06-12-02 23:59
No 320440
Can you hum a few bars?
Here's the lyrics.
Was once a person named SWIM,
whose chances seem none to slim.
Extracted with tolly,
some oxidized oilly
now tolly stays behind on a whim.
1. standard oxone run.
2. Used toluene to extract
3. Most comes over upon distillation, with some methanol
in there too.
4. Temp drops, but liquid is obviously much more than
to be expected.
5. SWIM's afraid of epoxide rearrangement, cuz one time
hypothesized xylene under vac at 70C which
after xylene was gone, had a dark, dark red oil,
which was probably a partial thermal rearrangement
and couldn't be put through H2so4 hydrolysis.
6. Since swim had only toll in there, swim is mystified
at why temp dropped from 110C when there is obviously
more.
And also a warning: toluene does dissolve a portion of
any sediment from the oxone which showed up upon
heating, as fine particles in the flask, but which
subsequently seemed to distill out.
????
Also swim would like a few bees concensus on epoxide
color from oxone, as it seems to vary greatly from
previous descriptions.
SWIMS after getting NP out is always a deep red/gold
color, and has heard one other say gold, but alot of
others say light yellow!
SWIM uses oxone 85/15 straight out of the bag, with a ph
of 7.
CG I miss you sweety, I really do.
(Greenhorn)
06-13-02 02:44
No 320509
Ok, humid let's see if swim can help ya. First, just filter the oxone/water/methanol to get all the sediment out before you add your iso. This will help a lot with extracting the epoxide. If you filter it, you could just tap off the epoxide if yields aren't any concern o just extract with a small amount of dcm. You'll only need a small amt because all the sediment is gone from the mix. Ditch the tolly and save it for something else. I'm really not getting what your saying on #5, but after you do your h2so4 rearrangement, it should be a dark red color. Upon distillation the ketone is a wonder color. Pickler usually gets a yellow, kinda like a morning piss after a night of drinking, epoxide. Never had any red in it. read somewhere(sorry don't remember the thread) that the red color is from safrole being oxidized by the oxone. You might need to distill your iso a little more careful.
We'll soon find out if I'm a chemist or not!
(Can't SWIM)
06-13-02 02:53
No 320514
Thanks Pickler, The iso was twice distilled on this one,
and the filter let some sediment get through, as well
swim suspects, the tolly dissolving some.
Ain't whining: just have to keep on like all the
other non-chemist bees and order more stock.
Swim hopes this one is cool.
Can't figure out how to get the remaining np out
but will try.
Thanks again.
CG I miss you sweety, I really do.
(Hive Addict)
06-13-02 06:06
No 320581
Perhaps you should try some DCM... distill if off some paint stripper if you have to. SWIC has never used toluene for extracting anything other than amine (stinks to high heaven, why would someone want to breath that in?)... DCM distills off easily and at a low temperature with a much more mild smell.
Btw, run small scale reactions with Oxone if you are having problems. There is no reason to do 100mmol scale, that's a big waste! Try 25mmol scale if you're experiencing problems (until you get your problems worked out).
(Can't SWIM)
06-13-02 13:03
No 320722
It appears that the toluene forms an azeotrope with
the epoxide/glycol (azeotrope data base confirms this).
So what could swim do now?
Is it unsavable? This is the last bit swim has.
CG I miss you sweety, I really do.
(Moderator)
06-13-02 13:33
No 320726
In Post 36700 (CHEM_GUY: "Re: benzyl chloride from hypochlorite salts", Chemistry Discourse); a procedure is given for separating such an azeotrope.
The excess toluene is distilled, and then three pints of 99% isopropyl alcohol is added (at least 1230ml), to deal with the toluene/benzyl chloride azeotrope. The toluene/isopropanol azeotrope distills at 80.6 degrees centrigrade, and then the excess isopropanol distills at 82.4 degrees centrigrade.
Since the exact composition of your mixture is unknown, one should probably use quite a bit of isopropyl alcohol
(Can't SWIM)
06-13-02 14:08
No 320729
Thanks lugh. Swim was just thinking of almost the
same thing going over the data base, but was thinking
of adding more methanol cuz toluene/glycol azeo Wt% is 6.50
while toluene/methanol azeo Wt% is 72.40.
Tol/gly bp is 110.20 meth/tol bp 63.70.
So it would appear that since swim has alot of MeOH and
the azeotrope bp is pretty low, that that would be the
way to go.
Is there something swim is missing? (besides half of her
brain for not going over the database before switching
solvents)
CG I miss you sweety, I really do.
(Title on BackOrder)
06-13-02 20:58
No 320828
I know it's not the best way to go about doing this, but on a matter of time, why not just calculate how much water is in the mix, add enough sulfuric acid to make a 15% solution, and start boiling it for three hours with good stirring? When the epoxide hydrolyzes into the ketone, the two will separate out, right?
(Moderator)
06-13-02 23:03
No 320873
The isopropanol/toluene azeotrope is 58% isopropanol, 42% toluene, while the methanol/toluene azeotrope is 72.4% methanol and 27.6% toluene, boiling at 64.7 º C; so isopropanol is more efficient, but if methanol is already at hand, it should give the same results
(Can't SWIM)
06-13-02 23:39
No 320883
Got most of it out, then dreamed of the rearrangement
which should be finished soon. Hopefully that little
bit of toll didn't hurt things.Thanks all.
CG I miss you sweety, I really do.
(I'm not Cheesie)
06-14-02 05:17
No 321015
It seems hard to get all the toluene out of the epoxide doesn't it HB? yes, DCM is the shit to use fer sure.
The Epoxide always comes out light yellow in color and upon re-distilling the Epoxide comes over a clear oil with a hint of green (only ever re distilled it once and that's what I got, vaguely greenish clear).
It sounds like you might be getting the Glycol with your darker color (dark yellow to orangey?) If you add enough bicarb to make pH7 you will yield Epoxide.
Lot's of things can make the color different. Worn out, oxidized spin bars will change your color, and other foreign shit introduced from not being clean as possible.(clean your GLASS holes!)
A cool way to add your Oxone crystal is to throw it into a tightly knitted wool sock and just dunk it and squeeze it like mad until all that's left in the sock is the Potassium Salts created by the methanol. No extra filtering needed, clean and simple. Just make sure you get all the Oxone dissolved before removing sock.(Wear Gloves)
I was once told that the red color is the color of damaged MD rings. Not good. Watch the temperature of your Oxone slurry and don't let it get past 40°C, or you will be fucked (as VL_ says). Have some ICE around to throw in just in case. Temp. should peak at around 2 hours into rxn. I have never seen the rxn get past 32°C myself. But I start with cold water at the beginning. Remember, red is bad, could be from exothermic rxn.
Bubba Fatt - LA's Biggest Bounty Hunter. His subjects are at large and so is HE!
(Can't SWIM)
06-14-02 05:36
No 321030
The real red color comes after distiling off the NP.
Befrore that it's agold color.
Regardless, swim will be hunting tommorow for shit she don't have to distill (NP).
But all signs point that hydrolysis was sucssesfull
and will be vac distilled tommorow. Have to have at least
enough out of 65gms epoxide/glycol to do a yeilding rxn.
Swim wnats the experience first and foremost.
CG I miss you sweety, I really do.