Author Topic: Cleaning-Up Isosafrole  (Read 2585 times)

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Bwiti

  • Guest
Cleaning-Up Isosafrole
« on: April 24, 2002, 05:15:00 AM »
In my dreams, a squid-like alien creature contacted me. It said that communication while humans were in a dream-state was easier, because our disgusting egos get in the way less than when we are concious. It said that it would help us abolish drug-control by giving all federal employees rectal cancer if I can help it with a chemistry problem. Here's what it said:

"I added calcium oxide/KOH to sassy oil, then refluxed for a few hours, and now it's time to clean-up the isosafrole, which is a uniform light tan color. I've done several dH2O washings on this, and even tried washing with HCl, but it's the same damn color. Besides distillation, what else can I do to clean this stuff up? Without a vac-pump, I'm afraid to distill, so I have to make the best with what I have. Yes, I'm a poor alien; spent all of my cash on fixing up my ship, and various interesting drugs. I want to put my tentacles into your brain, so you can see the world as I do....." 8)

Love my country, fear my government.

Belial

  • Guest
Filter
« Reply #1 on: April 24, 2002, 08:58:00 AM »
Vacuum filtering is very effective in cleaning up the product of this isomerization. SWIM follows her Eluesis devotional bible and vac. filters then distills. Although you state that you dont have vacuum! so this could be a set back. and why are you afraid to distill? Atmospheric is fine here

humidbeing

  • Guest
iso safrole
« Reply #2 on: April 24, 2002, 02:08:00 PM »
Bwiti, just run room temp water through the condesor
 and runn stirring to avoid bumping, then just distill
at atmospheric.
 The tan color worries me though. Should be much darker.


CG I miss you sweety, I really do.

cheeseboy

  • Guest
tan?
« Reply #3 on: April 25, 2002, 01:23:00 AM »
Yes, the color of Isoasafrol from the isomerization is a dark brown. Maybe the CaO does something to the color.

May De Sorce Bee Wit Chu-Always

metwurst

  • Guest
perhaps dark tan
« Reply #4 on: April 25, 2002, 06:47:00 AM »
Bwiti, was isomerization performed on sassafras oil or on safrole distilled from sassafras oil? If the alien used plain sassafras without any form of clean-up, this would probably explain the difference in color, and almost undoubtedly has negatively effected yield.
Isomerizations carried out on fractionally distilled safrole using KOH and CaO in this neck of the woods all yield a dark brown oil. When this is vacuum filtered, the resultant oil could be called "dark tan", but one's first choice of a name for the color would be brown.
TFSE suggests vacuum isomerization with anhydrous KOH yields better than CaO/KOH isomerizations.
You should distill your isosafrole to purify it, separating unreacted safrole from isosafrole, and leaving behind reaction by-products. Proceeding without distillation would seem to be undesirably "ghetto", and is going to throw stones in your path.

Bwiti

  • Guest
"was isomerization performed on sassafras oil or ...
« Reply #5 on: April 25, 2002, 08:11:00 AM »
"was isomerization performed on sassafras oil or on safrole distilled from sassafras oil?"

  Well, at least it was washed with a solution of NaOH, then dried with Mg-sulfate. Also, I'm slightly color-blind. :P

Love my country, fear my government.

zooligan

  • Guest
iso distillation
« Reply #6 on: April 26, 2002, 12:34:00 AM »
Perhaps living underwater your squid friend overestimates STP (standard temp/pressure).  However, on the crunchy crusty surface of the planet, with only the atmosphere exerting its force upon our bodies and distillation rig contents, a STP distillation of iso is nothing to be scared of.  Peanut oil as a buffer will result in crystal clear iso from fractional distillation, with all the brown yummy scuzz left in the buffer oil.

No shit.  Really.

z

"No one can build his security upon the nobleness of another person." -- Willa Cather

Bwiti

  • Guest
Peanut oil? Is this watched?
« Reply #7 on: April 26, 2002, 09:52:00 AM »
Peanut oil? Is this watched? ;D  Alright, he'll give that a shot. He'll also add some broken chips of glass to give it a more uniform boil, so oil won't splatter all over the kitchen again. 8)  

Love my country, fear my government.

Rhodium

  • Guest
Buffer oil
« Reply #8 on: April 26, 2002, 12:46:00 PM »
I thought we all agreed in a recent dicussion (UTFSE) that buffer oil was unnecessary, and just an urban legend started by Eleusis?

riobard

  • Guest
addressing peanut oils and colors....
« Reply #9 on: April 26, 2002, 06:03:00 PM »
The peanut oil people bring up can be found near the turkey fryers in that Orange Warehouse everyone goes to for home related items in the US, at least in SWIM's market in the south. It is completely unnecessary though, but i guess one could eek out every last drop of non polymerized isosafrole and safrole forerun by using it to drive out the lower boiling good stuff. Your reaction color seems like bad news to me. Swim's atmospheric without Cao was dark brown, almost black. With the CaO, you should get that dark color with even more insoluble crap in the bottom of your flask. The KOH makes the color, the CaO takes up the moisture to ensure reaction progress. Distillates should be clear in color, and can be done at atmospheric pressure.

goiterjoe

  • Guest
don't buffer essential oils
« Reply #10 on: April 26, 2002, 09:54:00 PM »
Buffering essential oils for distilling has always spelled disaster from my experiences.  I was never able to reclaim my attempt at TMP2P due to buffering, and my only botched peracid synth came about after buffering the ketone and then trying to vacuum distill.  Maybe it was because of the oil I used, but it seemed to hold the oil in for an extra 30C or so without letting it distill.

Chromic

  • Guest
Agreed!
« Reply #11 on: April 26, 2002, 10:31:00 PM »
Agreed, use no buffer oil.

Rhod, you should update

https://www.thevespiary.org/rhodium/Rhodium/chemistry/peracid.html

to reflect that... where it says:

Dry organic phase over 50g of anhydrous MgSO4 (made by baking epsom salts at 300°C for a couple of hours, let cool, then grinding into a powder) making sure to filter off the MgSO4, and washing the filter cake with a small amount of DCM. The solvent is removed and kept for a later run, the resulting residue is combined with 100ml of vegetable cooking oil and distilled under vacuum to yield ketone (>200 grams) [That is a 56%+ yield].

It should read:

The DCM is quickly distilled off with no vacuum and kept for a later run, the resulting residue is then distilled under vacuum to yield ketone (>200 grams) [That is a 56%+ yield].

There's no reason to dry DCM before distilling (water is azeotropically removed), and there is no reason to add a buffer oil to ketone (if it's polymerizing, that's because your vacuum sucks).

Rhodium

  • Guest
DCM/H2O azeotrope?
« Reply #12 on: April 26, 2002, 10:38:00 PM »
Sure - I'll remove the cooking oil part - but what about that azeotrope? Composition/bp? I am very fond of always drying my non-polars before evaporating the solvent in all reactions - are you saying I'm wasting my time?

Osmium

  • Guest
No! Dry it! The DCM/H2O azeotrope contains only ...
« Reply #13 on: April 26, 2002, 11:20:00 PM »
No! Dry it!
The DCM/H2O azeotrope contains only very little water. When you distill ketone without drying there will invariably be water present, which will cause the usual problems (bad vacuum until it is all gone).

I'm not fat just horizontally disproportionate.

zooligan

  • Guest
buffer oil
« Reply #14 on: April 27, 2002, 12:59:00 AM »
I dunno, maybe it is unnecessary, but it sure helps when it comes time to clean out the flasks.  It holds any leftover crap in suspension instead of polymerizing/carbonizing it on the flask walls...

z


"No one can build his security upon the nobleness of another person." -- Willa Cather

goiterjoe

  • Guest
acetone does that just fine
« Reply #15 on: April 27, 2002, 02:48:00 AM »
There isn't anything left over after distilling ketone that a couple washes of acetone won't cure.  If you still have some gunk at the bottom of the flask, KOH in IPA or just hot NaOH solution soaks will finish up the job.

Bwiti

  • Guest
Thanks!
« Reply #16 on: April 27, 2002, 05:24:00 AM »
Thanks for the heads-up folks! In my dreams, I was into PCP-analogs for so long that when a technique was questioned in the phenethylamine world, I wasn't there.

Love my country, fear my government.

dr_ruthenium

  • Guest
Safflower oil
« Reply #17 on: April 28, 2002, 10:29:00 PM »
I understand the use of a buffer oil to try to avoid scorching/carbonization/polymerization and the cons.  Any idea if using safflower oil as buffer could f'up the ketone?  Could this be cause of my failed amination?

Rhodium

  • Guest
Buffer oil
« Reply #18 on: April 28, 2002, 10:58:00 PM »
Yes, possibly. The buffer oil is not necessary at all - the only thing it might help with is easier flask cleaning, while the problems it may cause are unknown.

dr_ruthenium

  • Guest
Has anyone experienced failed amination with ...
« Reply #19 on: April 28, 2002, 11:05:00 PM »
Has anyone experienced failed amination with ketone distilled with buffer oil while keeping all other parameters from successful aminations constant?  Rhod, PLEASE check out my post "Amination Failure" in Newbee Forum.

LaBTop

  • Guest
Rhodium,
« Reply #20 on: May 04, 2002, 07:01:00 PM »
You still have this hanging in your Chemicals section of the Peracetic :
Distillation:
100ml of Cooking oil to prevent scorching

And YES, it must be clear now for all beginners that use of any additive in the form of another high boiling oil like peanut oil or damm whatever is totally nonsense.
It gives way to that fine possibility of carbonizing a futher perfect batch. LT/

WISDOMwillWIN

Rhodium

  • Guest
Error fix
« Reply #21 on: May 04, 2002, 09:00:00 PM »
LT: Thanks - I missed that. Now it is all corrected.

dr_ruthenium

  • Guest
Rh: Can I blame all of my failures on you- having ...
« Reply #22 on: May 04, 2002, 11:14:00 PM »
Rh: Can I blame all of my failures on you- having used a buffer oil while distilling safrole, iso, and ketone (trifecta)?!  Guess that I would have to give you credit for all future success too... Dr. Ru

LaBTop

  • Guest
No, you can't.
« Reply #23 on: May 05, 2002, 04:46:00 AM »
Rhodium collects all these goodies as some sort of super librarian for underground chemists, because no one else seems to do it at this level and scale. That means that he gathers all really interesting posts or threads in our forums, and can't be held responsible for small typo's, mistakes or even sometimes blatently wrong pieces of postings. You have to address that to the poster.
And those will do this also not willingly, they just follow a slowly introduced hoax or mistakenly copied piece of info from the web or whatever other kind of bad info.

That's why you need to dig deep on the Web or better in the libraries, when you follow a posted method and engage strange anomalies which can't be explained by your own mishaps.

In your case I don't think that that bit of peanut oil is the culprit, you will probably have encountered the chem fairy, that nasty little bitch, who influenced your thoughts and let you make the same mistake multiple times.
Only time will tell, and a lot of repeated batches, as usual.
Please don't be shy to report the real mishap, so everyone can learn from that.
The bravest scientists are the ones who can admit a mistake, and correct it publicly. LT/

WISDOMwillWIN

Bwiti

  • Guest
$$
« Reply #24 on: May 05, 2002, 07:07:00 AM »
"Only time will tell, and a lot of repeated batches, as usual."

  Lots of ideas/desires, but little money is my problem.
:(

Love my country, fear my government.

metwurst

  • Guest
More on tan oil, maybe even the answer
« Reply #25 on: May 06, 2002, 04:35:00 PM »

As part of an isomerization experiment, 100.6 g of safrole (fractionally distilled at STP) was placed in a 250 mL flask. 1.2g of 90% KOH was added.
The flask was heated to 100°C at 60kpa (~450 mmHg) to drive off water, then a condensor was fitted for reflux.
Temp was brought up to 110°C, and the setup was left to react overnight at 60 kpa.

Approx 14 hours of heating later (reflux did not occur, and this was deliberate) the flask was left to cool.

A small quantity of the resultant oil was removed. The oil was a nice light tan color. A boiling point test was performed with the thermometer 5 mm above the surface of the liquid. (A beautiful condensation/thermal inversion effect was noted. Very pretty, if inconsequential) Boiling point was established to be 235°C. Boiling point of the distilled safrole using the same setup was previously established at 232°C

It is apparent from this that very little isomerization - if any - did occur. metwurst could have perhaps looked this up, but felt inclined to try it anyway: Practice makes fairly good.
In any case, if the oil is light tan, then metwurst would suggest no isomerization occurred.

The flask was then vacuum refluxed for 4 hours at ~130°C at 95 kpa, which resulted in 92.4 grams of isosafrole after distillation. metwurst supposes some of the safrole decomposed during the long slow heating.

Rhodium

  • Guest
bp measurement
« Reply #26 on: May 06, 2002, 06:19:00 PM »
A boiling point test was performed with the thermometer 5 mm above the surface of the liquid.  Boiling point was established to be 235°C.

You cannot measure boiling points like that, your reading would still be ~232°C or slightly above even if you had 95% isosafrole and 5% safrole, as the safrole boils first of the two and is thus the only compound to reach the thermometer.

Chromic

  • Guest
More on isomerization
« Reply #27 on: May 07, 2002, 01:27:00 AM »
You must fractionally distill the isomerized sassafras to get a good idea of the BP.

You should be making laboratory notes that look like this:

May 6, 2002: safrole (100.0g, frac of sassafras oil, BP 230-234C) was refluxed with flake potassium hydroxide (1.5g) for 12 hours at 160C reflux. The color of the reaction turned from an light yellow to black, as per usual. Fractionally distilled contents of flask at atmospheric pressure:

(100C-230C) 1.0g brokedown safrole
(230-250C) 2.0g unconverted safrole
(250-254C) 94.0g isosafrole
(>254C) 3.0g undistilled crap in flask / losses

Then you discard the brokedown safrole, store the unconverted safrole (to add it to future isomerizations), then use the isosafrole for making ketone, and throw out the rest... you also get a good idea of where you went wrong etc, and if you post information like that to the hive, everyone will be more than happy to help you out!!

metwurst

  • Guest
bp measurement?
« Reply #28 on: May 07, 2002, 07:36:00 AM »
You cannot measure boiling points like that, your reading would still be ~232°C or slightly above even if you had 95% isosafrole and 5% safrole, as the safrole boils first of the two and is thus the only compound to reach the thermometer.

Interesting, and thanks for the clarification.
Have you any ideas on how I reached 235°C then?
Further detail:
The thermometer was suspeneded 4.5 - 5 mm above the surface of the oil in a duran test tube.
The impatient metwurst carefully brought the soil to boiling point using a butane torch.
A very gentle simmer was maintained with the butane torch in a stationary position.
The thermometer temperature rose from about 12°C above ambient to 228°C over the course of 75-80 seconds. This rapid rise began several seconds to the first bubbling of the oil.
3.5 - 4 minutes after boiling began, the temperature began ro rise. It fluctuated between 234°C and 236°C. I chose the approximate temperature of 235°C to report.
When the temperature failed to climb above 236°C, metwurst presumed insignificant isomerization had taken place, and that an azeotrope of safrole and isosafrole was the cause of the slightly elevated temperature.

Is this thinking incorrect?

I think this might be the point where I'm chastised for a) not using an oil bath to ensure temperature regulation and b) being presumptuous.
If so, I humbly shoulder the mantle of blame.