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[*] posted on 5-7-2016 at 16:44
acetol from sugar


how would you synthesis acetol from sugar
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[*] posted on 6-7-2016 at 08:44


Quote: Originally posted by madscience  
how would you synthesis acetol from sugar

Depends what sugar...
If normal table sugar; then if by acetol, you mean hydroxyaceton (1-hydroxy-propanone) ...
you may get a chance to go there from:
1)sugar alcoholic fermentation --> ethanol -oxydation-> acetic acid
2)sugar acetic fermentation --> acetic acid
3)making aceton from acetic acid (Ca acetate or Ba acetate pyrolysis...CaCO3 or BaCO3 recoverable and recycled with acetic acid)
4) sugar fermentation direct to aceton
5) aceton monohalogenation (Cl2 or Br2 in HCl or HBr) beware of the lachrymatory product (a wargas)--> Under the Hood
6) hydrolysis in neutral media to avoid as much polycondensation into resinous polyphénols

Not chemistry for a beginner!
Much easier to start directly from aceton...




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[*] posted on 10-7-2016 at 05:03


I have an emulsion of water and isobutyl bromide. What would be the best way to break it up? I was thinking of adding some salt or sulfuric acid, but I don't want to screw it up.

Side question: Does anyone know what isobutyl bromide smells like? I can't find any description of it, but my product smells butterscotch-like, kind of along the lines of MEK but heavier and sweeter.

Edit: Never mind the thing about the emulsion, it cleared itself up after resting for a few minutes.

[Edited on 7-10-2016 by zts16]




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[*] posted on 10-7-2016 at 10:51


Can 2% MEK in ethanol be polymerized or otherwise converted to a more stable form for ethanol purification with NaOH?
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[*] posted on 10-7-2016 at 14:49


Quote: Originally posted by Refinery  
Can 2% MEK in ethanol be polymerized or otherwise converted to a more stable form for ethanol purification with NaOH?

Might work!
Butanone (MEK) may be subject to aldolisation-crotonisation thus yielding higher molecular weight molecules, less volatile and remaining in the flask with the NaOH during the distillation of Ethanol.




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[*] posted on 10-7-2016 at 23:23


Only way to find it out is to test it, then.
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thumbup.gif posted on 11-7-2016 at 07:37
Haloform Reaction Question.


Greetings,
I carried out a haloform reaction between a solution of 5% sodium hypochlorite and acetone earlier today and I only used a 5% excess of bleach. Unlike my previous run that has a very pale greenish yellow, the end solution of this run was completely colourless. Hence I was wondering if it would be useful if I mix all my chloroform into 1L of bleach just to ensure all acetone has reacted and to avoid having to deal with the annoying azeotrope between acetone and chloroform before distilling my chloroform.
Thanks in advance!




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[*] posted on 19-7-2016 at 02:15
leuckart reaction and formate salts


Would the salt of formic acid work in the leuckart reaction like sodium formate and potassium formate, and would it reduce the imine if you react aldehyde or ketone with a amine with formate salt as the reducing agent and would still form the n formyl impurities the reason I ask im trying to make alanine

[Edited on 19-7-2016 by madscience]
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[*] posted on 19-7-2016 at 12:22


No. The use of ammonium formate is critical for the synthesis of an amine. Without the ammonium cation, it is impossible to form the hemiaminal which is reduced to the final amine product. By the way, could you elaborate on what you mean by "reduce impurities"? What sort of impurities are you referring to?



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[*] posted on 19-7-2016 at 13:53
Test for guanidine nitrate


We made some (hopefully) guanidine nitrate by following the procedure in this thread http://www.sciencemadness.org/talk/viewthread.php?tid=12938

Things got a bit out of hand near the end, so we're not sure If we actually have guanidine nitrate. Here's what we've got:

IMG_3257[1].JPG - 2.3MB

Is there any test for guanidine nitrate that would distinguish it from ammonium nitrate and urea?
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[*] posted on 19-7-2016 at 16:22
Question – Is it really a catalyst?


I have been thinking about a couple of well-known reactions.

First, Fischer esterification in which the added H2SO4 is often stated to be a catalyst. I am questioning this. It seems to me that its role is to push the equilibrium to the right rather than to catalyse. Sulfuric acid provides for an acidic environment and also absorbs water: both of which favour the formation of products. Is there any catalysis occurring also?

Second, the lovely Chameleon reaction demonstration of the oxidation states of manganese using (typically) sucrose. NaOH is added, purportedly as a catalyst. But it seems a strange chemical for a catalyst in my limited experience. And I cannot really figure out what its role is. I'd love some enlightenment.

(I bet blogfast25 knows. But we have seen less of him lately.)




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[*] posted on 19-7-2016 at 19:44


j-sum1:

Sulfuric acid is a catalyst in the Fischer esterification. It is chemically unchanged in the reaction. With some effort, you could isolate all of the H2SO4 that you started with at the end of the reaction which by definition makes it a catalyst. Mechanistically, the H2SO4 reacts with the carboxylic acid function to form a transient acylium ion which reacts with the alcohol to form the ester via a follow-on elimination of water. No water is "absorbed." Any good O-chem book should illustrate this mechanism.

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[*] posted on 19-7-2016 at 21:16


Quote: Originally posted by AvBaeyer  
j-sum1:

Sulfuric acid is a catalyst in the Fischer esterification. It is chemically unchanged in the reaction. With some effort, you could isolate all of the H2SO4 that you started with at the end of the reaction which by definition makes it a catalyst. Mechanistically, the H2SO4 reacts with the carboxylic acid function to form a transient acylium ion which reacts with the alcohol to form the ester via a follow-on elimination of water. No water is "absorbed." Any good O-chem book should illustrate this mechanism.

AvB

Thanks AvB.
I am yet to read a good O-Chem book. Long story.

So what is happening with the NaOH and the Mn reduction?




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[*] posted on 20-7-2016 at 03:40


Can i dissolve Palladium powder in HCl (>30%) / H2O2 (~30%) to make PdCl2?
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[*] posted on 21-7-2016 at 00:44
copper-glycerol complex


I made this complex https://upload.wikimedia.org/wikipedia/commons/0/00/Glycerol...

I added some glycerol to a suspension of copper(ii) hydroxide in dilute sodium hydroxide solution and ended up with a beautiful solution of the complex.

My question is, how can I isolate the complex from this solution?

Will adding ethanol make the complex precipitate?




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[*] posted on 21-7-2016 at 12:30
which functional group would aminate first


which of this functional groups would aminate first a benzoyl or an acetyl group if you do a reductive amination on these groups
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[*] posted on 22-7-2016 at 12:29


Quote: Originally posted by dawsonsuen  
Greetings,
I carried out a haloform reaction between a solution of 5% sodium hypochlorite and acetone earlier today and I only used a 5% excess of bleach. Unlike my previous run that has a very pale greenish yellow, the end solution of this run was completely colourless. Hence I was wondering if it would be useful if I mix all my chloroform into 1L of bleach just to ensure all acetone has reacted and to avoid having to deal with the annoying azeotrope between acetone and chloroform before distilling my chloroform.
Thanks in advance!

From what I recall, the reaction runs various colors based on bleach quality/source. Watch chemplayer's synthesis of chlorobutanol to see if the reaction ran more like that preparation and the chlorobutanol sideproduct was formed due to excess acetone.




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[*] posted on 23-7-2016 at 17:10
Distillation setup - 500ml vs 1L - can they be interchanged with vessel size?


I see 500ml and 1L setups advertised and price may be double for the 1L. Are general distillation (no columns - just boiling flask, riser from flask, condenser & receiving vessel) setups capable of just changing the vessel size but still using the same condenser and riser (assuming same joint size)?
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[*] posted on 23-7-2016 at 17:18


Yes
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[*] posted on 24-7-2016 at 20:02
MonoAmmonium Phosphate vs DiAmmonium Phosphate as yeast nutrient/energizer


I have seen a lot of yeast nutrients/energizers that contain DAP and I have also seen some that have ammonium sulfate in place of DAP. From what I have read the reason for putting these in with the yeast is to provide nitrogen to the yeast. My question is whether MAP can be used instead of DAP (with adjustments for the fact MAP has 1/2 the N as DAP). Also is there any reason that DAP is better than ammonium sulfate?
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[*] posted on 25-7-2016 at 03:59


Quote: Originally posted by j_sum1  

Second, the lovely Chameleon reaction demonstration of the oxidation states of manganese using (typically) sucrose. NaOH is added, purportedly as a catalyst. But it seems a strange chemical for a catalyst in my limited experience. And I cannot really figure out what its role is. I'd love some enlightenment.

It is an oxydoredox reaction as such the results depends on the pH, some reactions occurs into acidic media (H(+)) and others into basic media (OH(-))...see oxydoredox tables.

The reducer is the sucrose ...aldehyd turned into carboxylic and polyols turned into keto groups and further cleaved into oxalic acid and carbonic acid.

The oxydiser is the purple permanganate anion (MnO4(-)) turning into green manganate anion (MnO4(2-)) and then further into pale pink manganous cation (Mn(2+)).
So oxydation state of Mn goes from +7 to +6 to +2.

The H(+) or OH(-) are recovered from the water solvent.




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[*] posted on 25-7-2016 at 04:01


Quote: Originally posted by Ramium  
I made this complex https://upload.wikimedia.org/wikipedia/commons/0/00/Glycerol...

I added some glycerol to a suspension of copper(ii) hydroxide in dilute sodium hydroxide solution and ended up with a beautiful solution of the complex.

My question is, how can I isolate the complex from this solution?

Will adding ethanol make the complex precipitate?

Probably not with ethanol that will be a competitive complexator to 1,2,3-propantriol...maybe try adding some diethylether.




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[*] posted on 25-7-2016 at 04:03


Quote: Originally posted by RogueRose  
I have seen a lot of yeast nutrients/energizers that contain DAP and I have also seen some that have ammonium sulfate in place of DAP. From what I have read the reason for putting these in with the yeast is to provide nitrogen to the yeast. My question is whether MAP can be used instead of DAP (with adjustments for the fact MAP has 1/2 the N as DAP). Also is there any reason that DAP is better than ammonium sulfate?

Also pH addaptation because the trimming effect on pH will not be the same from MAP vs DAP...and of course the osmotic pressure...




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[*] posted on 25-7-2016 at 07:42


Quote: Originally posted by PHILOU Zrealone  

Probably not with ethanol that will be a competitive complexator to 1,2,3-propantriol...maybe try adding some diethylether.

Ethanol will be monodentate, and unlikely to compete with the chelating gylerol.




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[*] posted on 26-7-2016 at 09:12
palladium alternate


whats a good alternative to palladium acetate
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