I know that not to many people have a use for this substance but I do and maybe I can interest a few other people in it's synthesis.
I've been trying to figure out a decent synth for 1-amino-2-propanol (monoisopropanolamine) for months to no avail. At least not one that uses normal
lab conditions and quasi-OTC chems.
So I guess the question I am asking is:
How can I replace a hydrogen on the first carbon (on isopropanol chain) with an amino group using lab conditions and ~OTC chemicals?
And also, I know there are lots of OTC cleaning products that contain this chemical but I can't find any that have a significant amount that can be
isolated without A LOT of work and equipment.Maja - 19-9-2007 at 23:27
Try to use search button. I promise you will find answers to all your questions.MagicJigPipe - 19-9-2007 at 23:34
Nothing about 1-amino-2-propanol. There's even nothing about secondary amino alcohols at all. Trust me, I've been looking all over the internet and
reading all kinds of organic chem books and for some reason I can't find ANYTHING on synthesis of 2ndary amino alcohols in a lab setting. Very
frustrating. Guess I will just continue to advance my chemistry knowledge until I can figure it out myself.Boomer - 20-9-2007 at 04:27
The compound name rang a bell, and yes there is an idea that I postphoned indefinitely due to it being above my skills.
Does it require an Eschweiler-Clarke methylation to 1-dimethylamino-2-propanol, then a chlorination to 1-dimethylamino-2-chloropropane?
Is a nitrile the second main precursor, and a Grignard the crucial step?
In that case, good luck. I hope you are not after the money, though I don't know if there even is a market in yout country.
For me, it's always a "Why does the dog lick ... ? Becaus it can!" sort of thing. All my HE tests were not to open up safes, blackmail the railway, or
kill personal enemies either, but just done to see what is possible.Eclectic - 20-9-2007 at 04:32
You know what eclectic, I thought of that before but immediatley wrote it off because I figured the hydroxyl group would be placed at the end of the
chain. Which, now that I think about it wouldn't be problem but this seems to be my solution. Thank you, Eclectic.
Hmmmmm... Maybe I should go synthesize Methadone and sell it to orphans just so I could say it was Sauron's fault.
HA!! No, I'm not like that.
And Boomer, as far as that stuff goes, you are exactly correct. I agree with you 100 percent. Even though I haven't done anything significant as far
as drugs go in years. I would be the kind of person to synth something just to see if I can. I have created KCN before and I didn't use it to poison
anyone and I haven't used it in a synth yet but I did it and I got great satisfaction from doing it.MagicJigPipe - 20-9-2007 at 18:22
Damn, I just realized that the oxygen atom on propylene oxide is connected to carbons 1 & 2 on the propane chain. No shit! I can't believe I
missed this before. This is why it can make 1-amino-2-propanol when combined with ammonia in the right proportions.
This forum kicks ass. With the exception of Mr. Moral Moralton here.
[Edited on 20-9-2007 by MagicJigPipe]Polverone - 21-9-2007 at 08:52
More chemistry, less squabbling, please.MagicJigPipe - 22-9-2007 at 13:29
Yes, I agree. It seems as though 2-amino-1-propanol will be created as well. Is this correct?Eclectic - 22-9-2007 at 13:34
Not much. Read the reference I gave you.MagicJigPipe - 12-5-2008 at 22:08
I stumbled onto this after "UTFSE" and I remembered a question I had but never asked. I think this was my first post!
I know propylene glycol is made by adding water to propylene oxide. Since aqueous ammonia is used in the procedure, wouldn't an appreciable amount of
the diol be created in the process? I wonder what the equilibrium is for the particular reaction. Perhaps an excess of ammonia solution should be
used. Maybe that's what the original paper called for but I can't remember exactly.Nicodem - 12-5-2008 at 23:18
Ammonia is several magnitudes more nucleophilic than water.MagicJigPipe - 12-5-2008 at 23:52
Yes, that's why I figured a slight excess of ammonia should be used. As long as there is ammonia in solution there should be very minimal (if any)
glycol byproduct.
Thanks.Nicodem - 13-5-2008 at 00:38
No, using a slight excess of ammonia would yield no 1-amino-2-propanol since this is more nucleophilic than NH3 so it gets alkylated further till
tri-(2-hydroxypropyl)amine. Read the experimental in the paper Eclectic linked a few posts above. They used a 100-fold excess of ammonia to inhibit
overalkylation and they nevertheless got a mixture of mono-, di- and trialkylamines. They separated the 1-amino-2-propanol by distillation. The
reaction of water with propylene glycol in neutral to slightly basic conditions is negligible being too slow due to the very low nucleophilicity of
water. The only noteworthy side reactions are the overalkylations.MagicJigPipe - 13-5-2008 at 09:05
Okay, I get it now. Thanks again. I completely looked over the fact that NH3 could be substituted more than once. I was just making sure there
wasn't something that the paper might have overlooked as far as byproducts go. I kind of want to actually try the reaction but propylene oxide is
semi-expensive and there's really not too many other uses for it that I can think of. So, I would have an $80 gallon of epoxypropane with not too
many uses... Or I'd have a lot of 1-amino-2-propanol to play around with but... Also, not too much to do with it aside from the "usual" stuff. Is
there anything extremely interesting that this amino alcohol can be used for, that you know of?
I actually typed up a short "paper" on everything I learned on the synthesis of this compound (and similar amino alcohols) but I can't find it to save
my life. Sucks. For some reason I was so fascinated how something could have amine and alcohol properties at the same time... I know that's
simplistic but I didn't know then what I know now...
I also like the fact that (in theory) this is a clean reaction forming only water and isopropanolamine (water from the NH4OH and that was already
there).
Anyway, I'm done rambling. Thanks for making me look dumb
[Edited on 5-13-2008 by MagicJigPipe]smuv - 13-5-2008 at 12:13
This could also be made directly from propylene chlorohydrin which should predominantly be 1-chloropropan-2-ol. Synthesis from the epoxide is
probably what is done industrially...however with a choice between two chemicals of roughly equal toxicity, I'd rather work with the one which is
non-volatile.
[Edited on 13-5-2008 by smuv]MagicJigPipe - 13-5-2008 at 13:58
1-chloropropan-2-ol is not readily available, if at all.DJF90 - 13-5-2008 at 15:09
Dehydration of either propan-1-ol or propan-2-ol should yeild prop-1-ene. This could then be reacted with an aqeuous solution of hypochloric acid
(perhaps makeable from calcium hypochlorite? just add maybe sulphuric acid to precipitate out the calcium sulphate?) to yeild the chlorohydrin.
Other alternative that I can think of is using aqueous chlorine (or bromine... might be easier to work with) solution without the presence of light
(To avoid free radical substitution), as chlorine gas disproportionates in water to Cl- and OCl- (IIRC).
[Edited on 13-5-2008 by DJF90]S.C. Wack - 13-5-2008 at 16:08
Propylene is sold at the neighborhood hardware store (black bottles) here just like propane and MAPP. The oxide has some interesting uses.Polverone - 13-5-2008 at 16:27
Propylene can be treated in water with hypochlorous acid, organic hypochlorites, or chlorine to produce mixed chlorohydrins. Propylene glycol can be
treated with hydrogen chloride to produce the same, though the literature there is mostly older and more sparse (since industry usually wants
propylene glycol from chlorohydrin and not the other way around). I think the desired chlorohydrin forms more readily, at least when using HCl +
propylene glycol. If you're interested in chlorohydrin preparations suitable for the reagent-constrained amateur, there's some good older literature,
though you'll find more about ethylene than propylene, and will have to deal with inconsistent terminology.
All of this is pretty moot if you were just going to buy propylene oxide, though.smuv - 13-5-2008 at 17:39
Halohydrins and epoxides have been discussed here.
How were you planning to get the epoxide MJP? I think via the chlorohydrin would be the easiest route for this case. Were you considering peracids?Polverone - 13-5-2008 at 17:57
I think he was planning on just buying it. It seems to be available from at least some hobbyist suppliers as a fuel additive for go-karts. Routes from
the alkene or glycol are still interesting though, as these are far more available to the public in most places.MagicJigPipe - 13-5-2008 at 18:08
Honestly, if I end up doing this I'm just going to buy the propylene oxide. It's expensive but I'll get a lot of it (relative to how much I need).
$80 a gallon. It's probably impure but that's not too much of a concern for me. Although, it shouldn't be too "dirty" because it's to be used as a
fuel additive.
I thought about calling around to some of the racetracks around here but apparently it's now banned by the NHRA. I'm almost certain that people won't
have something that they can't use in an official race, but I suppose it's worth a try (I might find some nitromethane while I'm at it and both will
certainly be cheaper).
It would be fun to try and make the epoxide myself. Looking at the industrial processes, though, made me think twice about that.
I like the propylene glycol + HCl method that Polverone mentioned. It seems like the boiling points of the different chlorohydrins (does it matter?)
would make them difficult to seperate, though.
Quote:
Propylene is sold at the neighborhood hardware store (black bottles) here just like propane and MAPP. The oxide has some interesting uses.
Surely, you are not in the US because I would have heard of this. I have looked high and low for a source for alkenes to no avail. Not even
ethylene. I heard that some people in agriculture use it to synthetically ripen fruit but (of course) none of the ignorant yokels in my area had any
idea what ethylene or ethene was. That wasn't a surprise. Even if they had it, would they sell it to me? Who knows...
I suppose one of these days I'll get around to producing alkenes from the corresponding alcohols and sulfuric acid but until then, I'm looking for a
source. (even though my want for alkenes isn't related to this procedure).Polverone - 13-5-2008 at 18:18
Have you tried asking at welding/industrial gas suppliers? There are torches designed to run with oxygen/propylene. A cursory web search shows that 2
of the 3 gas suppliers in my area with at least a minimal web presence do carry propylene in cylinders, and I'm in the US.smuv - 13-5-2008 at 18:22
Well thats interesting; I had no idea it was a fuel additive. Propylene is pretty easy to make from isopropanol, since it is a secondary alcohol it
can be dehydrated under much more mild conditions than ethanol is, additionally it yields virtually no ether.
I want to point out that epoxies are pretty serious carcinogens, many of the common carcinogens are carcinogenic because in vivo our body metabolizes
them into epoxides (ex. benzene and toluene).Nicodem - 13-5-2008 at 22:02
Using NaOCl on propylene should give propylene oxide directly since the intermediate chlorohydrine cyclisizes to the epoxide in basic media. The
preparation of 1-chloro-2-propanol from propylene glycol was already discussed on this forum in a thread about 2-chloroethanol preparation (there are
some references there).
Also, both regioisomeric halohydrines derived from propylene give the same aminoalcohol if used in the reaction with ammonia since the first step is
always the cyclisation to propylene oxide. So it does not matter if you use 1-chloro-2-propanol, 2-chloro-1-propanol or propylene oxide, the product
in nucleophilic substitutions is always the same. A normal SN2 on 1,2-halohydrines is not possible due to the neighboring group
participation(cyclisation to an epoxide followed by an SN2 on the epoxide ring; thus leading to retention of configuration). A similar neighboring
group participation is observed in alpha-halo-carboxylic acids (for example the reaction of 2-chloropropanoic acid with amines, etc.).MagicJigPipe - 13-5-2008 at 22:15
NaOCl on propylene, eh? That would be an interesting setup. Or perhaps just a simple "bubbling through" type setup (a la chlorine and toluene) would
suffice. Then just distill...
Even though I doubt there would be information on this I will do a search tomorrow (it's late...)
Thanks for the information, Nicodem.S.C. Wack - 14-5-2008 at 03:28
Quote:
Originally posted by MagicJigPipe
Surely, you are not in the US because I would have heard of this.
I'd make up the fact that I'm in Bumfuck, USA by choice? (I'd move to a wet spot of WA or OR if I could afford it). I sure go to a lot of trouble to
use amerikan spellings. I traded my euros for dollars so I could post this picture featuring $1 coins that are keeping the bottle from rolling onto my
lap.
A search of Ace using the magic word propylene gives the impression that they sell Matheson product in containers a little smaller than this one.
Propylene glycol would be a lot cheaper.
MagicJigPipe - 14-5-2008 at 10:15
I meant no offense by it. Ace must be the only place. I have not been to the solitary Ace Hardware in my area (~25miles). Thanks, though. I shall
check this out.
I didn't notice that your info says you're in the US.
Also, I can get propylene glycol by the 5 gallon jug for ~$60. I hate that glycols are so expensive. Even ethylene glycol is $9 a gallon.
[Edited on 5-14-2008 by MagicJigPipe]mfilip62 - 16-12-2017 at 02:47
I would suggest propylene glycol and HaloAcetone as starting materials!
If polyols like PG follow the same chemistry as normal alcohols once could selectively
halogenate primary or secondary -OH (secodary maybe by using Lucas reagent than
do the Finkelstein reaction to replace Cl by I and react it with desired amine!
Other route would be reacting hydroxyacetone with Hydroxylamine followd by mild reduction
or reacting HaloAcetone with desired amine (with some catalyst like DIPEA/DIEA aka Hűgins base!) folowed by transforming =O into -OH!
Mixture of isomeres is not problem.
Once you halogenate remaining -OH group you can re-arrange the molecule by Aziridinium
mechanism.
Those are by far,most easyest way I can think of for producing some,at least one of the mentioned method SHOULD WORK! (I spend whole summer
researching secondary and tartiary
halogenpropylamines)
