The Vespiary

The Hive => Newbee Forum => Topic started by: edo on January 30, 2004, 03:58:00 AM

Title: confirm wacker oxidation Bright Star Synthesis
Post by: edo on January 30, 2004, 03:58:00 AM

Hello Fellow bees,
   Swim has been using TFSE for a loooong time now and has learned alot.

Swim wants to make sure he understand the washes in
BS synth correctly.

After 7 hours swim will flood solution with acidic water (50ml HCl+1.5L water)shake and let it settle.
Dump(throw out) out top layer.
Then swim will wash bottom layer with 100ml DCM.
Wash top layer again with 100ml DCM.
Combin2 2xDCM wash and organic layer.  stir??
Wash DCM/organic layer with 150ml 10%NaOH.
Dump out top layer and wash bottom layer with another 10%NaOH.
Dump top layer keep bottom layer
Put in freezer or distill,

Is this correct?

Thankz !! :)  ;D  :)

ps. Is swim supposed to flood with all 1.55L of acidic water or only a portion ??

Title: Don't dump it !
Post by: wolfx on January 30, 2004, 09:47:00 PM

When you flood it with the 10 % HCl solution, the ketone falls to the bottom, you will see it as a separate layer, but there is ALSO a lot of ketone dissolved in the upper water layer. Don't throw it away, extract with DCM twice, AT LEAST, and combine with the bottom layer, THEN do the washings. Please read BS synthesis and use TFSE. Lots of info. Read and plan more.

Title: BS Wacker for dummies
Post by: edo on January 31, 2004, 02:23:00 AM

Thanks for ur time !!

So it's

Flood soltion with acidic water(shake let settle 10 min)
Decant top layer(wash top layer 2x100ml DCM)
Combine DCM wash(200ml)with origional (organic)bottom layer(shake)
Wash DCM/organic layer 2x150ml 10% NaOH(let settle)
Dump(throw out top layer)
freeze or distill

correct !?!?

Title: Decant top layer(wash top layer 2x100ml DCM)...
Post by: Antibody2 on January 31, 2004, 03:48:00 AM

Decant top layer(wash top layer 2x100ml DCM)actually you are extracting with DCM, n0t washing
Combine DCM wash(200ml)with origional (organic)bottom layer(shake)
Wash DCM/organic layer 2x150ml 10% NaOH(let settle)you will likely get a good emulsion here if you wash directly with 10% NaOH, a suggestion would be to wash with dH2O 1st, then with 5% NaHCO3, then your 10% NaOH, then another dH20
Dump(throw out top layer)yes,all aqueous washes will form the top layer, but you might consider pooling them for 1 back extraction(optional)
freeze or distill you should dry your organic layer with MgSO4 1st then distill, freezing will accomplish nothing, certainly no way of purifiing.

good luck

Title: do i filter MgSo4 before i distill?
Post by: edo on February 05, 2004, 07:28:00 AM

do i filter MgSo4 before i distill?

Title: Filter
Post by: hsark on February 05, 2004, 07:49:00 AM

Yes. Or you can filter your solution through a filtering apparatus if you have one. If not get one or make one. Good luck.

Title: :)
Post by: Just4Fun on February 11, 2004, 12:54:00 AM

Title: Not a necessity
Post by: Grouch on April 18, 2004, 04:41:00 AM

You don't have to filer the drying agent.  You can just pour it off and then rinse the drying agent a few times with some clean solvent and add it to what you're about to evaporate.