Sauron
International Hazard
Posts: 5351
Registered: 22-12-2006
Location: Barad-Dur, Mordor
Member Is Offline
Mood: metastable
|
|
Preparation of Functionalized Tertiary Amines
I have not been able to find any literature on this as yet, but based on that reference Nicodem dug up appearing in the Hunig's base thread, I suspect
that di-isopropylamine can be directly alkylated with 2-chloroethanol (ethylene chlorohydrin) if conditions can be established to force this.
The target compound is di-isopropylethanolamine.
A leg up for such a reaction may be to conduct it in presence of a 50% molar excess of DIEA (Hunig's base) in order to suppress side reactions such as
quaternization.
The relatively low boiling point of the DIPA may dictate a pressure reaction, if reflux does not suffice. So be it.
[Edited on 24-6-2008 by Sauron]
Attachment: http___www.arkat-usa.pdf (54kB)
This file has been downloaded 449 times
Sic gorgeamus a los subjectatus nunc.
|
|
|
Ritter
Hazard to Others
Posts: 370
Registered: 20-6-2008
Location: Earth
Member Is Offline
Mood: Curious
|
|
| Quote: | Originally posted by Sauron
The target compound is di-isopropylethanolamine.
|
Where have I seen that compound before? Seems familiar!
When I worked for Union Carbide, they made alkanolamines such as this by reacting secondary amines with ethylene oxide, which you can get by
dehydrohalogenating ethylene chlorohydrin. They got it by oxidizing ethylene.
[Edited on 24-6-2008 by Ritter]
Ritter
=============================
\"The production of too many useful things results in too many useless people.\"
Karl Marx
|
|
|
Sauron
International Hazard
Posts: 5351
Registered: 22-12-2006
Location: Barad-Dur, Mordor
Member Is Offline
Mood: metastable
|
|
Aldrich sells isopropyl ethanolamine but it is 70% tech grade, balance being the tertiary diethanolamine. This is obviously less hindered than
di-isopropylamine, and I would guess that since DIEA (employed as per that paper posted above) suppresses quaternization, the 30% tertiary amine will
not react at all and cab be ignored.
Ethylene oxide would be a great choice for industrial prep. Not so convenient on the bench. As you mention, I'd have to make it out of ClEtOH and so
why not just use the chlorohydrin itself in a brute force alkylation?
Anyway banning the alkanolamine is silly, just as silly as banning pinacolyl alcohol for its use in GD. These are not the toxic principles. By this
logic they ought to have banned 2-propanol and ethanol! Just the sort of rectal/cranial inversion that the diplomats and UN are noted for.
Sic gorgeamus a los subjectatus nunc.
|
|
|
Ritter
Hazard to Others
Posts: 370
Registered: 20-6-2008
Location: Earth
Member Is Offline
Mood: Curious
|
|
| Quote: | Originally posted by Sauron
Ethylene oxide would be a great choice for industrial prep. Not so convenient on the bench. As you mention, I'd have to make it out of ClEtOH and so
why not just use the chlorohydrin itself in a brute force alkylation? |
I think you would need to react the diisopropylamine with BuLi first, then add the chlorohydrin to the amine Li salt. Making the EO in situ
by adding 2M NaOH to a mixture of amine & chlorohydrin is the other option.
| Quote: | | Anyway banning the alkanolamine is silly, just as silly as banning pinacolyl alcohol for its use in GD. These are not the toxic principles. By this
logic they ought to have banned 2-propanol and ethanol! Just the sort of rectal/cranial inversion that the diplomats and UN are noted for.
|
Any close analog of DIEA would likely give you a pretty nasty end product: dicyclopropyl or dicyclobutyl should work just fine. And analogs of
pinacolyl alcohol would likely serve just as well.
Ritter
=============================
\"The production of too many useful things results in too many useless people.\"
Karl Marx
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
