| Pages:
1
2
3
4 |
Waffles SS
Fighter
Posts: 998
Registered: 7-12-2009
Member Is Offline
|
|
Ethylamine Synthesis
| Quote: |
Ethylamine is an organic compound with the formula CH3CH2NH2. This colourless gas has a strong ammonia-like odor. It is miscible with virtually all
solvents and is considered to be a weak base, as is typical for amines. Ethylamine is widely used in chemical industry and organic synthesis.
Ethylamine is produced on a large scale by two processes. Most commonly ethanol and ammonia are combined in the presence of an oxide catalyst:
CH3CH2OH + NH3 → CH3CH2NH2 + H2O
In this reaction, ethylamine is coproduced together with diethylamine and triethylamine. In aggregate, approximately 80M kilograms/year of these three
amines are produced industrially. It is also produced by reductive amination of acetaldehyde.
CH3CHO + NH3 + H2 → CH3CH2NH2 + H2O
Ethylamine can be prepared by several other routes, but these are not economical. Ethylene and ammonia combine to give ethylamine in the presence of
an sodium amide or related basic catalysts.
H2C=CH2 + NH3 → CH3CH2NH2
Hydrogenation of acetonitrile, acetamide, and nitroethane affords ethylamine. These reactions can be effected stoichiometrically using lithium
aluminium hydride. In another route, ethylamine can be synthesized via nucleophilic substitution of a haloethane (such as chloroethane or bromoethane)
with ammonia, utilizing a strong base such as potassium hydroxide. This method affords significant amounts of byproducts, including diethylamine and
triethylamine.
CH3CH2Cl + NH3 + KOH → CH3CH2NH2 + KCl + H2O
http://en.wikipedia.org/wiki/Ethylamine
|
I am looking for easier method but It seems making Ethylamine is more difficult than making Methylamine.Anyone know easier method?
Anyone has more info about ethylamine?like boiling poit?decompose temp?
Solubility of ethylamine and its chloride salt in acetone ,Ethanol(and in what solvent is insoluble)?
[Edited on 20-1-2012 by Waffles SS]
|
|
|
Organikum
resurrected
Posts: 2339
Registered: 12-10-2002
Location: Europe
Member Is Offline
Mood: frustrated
|
|
The internet has all the physical properties of ethylamine, you know?
Making the acetamide looks not very demanding to me.
Reducing it, ok all are calling for LiAH but thats spoilsport, with LiAH everybody can.
So we know that HI rips virtually all Oxygen out of a molecule (and takes Nitrogen next if conditions are harsh enough). And we have an "O" to much
here.
Suggestion: NaI + NaH2PO2 + conc. HCl + H3PO4, heat until something starts to happen in the flask, add amide and reflux for some hours.
Does ethylamine form such a nice azeotrope with ethanol as methylamine does with methanol? Anyways, basify and distill the amine, it is not a gas like
meam at RT so thats a cake.
|
|
|
Waffles SS
Fighter
Posts: 998
Registered: 7-12-2009
Member Is Offline
|
|
Thanks, but i searched it in google and found nothing about solubility of it chloride salt in acetone and alcohol also nothing about decompose temp
Does amalgam method is effective in hydrogenation step?(instead of LiAH)
[Edited on 20-1-2012 by Waffles SS]
|
|
|
Organikum
resurrected
Posts: 2339
Registered: 12-10-2002
Location: Europe
Member Is Offline
Mood: frustrated
|
|
Quote: Originally posted by Waffles SS  | Thanks, but i searched it in google and found nothing about solubility of it chloride salt in acetone and alcohol also nothing about decompose temp
Does amalgam method is effective in hydrogenation step?(instead of LiAH)
[Edited on 20-1-2012 by Waffles SS] |
In a pipe bomb with serious heat and pressure who knows? But not just so AFAIK. The HI is the only way I know which doesn´t require hydrides, silanes
or alltogether. And it is usually high-yielding too, but I know, HI reactions are so yesterday, Unobtainiumhydride thats hip! 
|
|
|
entropy51
Gone, but not forgotten
Posts: 1612
Registered: 30-5-2009
Member Is Offline
Mood: Fissile
|
|
Posted somewhere on the forum is an old paper that says heating ethyl iodide, ethanol and ammonia in a sealed tube gives ethylamine with less than 10%
of higher substitution products. I can't immediately find the post, but it's here somewhere.
It does require heating in a sealed tube however.
|
|
|
Organikum
resurrected
Posts: 2339
Registered: 12-10-2002
Location: Europe
Member Is Offline
Mood: frustrated
|
|
tube
There is always a price to pay....
A tube made from soft steel, welded shut and on one end a sufficient threaded bore for a nice fat screw, maybe a safety bow, done. A thermocouple to
show the temp. from some distance and a big old iron bucket over all as the only danger is fluids spraying around if it breaks open. Soft steel will
not defragment, in the worst case there might be a leak. Wrap the threads of the screw with teflon tape, you might to want to open it oneday 
For large scale one of these ball-like propanetanks - 2 or 3l. Don´t know if you have them, here they are cheap, rated to 10atm and come with a
minimum of 10-fold safety marge (kind a law).
Isn´t there some damned catalyst for this amination? I remember something like triethylamine together with something else to catalyse this reaction
in a way that for iodine roomtemperature almost suffices.
Just cannot remember ..
|
|
|
entropy51
Gone, but not forgotten
Posts: 1612
Registered: 30-5-2009
Member Is Offline
Mood: Fissile
|
|
| Quote: Originally posted by Organikum | There is always a price to pay....
A tube made from soft steel, welded shut and on one end a sufficient threaded bore for a nice fat screw, maybe a safety bow, done. A thermocouple to
show the temp. from some distance and a big old iron bucket over all as the only danger is fluids spraying around if it breaks open. Soft steel will
not defragment, in the worst case there might be a leak. Wrap the threads of the screw with teflon tape, you might to want to open it oneday
For large scale one of these ball-like propanetanks - 2 or 3l. Don´t know if you have them, here they are cheap, rated to 10atm and come with a
minimum of 10-fold safety marge (kind a law).
Isn´t there some damned catalyst for this amination? I remember something like triethylamine together with something else to catalyse this reaction
in a way that for iodine roomtemperature almost suffices.
Just cannot remember .. |
I used thick Pyrex combustion tubing sealed in the Oxy-propane blast lamp. The
sealed tube was enclosed in a pipe bomb much as you describe. It only has to be heated in a boiling water bath for ethylamine.
I've never had one of these thick Pyrex tubes explode, but they scare my shirtless. The best catalyst in my opinion is several hits of Courvoisier
to give the chemist sufficient nerve to start heating the sucker.
Several of the old chemistry lab manuals in the forum library have detailed instructions for heating in sealed tubes and I recommend that anyone
contemplating an attempt at this method read ALL of them and follow the directions carefully.
I can't recall the details of the catalyst, but I think you are correct. Adding NH4NO3 increases the proportion of primary amine formed, but slows
down the reaction and is not necessary for ethylamine.
|
|
|
Ephoton
Hazard to Others
Posts: 463
Registered: 21-7-2005
Member Is Offline
Mood: trying to figure out why I need a dark room retreat when I live in a forest of wattle.
|
|
calcium propionate can be brought as a bread preservative E282.
ammonium propionate made form this can be rearranged thermally to propionamide very easily.
hoffman of propionamide gives ethylamine.
easy
you should be able to produce a few kilo's in a day this way
and the price per kilo would be around $20 too $50 (probably
cheaper than buying the shit)
no dangerous reductions or flamable solvents needed
just calcium propionate, aqua ammonia, aqua HCl, Bleach and caustic.
Ethyl amine could then be solvent extracted or boiled out of
hoffman turned to Hydrochloride with HCl and then freebased with
caustic to be distilled pure.
of course an excess of caustic when freebasing would be a good idea as it would hold onto most of the water created from the basing of a hydrochloride
with caustic.
on second thoughts sulfate would probably be less hygroscopic
and would let you boil the water off it easier than the hydrochloride.
[Edited on 21-1-2012 by Ephoton]
e3500 console login: root
bash-2.05#
|
|
|
Waffles SS
Fighter
Posts: 998
Registered: 7-12-2009
Member Is Offline
|
|
@Ephoton,Yes Hofmann Rearrangement is really interesting
I think we can customize below route for Ethylamine .
This method for making ethylamine is easier than methylamine because ethylamine boil at ~16c( I have access to calcium propionate )
But i think ammonium propionate can easily be made from ammonium sulfate and calcium propionate.but i dont know what temp needed for making ammonium
propionamide from ammonium propionate.
| Quote: |
Synthesis of Methylamine/Methylamine HCl via Hofmann Rearrangement
There are two approaches to producing an amine from an amide using the Hofmann rearrangement reaction. One way is to react the primary amide with an
alkaline-halide solution (eg - Sodium Hydroxide and Bromine). The other method is to use an alkaline-hypohalite solution (eg - Sodium Hydroxide and
Calcium Hypochlorite). The astute observer will notice that there is no chemical difference in the two processes. One produces the Hypohalite in situ,
the other uses the Hypohalite itself. Substitution of various halogens/halides/hypohalites/hydroxides is acceptable, but I feel I have picked the best
combination of maximal yield and ease of availability. Feel free to prove me wrong ;-). Also, at least one text specifies that Sodium Hypochlorite
produces much higher yields than Sodium Hypobromite. This delicious vindication is expected since Chlorine is a more reactive halogen than Bromine.
Now, we are going to use Calcium Hypochlorite, in the form of powdered pool shock, because concentrated Sodium Hypochlorite is a rare, unstable
creature indeed. Our yield will not suffer in the slightest because of this.
The main example presented will be the alkaline-hypohalite method as it is the easiest to acquire the necessary chemicals. It is of interest to note
that the alkaline-halide method is much easier to perform, processwise, in that it is more forgiving of sloppy technique.
The general theory behind the process is that the hypohalite will convert the amide to a haloamide. This then spontaneously changes to the isocyanate
when heated and decomposes to the amine from the water present. In effect, all that happens is that a Carbonyl (CO) group is stripped off the starting
amide to yield the corresponding amine. Yields pre-purification are around 80%, post-purification average around 65%. Certain uses of the resulting
amine will not require purification, though, so it will be left up to you whether or not to perform those steps.
To make methylamine we start with Acetamide. The general, unbalanced reaction process is thus:
CH3CONH2 + Ca(OCl)2 ----> (CH3CONCl)2Ca++ + H2O
then
(CH3CONCl)2Ca++ + NaOH ----> CH3NH2 + Na2CO3
CAUTION Methylamine is a poisonous, noxious inflammable gas. It has a strong ammonia/rotting fish-like odor. It's not as bad as Chlorine gas,
though, which can be produced if one is careless in the beginning!
You can scale these reactions up or down within reason. What is reasonable? I can't say, but I have done batches from .01 to 1 mole with no
difficulty. The key problems in scaling this reaction have to do with heat gradients in the flask and inadequate stirring. Use your own judgement,
keeping in mind that this is not an industrial process.
One reference to keep in mind (Thanks to J.W. Smith for sending this one) concerns the first step of the reaction.
Whitmore and Thorpe, J. of the Amer. Chemical Society, Vol 63, April 1941, p1118
"It was necessary to allow several hours for the formation of the N-chloroamide before heating to degradation temperature. With this modification it
was possible to prepare methylamine...consistently in 78% yield."
In my experience, this is a true statement. Please remember to keep the reactants well iced, though. Now, to begin:
In a large mixing bowl which can contain a smaller stainless steel mixing bowl, prepare an ice bath with water and salt to bring the temperature down
to -10C or so. Setup your glassware for simple distillation with magnetic stirring beforehand because certain steps need to be performed quickly. Use
a vacuum adapter to connect to the receiver flask, and attach some rubber or polypropylene tubing to the vaccum nipple to connect to a bubbler setup
(a funnel inverted in a beaker, or a plastic aquarium aerator tube). The distilling flask should be sitting in in a stainless steel bowl with nothing
in it (you will add pre-heated oil to the bowl).
NOTE In order to make this as painless as possible, please observe the following recommendations: 1) Keep the mixing bowl temperature as close to 0C
or less as possible; 2) Keep the Hypochlorite solution as it is being added as close to 0C or less as possible; 3) After half the Hypochlorite
solution has been added, place a plastic bag with 50-100g ice/salt/water mix into the bowl to help keep temperatures low (use this instead of directly
adding ice to the reactants, which adds a considerable volume of water making the process less volumetrically efficient); 4) Purchase an 8lb bag of
ice ahead of time!
Next you will prepare three solutions.
10g of Acetamide in 20mL of distilled water.
16.4g of Calcium Hypochlorite (Pool shock) in 50mL of hot distilled water
24g of Sodium Hydroxide (Lye) in 40mL of cold distilled water
This last solution should be prepared slowly as it is quite exothermic. Set all three aside in a freezer. Now prepare the mixing apparatus which will
be a stainless steel "mixing bowl" suspended in the ice/salt bath made earlier. We use a stainless steel bowl here so that heat transfer will be
maximal, while preventing any corrosive interaction. A glass bowl will not be sufficient for larger scale preparations as it will not conduct heat
fast enough to prevent the reactants from going over 10C (at which point the Haloamide will decompose and you'll have to start over). Take the Sodium
Hydroxide solution out of the freezer once it is cool, but not cold.
After the bowl has been sitting in the ice bath for a few minutes, add the Acetamide solution. Stir well until the solution has cooled to -10C. Now,
slowly add the Hypochlorite solution to the mixing bowl in bursts of no more than a couple mL while stirring vigorously. If you do this perfectly,
there will be no fizzing or bubbling at all. This depends on how cold you keep the mixture, and how slowly you add the pool shock! Realistically, the
considerable heat evolution of the reaction will make adding the last few mL a trying task! Keep an additional 50g of ice on hand to throw directly
into the mixture if necessary. This solution may evolve Chlorine gas so you should obviously perform this step under a fume hood or outside). Keep
stirring until it has calmed down and turned a turbid colorless to light green Let it sit for 2 hours, stirring occasionally and making sure that it
never gets warmer than 5C.
After the 2 hours is up, add the Sodium Hydroxide solution quickly with stirring. The solution should immediately turn a chalky, milk white. That's
because a lot of Sodium Carbonate just got generated. You no longer need be concerned over it's temperature, so you can leave the solution in this
state overnight if perhaps the hours have passed by too quickly and you've suddenly realized it's 2:00am.
Preheat a water bath on the stove (or wherever) to about 80C and place the stainless steel mixing bowl in it. Once the temperature of the solution
hits about 65C, take the bowl out and set aside while stirring all the while. This is where it rearranges, and the reaction is exothermic enough to
sustain it's temperature nicely. If you find the temperature climbing past 80C, immerse the bowl into some cold water briefly. After about 15 minutes
the temperature will start to fall, at which point you should transfer the whole mess to the distilling flask. Before you continue you need to choose
whether you want to make the hydrochloride salt or the aqueous solution of Methylamine, though.
Heat the flask using an oil bath to 100C after adding this solution to effect gentle boiling which will drive off the Methylamine as a gas. In my
experience, misbehavior is likely to occur at this point. One particular problem to watch out for is the sucking back of bubbler solution (be it plain
water or 6N HCl) into the receiver flask. I don't know why the pressure in the distilling flask would go below atmospheric, and therefore cause this
to happen, but it has several times with me. Needless to say, this results in a serious mess and botches the whole process (I have found a cure for
this by using an automotive one-way vacuum valve, like a PCV).
Continue heating the flask contents until you have collected around 100mL of distillate in the receiver.
For the aqueous solution: Place 18mL of cool distilled water into your bubbler setup. The expected, not theoretical, yield of Methylamine from this
amount of reactants is 7 grams. I have used a plastic aquarium aerator tube as the bubbler with excellent results. Sure beats using an inverted
funnel.
For the HCl salt: Do exactly as above except use 6N Hydrochloric Acid. 6N HCl may be produced by diluting 60.4mL of "Muriatic Acid" to 100mL with
distilled water. Evaporate the bubbler solution to dryness then add 15ml of water, 10mL 10% NaOH soln. and heat gently to a boil with constant motion
until dense white fumes appear. This will remove the Ammonium Chloride. Remove from heat while stirring as it cools down. Pulverize the dry residue,
then reflux with absolute Ethanol for several minutes. Filter the refluxed soln. on a heated Buchner or Hirsch funnel, then distill the alcohol off
the filtrate until crystals just begin to form. Allow the soln. to cool naturally to room temperature, then cool further in an ice bath. Filter the
solution on a chilled Buchner funnel with suction. The yield of Methylamine Hydrochloride should be around 55% of the theoretical.
To clean the white residue off of your glassware, dump some muriatic acid straight from the jug onto them and swirl.
References:
Journal of Chemical Education, v14, pg542
Organic Reactions volume 3
Vogels Elementary Practical Organic Chemistry, pg574
|
Do you know decompose temp of chloride salt of Ethylamine ?and solubility in acetone and EtOH?
[Edited on 21-1-2012 by Waffles SS]
|
|
|
mario840
Hazard to Others
Posts: 229
Registered: 20-1-2010
Member Is Offline
Mood: No Mood
|
|
Hahahahaha i knew it, on this forum are only google-amateur-chemists, to my thread no one can answer because they know nothing more than goole , in
this thread as always some useless method and theorizing bla bla bla bla , ethylamine is produced in good yields by reduction of nitroethane in many
methods for example : zinc/ammonium formate, Al/Hg etc. , reduction of nitrile gives a amine with one carbon more so reduction acetonitrile gives
ethylamine , acetonitrile is common solvent, cheap, and easy to buy, reduction cheapest al/hg. Cya
D. Gowda, B. Mahesh, & G. Shankare, Ind. J. Chem. Sect. B, 40, 75-77 (2001)
Syn Comm, Vol 33, No 2, pp 281-289 (2003)
|
|
|
AndersHoveland
Hazard to Other Members, due to repeated speculation and posting of untested highly dangerous procedures!
Posts: 1986
Registered: 2-3-2011
Member Is Offline
Mood: No Mood
|
|
There is not really any easy way for the hobbyist to make ethylamine. The most feasible route would probably be partial oxidation of ethanol to
acetaldehyde, then distillation with NH4Cl (or possibly (NH4)2SO4 fertilizer). The procedure would be similar to that used for making methylamine:
| Quote: |
Methylamine Hydrochloride from Ammonium Chloride and Formaldehyde
In a 5 liter round-bottomed flask, fitted with a stopper holding a condenser set for downward distillation and a thermomether which will extend well
into the liquid, are placed 4 kg (3711 ml, 47-53 moles) of technical formaldehyde (35-40 percent; d 1.078 at 20°C) and 2 kg (37 moles) of technical
ammonium chloride. The mixture is heated on the steam bath until no more distillate comes over and then over a flame until the temperature of the
solution reaches 104°C. The temperature is held at this point until no more distillate comes over (four to six hours). The distillate, which consists
of methylal (bp 42-43°C), methylformate and water may be treated with NaOH solution to recover methylal and sodium formate. The contents of the
reaction flask are cooled too room temp and the ammonium chloride which separates is filtered off. The mother liquor is concentrated on the steam bath
under reduced pressure to 2500 ml, and again cooled to room temp, whereupon a second crop of ammonium chloride separates. The total recovery of
ammonium chloride up to this point amounts to 780-815 grams. The mother liquor is again concentrated under reduced pressure until crystals begin to
form on the surface of the solution (1400-1500 ml). It is then cooled to room temperature, and a first crop of methylamine hydrochloride, containing
some ammonium chloride is obtained by filtering the cold solution. At this point 625-660 grams of crude product is obtained. The mother liquor is now
concentrated under reduced pressure to about 1000 ml, and cooled, and a second crop of methylamine hydrochloride (170-190 grams) is then filtered off.
This crop of crystals is washed with 250 cc of cold chloroform, and filtered to remove most of the dimethylamine hydrochloride which is present. After
the washing, the product weighs 140-150 grams. The original mother liquor is then evaporated under reduced pressure, as far as possible, by heating on
a steam bath, and the thick syrupy solution (about 350 ml) which remains is poured into a beaker and allowed to cool, with occasional stirring, in
order to prevent the formation of a solid cake, and the crystals obtained are washed with 250 ml of cold chloroform, the solution is filtered yielding
55-65 grams of product. There is no advantage in further concentrating the mother liquor, which contains mostly tetramethylmethylenediamine
hydrochloride, but no trimethylamine hydrochloride. The total yield of methylamine hydrochloride is 830-850 grams. The product contains water,
ammonium chloride and some dimethylamine hydrochloride. In order to obtain a pure product, the impure methylamine hydrochloride is recrystallized from
absolute ethanol (solubility 0.6g/100ml at 15°C), or preferably butyl alcohol (even less soluble). The recovery of ammonium chloride amounts to
100-150 grams, making the total recovery 850-950 grams. The yield of recrystallized methylamine hydrochloride is 600-750 grams (45-51 percent of
theory, based on the used up ammonium chloride).
A standard run, from 250 grams ammonium chloride and 500g 37% formaldehyde (containing 15% methanol), gives 100-134 grams methylamine hydrochloride,
27 grams dimethylamine hydrochloride and 81 grams of recovered ammonium chloride. The distillate contains methylal (formaldehyde dimethyl acetal) and
methyl formate, which after treatment with NaOH can yield 25g of sodium formate and 30 grams of methylal, as the compound cannot be separated by
fractional distillation, neutralization is the way to go. Ammonium chloride is very sparingly soluble in a concentrated solution of methylammonium
chloride, making the separation of the compounds pretty sharp.
Similarly, Hexamine and HCl may be used as the reactants instead, illustrating that the order of reaction of CH2O, NH3, and acid does not matter.
|
| Quote: |
Acetaldehyde
Place 260mL of 23% sulfuric acid in a 1500-mL flask. Connect an addition funnel to the flask, and set it up for vacuum distillation with a 500-mL
receiving flask. The receiving flask should be immersed in a salt-ice bath to cool the distillate when it comes over. Although a setup for vacuum
distillation is used, it is not necessary to apply a vacuum; the vacuum adapter merely provides a means of equalizing pressure. Prepare a solution of
100 g of sodium dichromate in 200 mL of water and 127 mL of ethyl alcohol. Factor in the amount of water that is already in the ethyl alcohol when
making the solution, i.e. 100 mL of 95% alcohol has 5 mL of water in it already. Place this solution in the addition funnel, position the stem of the
funnel such that it is about 3 cm above the surface of the acid. Heat the acid until it just begins to boil, then add the mixture in the funnel in a
steady stream to the acid. It will not be necessary to heat the flask during the addition because it will generate its own heat. The heat will be
sufficient to distill over the acetaldehyde along with some alcohol and waste acetal. If acetaldehyde vapors begin to escape from the flask, regulate
the distillation by decreasing the amount of dichromate solution being added. If the reaction flask does not boil on its own, gently heat it for a
short time until boiling begins.
The acetaldehyde thus obtained is difficult to distill from the alcohol and acetal mixed with it. It is therefore converted to aldehyde-ammonia, then
back to pure aldehyde. Place the crude acetaldehyde in a Florence flask of suitable volume to contain no more than two thirds of the liquid. Attach a
reflux condenser to the flask. Fill the condenser jacket with 30 °C water. It is only necessary to have the warm water in the jacket, not flowing.
Stop up the lower connecter to prevent water from leaking out. To the top of the condenser, attach a glass tube connected to a wash bottle filled with
50 mL of ethyl ether. This wash bottle is then connected to another wash bottle filled with 50 mL of ether. After all connections have been made, the
crude aldehyde is heated to a gentle boil for 5-10 minutes. The ether will absorb the acetaldehyde as it boils off. If the ether begins to rise up
into the connecting tube from the condenser to the wash bottle, increase the heating.
Combine the ether into a 150-mL beaker immersed in a salt-ice bath. Bubble dry ammonia gas into the ether through an inverted funnel or wide tube
immersed near the bottom of the beaker. Add ammonia until the ethereal solution smells strongly of ammonia. After about an hour, pure
‘ammonia-aldehyde’ should have separated out. Scrape the crystals from the beaker and collect them by suction filtration. Wash the crystals with a
small amount of ether, and allow them to dry in a closed drying heater, with the air constantly circulated through baked-dried CaCl2. The yield is
about 30 g.
To obtain pure acetaldehyde, dissolve 10 g of aldehyde-ammonia in 10 mL of water in a 50-mL flask. Add 28 mL of cold 29% sulfuric acid to the flask
and set it up for simple distillation. Heat the flask on a water bath to distill over the aldehyde. Place the receiving flask in a salt-ice bath to
cool the volatile acetaldehyde. Acetaldehyde is extremely volatile and cannot be stored satisfactorily unless it is refrigerated or sealed in glass
ampoules (not just capped), therefore it is necessary to prepare acetaldehyde each time it is needed. There is, however, an easier solution. A quick
and easy way to store acetaldehyde is to polymerize it to paraldehyde, which can be handled and stored easily, then depolymerize when it is to be
used. To polymerize acetaldehyde for storage, place it in a dry test tube and cautiously add 1 drop of concentrated sulfuric acid per 2 mL of
acetaldehyde in the tube. Mix thoroughly, the polymerization will begin to take place. Some gentle warming can hasten the reaction. After some minutes
add 3-4 mL of water per 2 mL of acetaldehyde, an insoluble precipitate of paraldehyde will form. Paraldehyde has anaesthetic and sedative properties.
To depolymerize paraldehyde back into acetaldehyde, place the paraldehyde into a round-bottom 200-mL Florence flask. Add 4-5 drops of concentrated
sulfuric acid for every 20 g (20 mL) of paraldehyde in the flask. Set the flask up for fractional distillation, use glass in the fractionating column.
Use a 125-mL Erlenmeyer flask as the receiver; keep it cool by immersing in an ice water (but not salt-ice) bath. Place a loose plug of cotton into
the Erlenmeyer flask to help reduce evaporation loss; it must be loose. Care must be taken to prevent the cotton from coming into contact with the
distillate. After setting up, heat the flask gently. The temperature of the distillate must not be allowed to rise above 35 °C as it will only
re-polymerize. The acetaldehyde thus prepared may then serve as a reactant for other procedures.
|
Both these procedures were archived from "The Hive".
|
|
|
Waffles SS
Fighter
Posts: 998
Registered: 7-12-2009
Member Is Offline
|
|
| Quote: Originally posted by AndersHoveland | There is not really any easy way for the hobbyist to make ethylamine. The most feasible route would probably be partial oxidation of ethanol to
acetaldehyde, then distillation with NH4Cl (or possibly (NH4)2SO4 fertilizer).
|
Thanks,
I think Hofmann Rearrangement is cheaper and easier method also there is better ways for producing Acetaldehyde
I tried vinyl acetate + aceic acid +catalyst(H2SO4) and got lot of pure acetaldehyde
|
|
|
smaerd
International Hazard
Posts: 1262
Registered: 23-1-2010
Member Is Offline
Mood: hmm...
|
|
I was at one point really interested in preparing my own triethylamine seeing as how all tertiary amine proton scavengers are really expensive and
darn near unobtainable.
What about the gassing dry ammonia into 90% ethanol solution then adding EtBr?(see attached articles)
I posted before asking for advice on gassing ammonia into ethanol solution and no one cared to lend any tips iirc... My best advice should you try
this route is do not use a glass pipet, and find some sort of gas dispersion tube. Not sure how well the inverted funnel trick would work. Unless of
course you have at your disposal a dewar style condenser and dry-ice/acetone. Unfortunately I do not.
Attachment: A MODIFIED METHOD FOR THE PREPARATION OF TRIETHYLAMINE.pdf (263kB)
This file has been downloaded 2891 times
Attachment: The Preparation of Ethylamine and Diethylamine.pdf (253kB)
This file has been downloaded 1855 times
[Edited on 21-1-2012 by smaerd]
|
|
|
Ephoton
Hazard to Others
Posts: 463
Registered: 21-7-2005
Member Is Offline
Mood: trying to figure out why I need a dark room retreat when I live in a forest of wattle.
|
|
| Quote: Originally posted by mario840 | Hahahahaha i knew it, on this forum are only google-amateur-chemists, to my thread no one can answer because they know nothing more than goole , in
this thread as always some useless method and theorizing bla bla bla bla , ethylamine is produced in good yields by reduction of nitroethane in many
methods for example : zinc/ammonium formate, Al/Hg etc. , reduction of nitrile gives a amine with one carbon more so reduction acetonitrile gives
ethylamine , acetonitrile is common solvent, cheap, and easy to buy, reduction cheapest al/hg. Cya
D. Gowda, B. Mahesh, & G. Shankare, Ind. J. Chem. Sect. B, 40, 75-77 (2001)
Syn Comm, Vol 33, No 2, pp 281-289 (2003) |
Are you alright in the head or what ?
google amatures nice one dude.
Hope you know your posting missinformation when you say that
you can reduce a nitrile with Al/Hg amalgums.
Anyway google doesnt work with tar button so I think you will find
a lot of us dont even use google anymore.
If we could reduce nitriles with amalgums PEA's would be a different kettle of fish.
e3500 console login: root
bash-2.05#
|
|
|
Waffles SS
Fighter
Posts: 998
Registered: 7-12-2009
Member Is Offline
|
|
What about ammonium ethyl sulfate?it should produce ethyl amine sulfate. isnt it?
|
|
|
Sedit
International Hazard
Posts: 1939
Registered: 23-11-2008
Member Is Offline
Mood: Manic Expressive
|
|
No it undergoes an elimination reaction releasing Ethane with no formation of Ethylamine. Since its an Ethylating reagent I am curious weather it can
be used to Ethylate an amine so that Ethylamine can be produced but under normal conditions such as that which create methylamine it will not work.
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
|
|
|
Arsole
Hazard to Self
Posts: 52
Registered: 21-1-2012
Location: USA
Member Is Offline
Mood: Sleepy
|
|
Could you make Ethyl Bromide and bubble Ammonia gas through that to create a mixture of Ethylamine, Diethylamine, and Triethylamine.
Separate the 3
Ethylamine: BP 16.6 C Miscible in water
Diethylamine: BP 55-56 C Miscible in water
Triethylamine: BP 89-90 C Solubility in water 5.5% at 20°C (So not much)
Could you Distill off the Ethylamine and use the differences in solubility between Diethylamine and Triethylamine to separate the two.
You could probably distill the Di and Tri as they are greater than 25C BP difference.
Am I wrong?
Thoughts, like fleas, jump from man to man, but they don't bite everybody.
-Stanisław Jerzy Lec
|
|
|
ScienceSquirrel
International Hazard
Posts: 1863
Registered: 18-6-2008
Location: Brittany
Member Is Offline
Mood: Dogs are pets but cats are little furry humans with four feet and self determination! 
|
|
| Quote: Originally posted by Arsole | Could you make Ethyl Bromide and bubble Ammonia gas through that to create a mixture of Ethylamine, Diethylamine, and Triethylamine.
Separate the 3
Ethylamine: BP 16.6 C Miscible in water
Diethylamine: BP 55-56 C Miscible in water
Triethylamine: BP 89-90 C Solubility in water 5.5% at 20°C (So not much)
Could you Distill off the Ethylamine and use the differences in solubility between Diethylamine and Triethylamine to separate the two.
You could probably distill the Di and Tri as they are greater than 25C BP difference.
Am I wrong?
|
In principal you are right but the reaction would probably require sodium amide in liquid ammonia to proceed at a decent rate. Separating the product
would be hard as well.
OK if you have an industrial plant with 50m fractionating towers but tough in a lab.
Ethylamine is a bit of a bugger to handle when pure as it boils below average room temperature in most labs.
For a lot of purposes an aqueous solution is adequate and a lot cheaper.
If I had to make it I would go for the Gabriel synthesis.
http://en.wikipedia.org/wiki/Gabriel_synthesis
|
|
|
Dr.Bob
International Hazard
Posts: 2753
Registered: 26-1-2011
Location: USA - NC
Member Is Offline
Mood: Mildly disgruntled scientist
|
|
| Quote: Originally posted by Arsole |
Could you Distill off the Ethylamine and use the differences in solubility between Diethylamine and Triethylamine to separate the two.
|
I don't think you could use water solubility to separate them, as once you add diethylamine to water, you create a new mixture, which would readily
dissolve triethylamine. Remember solubilities are determined with single, pure compounds, and most impure chemicals are much more soluble, as well as
the effect of adding a new chemical to the solvent changes its solvent properties, and almost always makes a better solvent. For example, many paint
strippers are a mix of non-polar and polar solvents, as that will dissolve much faster and much more stuff than any one solvent would do. So
purification of mixtures of liquids by solubility generally does not work well.
However, A decent still with even a moderate distillation column can separate liquids of different BPs quite well, if the distillation is done slowly
and carefully controlled. I have distilled Freon isomers from each other which only had a 1-3 C difference in BP, using a 3' fractionating column,
but for over 10C, it is not hard to distill compounds apart to a reasonable purity. Plus, if you want diethylamine, having a trace of triethylamine
would generally not hurt, is it is mostly non-reactive. Same way, you could remove traces of DEA from TEA by reacting the DEA with a chemical that
would form a new compound and then distill off the TEA. It would be a pain, but I have done such things before in a pinch.
|
|
|
Waffles SS
Fighter
Posts: 998
Registered: 7-12-2009
Member Is Offline
|
|
| Quote: Originally posted by ScienceSquirrel |
In principal you are right but the reaction would probably require sodium amide in liquid ammonia to proceed at a decent rate. Separating the product
would be hard as well.
OK if you have an industrial plant with 50m fractionating towers but tough in a lab.
Ethylamine is a bit of a bugger to handle when pure as it boils below average room temperature in most labs.
For a lot of purposes an aqueous solution is adequate and a lot cheaper.
If I had to make it I would go for the Gabriel synthesis.
http://en.wikipedia.org/wiki/Gabriel_synthesis
|
Thanks ScienceSquirrel ,
This is really interesting method
Also In the final step we can use basic solution instead of hydrazine(due to Toxicity of hydrazine)
Ethyl chloride easily can be made by ethanol and hydrochloric acid.
Do you know ratio or Instructions (example) for this method?
I think this method is easier than Hofmann Rearrangement method.I want to test this method
[Edited on 9-2-2012 by Waffles SS]
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
Easily? Please post the reference or the experimental data so we can judge by our selves.
|
|
|
entropy51
Gone, but not forgotten
Posts: 1612
Registered: 30-5-2009
Member Is Offline
Mood: Fissile
|
|
| Quote: Originally posted by Waffles SS |
Thanks ScienceSquirrel ,
This is really interesting method
Also In the final step we can use basic solution instead of hydrazine(due to Toxicity of hydrazine)
Ethyl chloride easily can be made by ethanol and hydrochloric acid.
Do you know ratio or Instructions (example) for this method?
I think this method is easier than Hofmann Rearrangement method.I want to test this method |
Ethyl bromide is
more easily made than ethyl chloride. Different members have reported preps for EtBr on the forum. Basically it just requires the distillation of a
mixture of ethanol, NaBr and H2SO4 with very cold water in the condenser.
I believe the protocol for the Gabriel synthesis of primary amines is in Vogel's textbook of practical organic chemistry in the forum library. It is
not a trivial exercise, but is not too difficult, especially if you can get phthalimide.
There are several threads pertaining to the preparation of ethyl chloride. Here is one of them: https://www.sciencemadness.org/whisper/viewthread.php?tid=13...
[Edited on 10-2-2012 by entropy51]
|
|
|
Waffles SS
Fighter
Posts: 998
Registered: 7-12-2009
Member Is Offline
|
|
In below topic you can find it:
http://www.sciencemadness.org/talk/viewthread.php?tid=2726
Ethanol + hydrochloric acid + ZnCl2(catalyst)
Yield is low but this is possible.
I think this method is cheaper , easier and safer than EthylBromide route and it doesnt need special equipment
this mean for me Easily
| Quote: |
The successful conversion of methyl and ethyl iodides
into the N-alkylphthalimides by reaction with potassium
phthalimide at 150°C was reported by Craebe and
Pictet in 1884. It was already known that N-alkylphthalimides
could be hydrolyzed to phthalic acid and
the primary amine, but it was Gabriel who appreciated
the significance of these reactions and formulated the
Synthesis which bears his name.
The Gabriel Synthesis of Primary Amines
Prof. M. S. Gibson1,
Dr. R. W. Bradshaw2,*
Article first published online: 17 DEC 2003
DOI: 10.1002/anie.196809191
|
The biggest problem is boiling point of ethyl halide(<100c)
This reaction happen near 150c and ethyl chloride or ethyl bromide boil below 100c.
I think i should gases ethyl halide into warm(150C) potassium phthalimide
[Edited on 10-2-2012 by Waffles SS]
|
|
|
Waffles SS
Fighter
Posts: 998
Registered: 7-12-2009
Member Is Offline
|
|
What about reduction of Nitroethane by(Sn/HCl)?
| Quote: |
2 CH3NO2 + 6 Sn + 12H+ 2 CH3NH2 + 3 Sn(IV) + 4 H2O
Cognate procedure: Setup a flask with reflux condenser in which .25 mol of nitromethane, .38 mol of granulated tin metal and a stirrer magnet have
been added. Carefully pour 115mL of 31.45% hydrochloric acid (muriatic acid) down the reflux condenser in 10-15mL increments, waiting for the reaction
to settle down before pouring the next aliquot. If the reaction seems to get out of hand (excessive frothing, vapor escaping the reflux condenser,
etc...) then quickly slide an ice bath in place until it slackens back down. Once all the HCl has been added, heat the mixture to reflux with an
electric mantle for 1hr. At the end of this time, allow to cool, preferably in an ice bath, then add, carefully, a chilled solution of 75g sodium
hydroxide in 125mL of water. If the flask contents start to bubble violently you will watch your yield go out the window, so add slowly! Since
methylamine readily dissolves in water, you will need to distill the reaction contents carefully to first liberate the 40% constant boiling solution
(bp: 53°C) and then the gas itself. The product is best captured by bubbling the distillation vapor into a beaker of hydrochloric acid (use a slight
molar excess of HCl to insure no loss). Proceed as above by evaporating the bubbler solution to yield the crystals (take care when evaporating HCl
solutions, as the excess acid will vaporize into the air, corroding ovens, lungs, etc...). [Vogel's, pg 892]
|
We can use Nitroethane instead of nitrimethane in above procedure
Nitro ethane can be prepared by below method:
Nitroethane from ethylsulfate, Desseigne variation.
http://www.sciencemadness.org/talk/viewthread.php?tid=15837#...
|
|
|
aliced25
Hazard to Others
Posts: 262
Registered: 31-7-2010
Member Is Offline
Mood: No Mood
|
|
Yep, nitroethane is the simplest of materials to access Ain't no issues with
the synthesis of that shit...
If monoethylamine, without di- and tri-ethylamine, is the target might I suggest the Hoffman is probably the best option for the amateur chemist.
Fucking around with phthaloyl groups for a low value intermediate would appear to be overkill.
From a Knight of the Realm: "Animated movies are not just for kids, they're also for adults who do a lot of drugs." Sir Paul McCartney
|
|
|
| Pages:
1
2
3
4 |
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
