AirCowPeaCock
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Failed Methylethyl ketazine synthesis
I attempted a methyl-ethyl ketazine synthesis based on nurdrage's instructions, I used a 4% solution of NH4OH though. Added the sodium hypo-chlorite
by burette (6%) to the MEK Ammonium hydroxide solution over 2 or so hours. All was done under an ice-bath. Set the beaker covered aside overnight.
The next morning a layer of what appeared to be the ketazine was floating on top, thin but definitely there. The fluid was still cloudy so I gave it
another few hours. When I returned the layer was gone and the solution turned a bright pink orange. The solution smelt strongly of MEK when I poured
it out. What went wrong? Why the color change? I'm going to attempt again today with a 20% solution NH4OH--was the concentration the problem?
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mr.crow
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Definitely the concentration. Also stoichiometry, there was probably way too much bleach/NaOH which hydrolized the product
Double, double toil and trouble; Fire burn, and caldron bubble
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AirCowPeaCock
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I did have a little excess bleach, but certainly not way to much.. But what compound was pink? sodium salt of MEK? Does that even exist? Partially
oxidized MEK?--From extra Chloramine, or just extra bleach?
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AirCowPeaCock
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Hows this:
166.7 g 6% NaClO sol. added by burret over 2 hrs to
92 g 20% NH4OH sol. mixed with
19.4 g MEK?
stiring the whole time
[Edited on 1-10-2012 by AirCowPeaCock]
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UnintentionalChaos
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Orange color is gunk from base catalyzed aldol condensations of the MEK
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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AirCowPeaCock
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Ok, Thank you
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aaparatuss
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I hope things work out for you this go round, but if you had 20% ammonia available what where you hoping to accomplish by using 4% concentration?
Im still working out the equilibrium but I was wondering if adding urea to a weaker ammonia solution will enhance chloramine formation and hence
ketazine formation.
The point being 10% ammonia solution is what is available.
goodluck
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AirCowPeaCock
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4% was what was avalible off the shelf.. im making some 20-30%(hopefully) as we speak. Its looking good!(:
BOLD
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mr.crow
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You can use Urea instead, check out UC235's excellent video on youtube
Double, double toil and trouble; Fire burn, and caldron bubble
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AirCowPeaCock
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I heard you get alot more by products with that method. Have experience with it?
BOLD
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UnintentionalChaos
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I extract the crude hydrazine by formation of the butananone azine, precluding NaCl contamination. It certainly worked fine for making luminol.
http://youtu.be/JCrDttuw5co
http://youtu.be/URIAB32Q_JQ
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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AirCowPeaCock
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I think I'm going to stick to the hypochlorate-ketazine process NurdRage mentions, if it doesn't work with the concentrated reagents, Ill try yours.
But after the Luminol synthesis I'll do with Urea just for fun, Maybe Ill use the Hydrazine.Sulfate to produce pure Hydrazine (solvated in
water)--I'll see what I can do about inert atmosphere distillation. So I can say I got that rocket fuel from my piss! 
BOLD
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aaparatuss
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http://books.google.com/books?id=VqosZeMjNjEC&pg=PR8&...
chapter 11 of this google book
Small-Scale Synthesis of Laboratory Reagents with Reaction Modeling
has pretty nice work up for alcoholic hydrazine. I would almost buy the book, but its too pricey....
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entropy51
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When I said in another
thread that you might want to read some chemistry books, I was trying to avoid saying "instead of watching nurd rage".
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AirCowPeaCock
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Im going to guess you don't like the cook book sytke because it doesn't teach much about therory
BOLD
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cyanureeves
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AirCowPeaCock how are you making your ammonia? i also used weak ammonia twice and my ketazine never separated so i did the other than nurd rage
method twice also.i got two powders that differ in taste,one is salty and the other one is bitter ,both make mirrors with silver nitrate.i still want
to do the katazine process but my ammonium nitrate sucked back water and exploded my glassware and no it was not borosilicate.what i thought was stout
ammonia was about as stout as afterbite anti- itch which is 3%. i cant even imagine what the 29% stuff sold on e-bay smells like.
[Edited on 13-1-2012 by cyanureeves]
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AirCowPeaCock
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You tasted hydrazine-sulfate..twice?!?!?!
BOLD
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cyanureeves
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AirCowPeaCock actually i have to admit i kept tasting the salty- lime one enough to shame myself. funny that i'm inquiring about ammonia because it
also has a prohibited addiction quality affect on me.
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vmelkon
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**** Oops scratch that. I took the RFB off the condenser this morning and had a look from the bottom. There are long sharp crystals in there!
I did this reaction a couple of days ago. I used ammonia bought at Walmart. It says goldex on it
-250 mL ammonia
-75 mL MEK
-250 mL bleach 4%
The reaction worked! I obtained 10 - 15 mL of methyl ethyl ketazine.
Now for the problem. I added 62 mL of 6M H2SO4. It did form some a slight cloudiness which I presume was hydrazine sulfate.
I distilled it to drive off the MEK. It turned an orange color and is cloudy. What is this stuff?
I also collected the vapors since I wanted to recycle the MEK. It has 2 layers. Weird.
Could it be that my H2SO4 contain Pb++ because it comes from batteries and it caused problems?
[Edited on 21-11-2012 by vmelkon]
[Edited on 21-11-2012 by vmelkon]
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Mailinmypocket
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I have wondered why the ketazine approach seems to be the preferred one... I have always used the method in this book, I will attach the process here.
If this poses a problem with the author I will remove it. There is no need for MEK and the process is very straighforward, all you need is some EDTA
which is cheap and easy to buy on eBay and the like.
"In the present experiment, these are bound by the addition of a small amount of EDTA (~1 g/mol hypochlorite) [13]. The use of EDTA
substantially reduces foaming and improves the purity of final product by keeping impurities in solution rather than in suspension."
The procedure is as follows:
11.3•…Experimental
11.3.1•…Hydrazine Sulfate
It is not necessary to use costly analytical-grade urea in this preparation. The technical- grade urea suffices, provided it is treated with ammonia
to a pH of ~10.5 subsequent to dissolution in water, followed by standing for several hours and filtration of precipitates of iron hydroxide, etc.
To begin, 76 g (1.9 mol) of NaOH is dissolved in 68 mL H2O (this is about the minimum amount of water required at 25°C) and carefully added to 560 g
(475 mL, 0.73 mol) of 11.5% NaOCl solution (these quantities can be adjusted if a hypochlorite solution of slightly different concentration is used),
and the mixture cooled to approximately −10°C. Although the basified hypochlorite solution can be used at initial temperatures of up to 10°C,
lower initial temperatures allow faster hypochlorite addition and, hence, shorter reaction times.
Next, 54 g (0.9 mol) of urea is dissolved in 46 mL of water (approximately the minimum amount). The dissolution is very endothermic and, hence, some
heating is necessary to speed the process. The solution is poured into a 1-L, two-neck, flatbottom reaction flask equipped with a thermometer and a
pressure-equalized dropping funnel, and surrounded by an ice–salt mixture. The dropping funnel outlet is loosely blocked by glass wool to hinder the
inflow of oxygen (which slowly oxidizes the hydrazine) and is either vented in the fume hood or bubbled through an acidified KMnO4 solution that
oxidizes the hydrazine.
A 3–4-cm stir bar is then inserted, 0.7 g EDTA is added, and the solution stirred while cooling to a temperature of about 8°C, at which point it
becomes opaque and quite viscous. The basified hypochlorite solution is poured into the dropping funnel and run into the urea solution at such a rate
that the temperature does not rise above 10°C. This should correspond to about 3–4 drops/sec., while the whole addition takes about 40 min. A much
faster addition rate with a total addition time of 10 min raises the temperature to 25°C toward the end of the reaction with an increase in gas
evolution due to Reaction 11.7, and yield loss of about 30%. However, even in this case, there is no substantive frothing.
When the reagents are fully mixed at a temperature of about 10°C, the solution is still noticeably yellow due to a substantial portion of unreacted
hypochlorite. The temperature now needs to be raised to 72°C as quickly as possible to complete Reaction 11.4 and maximize the yield of the hydrazine
intermediate, since a slow reaction favors the loss mechanism, Reaction 11.7. In practice, it is only necessary to heat externally to about 40°C,
since a rapid exotherm (~4°C/min) commences at this point. As the temperature rises above 50°C, the deepening of color is due to the unreacted
hypochlorite . When 72°C is reached, the reaction vessel is rapidly removed from the water bath and lowered into ice water. As the mixture cools
below 50°C, it becomes essentially colorless, showing that all hypochlorite has reacted.
When the temperature of the reaction mixture has dropped below 10°C, 188 mL of 32% HCl (1.9 mol) chilled to −10°C is run in while stirring at
such a rate that the temperature does not exceed 10°C. This minimizes the decomposition of hydrazine (the nitrogen evolved at this stage accounts for
about 8% yield loss) as well as hydrazine loss in the CO2 flux. Initially, the addition is accompanied by the evolution of thick white fumes due to
the formation of hydrazine hydrochloride; however, this soon clears. Next, a chilled mixture of 53 mL H2SO4 (1 mol) in 50 mL water is added at about 1
drop/sec., allowing the temperature to rise to just below 30°C.
The initial stages of the addition are visually accompanied only by the evolution of residual CO2 gas from the bicarbonate in solution because neutral
hydrazine sulfate is very soluble. However, after about 0.3 mol of acid has been added, the bisulfate starts precipitating and the solution clouds.
After all H2SO4 has been added, the solution is stirred for a further 15–30 min and then chilled in ice water. The added H2SO4 corresponds to a 0.55
molar excess, which lowers residual dissolved N2H6SO4 to about 1 g.
The precipitate is suction filtered, washed several times in situ with cold alcohol, and oven-dried at 100°C. The yield of the final product is
58–60 g N2H6SO4, which is 62% based on hypochlorite.
I've done this procedure twice now, on a scaled down run, and obtained ~20g each time. It can also be done easily in a few hours, which is nice.
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