lancer3000
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Purification with Sodium Bisulfite?
Good Evening guys.
I need a bit of re-assurance on this process at hand please.
I have heard of the use of sodium bisulfite for use of purification of amine, by removing un-reacted amide, and other unknowns. Please advise.
A little run down:
It involves adding sodium bisulfite to solution until Ph reaches around 11. A layer separates, upper aqueous, lower a oil/freebase.
The upper aqueous layer is decanted, and dripped slowly onto a naoh/h20 solution heated to 70c, stirred, and cooled. Extract with solvent, and decant
solvent. This is then dried, filtered, and gassed.
The oil layer must contain more impurities I imagine? This is heated with solvent until almost boiling, then settles, and solvent decanted off.
Repeated 3 times. Chilled in freezer, and filtered. THIS is where the amide will remain in the filter.
This oil is then washed 3 times with a 5% naoh solution, and naoh solution discarded. Solvent is extracted with hcl until ph 7, and decanted, than
repeated with hcl until ph 2-3. extracts combined. washed 3 times with solvent. This is then mixed with naoh + nacl + h2o. solution is extracted
with xylene (gently), dried and gassed.
**seems like a lot of steps, but this probably leaves a nice product. Does this all sound proper, or can any of it be simplifed?
Thanks, and have a great weekend.
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Nicodem
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Doesn't make any sense to me.
PS: Open unanswerable and/or referenceless threads only in the Beginnings section where I'm moving this.
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Nicodem
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Thread Moved
1-10-2011 at 01:33 |
lancer3000
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doesnt adding bisulfite, attach itself to other things, allowing it to be filtered/separated from the unwanted, then removed with an acid? I think
this is where it is going, probably gives nicodem a better idea...
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