menime (Stranger)
09-03-03 22:45
No 457060
      Borohydride reduction,please advise..  Bookmark   

SWIM did his best with ketone,no one replied to my question-oh well.Seemed OK. Next SWIM followed LaBTop's procedure, with a little molar excess of NaBH4 and a little excess MeNH2,and all seemed to go OK.When doing the work up,SWIM has a not expected gray brown oily emulsion layer as well.SWIM could see oil drops in it, and has shaken with DCM to extract those freebase (hope!)oil drops .The DCM layer is a dark fleshy color on the bottom, then the "emulsion" floats on this, then a minor pinkish water layer on top of that....this water layer smells MeNH2-ish.Should swim throw it all in a flask and distill?Or distill off the DCM alone and see what's there? Thanks for tips...
 
 
 
 
    menime
(Stranger)
09-04-03 03:13
No 457096
      Part 2  Bookmark   

SWIM started with 280g redistilled pale yellow suspected ketone,30g NaBH4,125g MeNH2 freebase in MeOH-stirred 36 hours.Distilled DCM layer to recover 205g browny oil with a touch of yellow.Doesn't smell at all like ketone.The emulsion layer is oily and weighs 10g....extracted the water/alcohol layer with lots of DCM,so probly none there.Sound OK? Thanks for any info...
 
 
 
 
    menime
(Stranger)
09-04-03 05:23
No 457107
      Beware Evil Vacuum Leaks  Bookmark   

Ketone was not ketone..a leak in the vacuum line raised the boiling point to the right temp and fooled me....after fixing the pinhole,saf and "ketone" have the same boiling point.Damdamdamdam...it looked and smelled so good.Anyways,recovered more of my "ketone"after putting the water/MeOH in the freezer.Mebbe the benzo wacker would be better...
 
 
 
 
    hest
(Hive Adickt)
09-04-03 16:55
No 457168
      TLC  Bookmark   

Atleast check your product with TLC all the time, will spare you a lot of trouble.
 
 
 
 
    Vitus_Verdegast
(Hive Bee)
09-04-03 20:12
No 457186
      I second that - always use TLC !  Bookmark   

If your 'ketone' was actually safrole or isosafrole, then now after reducing with NaBH4 you will have dihydrosafrole (double bond reduced to alkane). This compound is pretty useless, unless you're into piperonyl butoxide analogues tongue.


Also, next time when you're confronted with a nasty emulsion, you might want to try vacuum filtering the whole lot. This will remove the crap that is causing the emulsion and will most of the time leave you with two nice, easy to separate layers.

A Dream Within A Dream (http://www.poedecoder.com/Qrisse/works/dreamw.html)
 
 
 
 
    pooky
(Stranger)
09-04-03 20:59
No 457192
      Keep trying  Bookmark   

Nice try on your attempt & don't give up after the first try.LaBTop says in his writeup check and double check your ketone...an understandable screw up happened.Maybe try the benzo wacker,apparently it's hard to have a complete disaster.
 
 
 
 
    pooky
09-04-03 21:16
      BTW
(Rated as: UTFSE!)
 Bookmark   
 
 
 
    Xicori
(Hive Bee)
09-04-03 22:16
No 457204
      thin layer chromatography, utfse to get ...  Bookmark   

thin layer chromatography, utfse to get yourself informed!
 
 
 
 
    pooky
09-05-03 00:45
      Lighten Up
(Rated as: insignificant)
 Bookmark