FriendlyFinger
Hazard to Self
Posts: 64
Registered: 14-3-2005
Member Is Offline
Mood: No Mood
|
|
Wet or dry IPA for MeNH2.HCl etxtraction
Can someone please explain how you can get MeNH2.HCl relatively free of HN4CL using wet IPA.
In those synths where people don't remove any NH4CL and proceed with removal of water until a "slush" remains, they crash out most of the NH4Cl then
distill out some of the IPA and extract again. But surley there will still be water in there, so are they getting a lot of NH4Cl in the end product?
I know it doesn't matter if it's used in the AL/Hg , but I'd like to know how much MeHN2.HCl is actually there. I'm asking because drying IPA with CaO
is a huge pain and not very economical when you concider time and CaO, but I don't like wasting chemicals.
I also know you don't have to recrystalise MeNH2.HCl if you filter out the NH4Cl at the right time, but is doesn't always work out that way with the
quality of formalin that I have access to.
So, how does crashing out the slush work? does IPA prefer to take up MeNH2.HCl before NH4Cl? Surley at the end you have to get rid of all that water
and use dry IPA , no? Otherwise how do you know how much MeNH2.HCl you actually have?
Kind regards,l
FF
|
|
|
Baalchemist
Harmless
Posts: 3
Registered: 3-3-2006
Member Is Offline
Mood: No Mood
|
|
Baalchemist used 99%IPA to extract out the MeAm from the 'mush' when performing a similar reaction. The mush was distilled as dry as possible first
under vac.
Godisnowhere
|
|
|
Organikum
resurrected
Posts: 2329
Registered: 12-10-2002
Location: Europe
Member Is Offline
Mood: busy and in love
|
|
| Quote: |
does IPA prefer to take up MeNH2.HCl before NH4Cl?
|
Sure. All alcohols do this and IPA more then EtOH for example. Dry hot IPA is preferred but an old
textbook stated that also an extraction with 95% EtOh yields methylamine of good purity, somewhat around 97% IIRC for sure something whats absolutely
ok for reductive aminations.
/ORG
|
|
|
bio2
Hazard to Others
Posts: 447
Registered: 15-1-2005
Member Is Offline
Mood: No Mood
|
|
.......I also know you don't have to recrystalise MeNH2.HCl if you filter out the NH4Cl at the right time, .........
This is true for the first crop if 2 crops of NH3HCl are taken first as in Vogels procedure. The other 2 crops don't look near as good.
IPA forms a 12% azeotrope with water so it can be used to dry the crystals or solution by distilling or in the vacuum dessicator (filter flask). This
makes bone dry
beautiful fluffy crystals (plates)
|
|
|
Madandcrazy
Hazard to Others
Posts: 117
Registered: 11-5-2005
Member Is Offline
Mood: annoyed
|
|
What is the MeNH2.HCl, surely a chlorin salt of the Methanolamin ?
You mean methanolamin
HOCH2NH2 , can it gotten by NH4Cl and MeOH ?
Maybe the chloroamin is the better way, or with a reaction with nitromethane.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
