouldn't freeze until below 0oc but then what do i know,and we all know what they say about assumption
|
|
|
gnitseretni
Hazard to Others
Posts: 282
Registered: 5-1-2007
Location: Colombia
Member Is Offline
Mood: No Mood
|
|
Does anyone know what, besides fuel, you could use powdered hexamine for on a camping trip?
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
Well, if you bruise yourself while setting the tend, you can always use its aqueous solution as antiseptic.
You can also use it as repellent for bears if you thermolyse it on a hot pan. I doubt it would be very effective though.
|
|
|
gnitseretni
Hazard to Others
Posts: 282
Registered: 5-1-2007
Location: Colombia
Member Is Offline
Mood: No Mood
|
|
antiseptic huh. What if, while performing hydrolysis, i held a wet cloth above it to absorb the formaldehyde vapor.. would that make for an even
better antiseptic?
|
|
|
Rich_Insane
Hazard to Others
Posts: 371
Registered: 24-4-2009
Location: Portland, Oregon
Member Is Offline
Mood: alive
|
|
Isn't formaldehyde carcinogenic?
I think that would work, as I believe it is used as a source of formaldehyde.
|
|
|
Formula409
Hazard to Others
Posts: 129
Registered: 13-12-2008
Member Is Offline
Mood: No Mood
|
|
Can Benzyl Iodide be made by iodinating toluene with molecular iodine under UV like how benzyl chloride and bromide can be made?
Formula409.
|
|
|
solo
International Hazard
Posts: 3975
Registered: 9-12-2002
Location: Estados Unidos de La Republica Mexicana
Member Is Offline
Mood: ....getting old and drowning in a sea of knowledge
|
|
I can't find what this compound is it called ......is it 2 chloro- benzyl propane.....?
C6H5CH2CH(Cl)CH3....as i'm interested in doing a Finklestein swap with bromine
..................solo
[Edited on 9-8-2009 by solo]
It's better to die on your feet, than live on your knees....Emiliano Zapata.
|
|
|
sparkgap
International Hazard
Posts: 1234
Registered: 16-1-2005
Location: not where you think
Member Is Offline
Mood: chaotropic
|
|
I'd call that 2-chloro-1-phenylpropane, solo.
sparky (~_~)
"What's UTFSE? I keep hearing about it, but I can't be arsed to search for the answer..."
|
|
|
Sedit
International Hazard
Posts: 1939
Registered: 23-11-2008
Member Is Offline
Mood: Manic Expressive
|
|
You can also name it 2-chloropropyl benzene if you like. The Finklestein should proceed smoothly with this compound.
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by Formula409  | | Can Benzyl Iodide be made by iodinating toluene with molecular iodine under UV like how benzyl chloride and bromide can be made?
|
Most probably no and almost certainly not with I2 for what I know, but I have not checked the literature so don't take my word for granted. Benzyl
iodide is a photolabile compound anyway.
Besides in the radical halogenation of toluene with either chlorine or bromine you do not use UV light as this is too inefficient, visible light is
used - direct sunlight for example, or a strong halogen or mercury lamp, even a normal incandescent lamp works to some degree. Blue light (energy
maximum at about 425 nm) gives a higher rate of chlorination than ultraviolet (about 370 nm) because it more effectively penetrates a solution
containing free chlorine. (cited from Kirk-Othmer's chapter on benzyl chloride production) See Len's prepublication on the topic.
| Quote: | I can't find what this compound is it called ......is it 2 chloro- benzyl propane.....?
C6H5CH2CH(Cl)CH3....as i'm interested in doing a Finklestein swap with bromine |
The Finklestein reaction using the normal protocol (NaI in refluxing acetone) is terribly slow on secondary alkyl chlorides like this one. It would
probably work, but it might take a couple of days reflux. In any case you would need to monitor the reaction progress anyway.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
|
|
|
| Pages:
1
..
10
11
12
13
14
..
30 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
