06-06-03 03:45
No 438114
SWIM's having major problems w/ his ketone vac. distill....Using MM's writeup(the one SWIM's used almost 40 times now), SWIM vac. distills his ketone(vac is decent....saf comes over at 120 and ketone normally comes over at 160....again, just decent but great honey)....and today, after about an hour of distilling(temp at 50C), the whole mess just bubbled up into the condensor(and please please please don't say soap cuz SWIM washes thoroughly)....so SWIM let the whole mess cool, cleaned everything, and had another go at it....and once again, the same thing....any suggestions??
(Hive Bee)
06-06-03 03:48
No 438117
Aside from any suggestions(and please believe that all suggestions are very appreciated), would you all think that the bubblie mess can be saved...if so, how??
(Greenhorn)
06-06-03 04:17
No 438135
Swim has had this happen to him before. Did you do your washes good enough. Had a problem with that in the begining. Is your stirring good enough?
I went into the business for the money, and the art grew out of it.-Charlie Chaplin
(Hive Bee)
06-06-03 14:05
No 438218
SWIM always does all the MM washes everytime w/ wonderful results(except this time)....During the distill, the stirring seems to be pretty strong.
Can the mix be saved? Should SWIM hit the mix w/ DCM a few times and redo all the washes then do another DCM distill and re-vac it???
(Hive Bee)
06-06-03 16:52
No 438249
SWIM put the mix from Hell into the freezer and washed everything out.....and is now just waiting on some suggestions...SWIM doesn't wanna waste any good mdp2p that might be there but wants to know if it can be saved.
Update Again: After using TFSE all day, SWIM came across a post where someone else had similar problems, and Rhodium said to redistill so SWIM re-vac distilled again and again the bubbles went crazy(at the same temp....50C)....URGHH!!
(Greenhorn)
06-07-03 00:41
No 438329
Your problem is not that much of a problem really. Just distill your ketone out. Some of that black tar type shit will probably creep up the 3 way adapter and make it into your recieving flask. Don't worry about this right now. Just distill all your ketone out, then redistill your semi purified ketone to good pure ketone.
I went into the business for the money, and the art grew out of it.-Charlie Chaplin
(Daddy)
06-07-03 01:41
No 438341
is happening, you probably have a crack, tiny but important, somewhere in your glassworks.
I had the same happening to me once, and nearly drove me mad, but found a crack in the NS coppling from my condensor.
So check your glass.
It can also be a fault in your vacuumpump, broken O-rings, do you regulary change pumpoil?
Or do you use an aspirator (could be, you seem to have a vacuum of circa 10 mbar with ketone coming over at 160C)? Then check your O-rings, and the PP-body of your venturi tube.
I'm quit sure it must be something like this, because you stated you did the same procedure already 10th of times without foaming and bubbling.
This is almost ever an indication of a vacuum leak. LT/
WISDOMwillWIN
(Chief Bee)
06-07-03 02:00
No 438344
Post 370929 (Rhodium: "Recovery of solidified/tarry MDP2P", Newbee Forum)
Post 378106 (Rhodium: "You don't need to add DCM to be able to distill ...", Newbee Forum)
(Hive Bee)
06-07-03 18:09
No 438467
Thanx pickler, labtop and rhodium....your help is most appreciated....
lab: SWIM inspected the glass, tubing and pump...and everything looks good....SWIM just vac distilled some saf the day before this messy wacker and the saf came over at the usual 120C(like it normally does) so SWIM dunno if it's the vac....SWIM will check again though
(Stranger)
03-02-04 18:55
No 492358
having used tFSE and found this thread to be most appropriate, aproblem is presented for which any advice or suggestions would be greatly appreciated.
Vac distilled saf via 500mm vig column comes over @ 12-114 with vac utiliezed(takes a while but purity is great 1st time). Used O2/IPA wacker with 50 ML saf. Thorough clean up (ie, acid wash, DCM of aq layer, poled extracts, Bicarb wash, 2X h2o wash, NaCl wash, dried 1hr MgSo4, set up for vac dist).
The following occured: Boiling stones and stir bar were used. DCM pulled of at 40 C atmospheric for most, then under lower vac, all at 40C. Oil bath temp increased steadily (during DCM dist the oil temp was @ 60 and increasing) to 155 C. At 119-121 C flourescent yellow distillate began coming across. After only a few mils the temp dropped to 115 and dist ceased.
It wsa clear that there was further product to be extracted. The vacuum was checked and operating efficiently, no leaks, no cracks. There was little or no bumping with the spin bar going (there were a few boiling stones present for good measure). The oil temp in saf ditil was 138C and it came over at 112-114, as mentioned.
It was expected that the (ketone?) would arrive at 150-155, yet it showed at approx 120.
Now, setting aside the possiblility that the wacker was incomplete ( it is realized this is a possibility), if the ketone was present, as it seemed, what possible problems are taking place? If the sas arrives at 114, is it possible this was not ketone since the temp was only marginally above the alkene temp?
Realizing that there are many other factors at play, if it is assumed ( a foolish, terrible word in chemistry!!) all factors were corect, what can be done ?
WSill bisulfite determine ketone presence? Can a higher boiling oil be added to aid extraction?
Will bisulfite serve to ppurify it enough to salvage it?
Any input would be greatly apprecitated.
A surreal reality exists in the front of the back of our minds
(Hive Bee)
03-03-04 07:55
No 492571
What came over at 120C was probably not ketone if you are distilling safrole at 112-114c. You didnt say what your max temp was. But if you stopped at 155C you may just need to reach a higher temp. But SWIM would not recommend going over 200c. If swim missed something sorry. But hope this helps. good luck.
I think i like it!
(Hive Bee)
03-06-04 09:44
No 493371
other people have indicated that reagent grade PdCl2 is important for this reaction. also DMF maybe be a more fault tolerant than IPA.
happy shaking...
(Stranger)
03-08-04 18:49
No 493774
thanks to all who replied, your input and help are greatly appreciated.
High grade Pd was used, and CuCl2
The total O2 uptake was not properly determined in that run, as records were not kept and swim was unable to stay on top of it the whole time. The running time was approx 14 hrs.
A current IPA/O2 run has show consistent and favorable O2 uptake and should be complete shortly. Total time: 24 hrs--why so long? Just a test to see if the shake/stir repressurize technique will produce better yields. Full details will follow.
One question: if such a process were run at 47C as recommended several times, will the extended run time risk greated side products and/ or polymerization? It was understood IPA showed less polymeriztion as a solvent. Thanks to all, details to follow
why was the Reichstag really burned?