Question about performic

[raffike]

Does anything bad happens when little more(1/5-1/4 v/v more than buffered performic writeup says) H2O2 is added to rx mix.Raf mixed 125 grams of isosafrole with 350 mls of DCM and added 40 gms of NaHCO3 and stirred with overhead.Started adding mix of 150 mls of 85% HCOOH and 120 grams of 35% H2O2.When halfway thru adding performic mix,raf accidentally turned variac to full power and stirrer went mad,1/5 of the rx mix jumped out and started eating plastic.Raf cleaned mess up and added slowly rest of the performic mix to now reduced volume of rx mix.Rx itself goes like it should.Help appriciated

[lugh]

Yields have been known to bee lower when the temperature gets to high, much more useful info can bee found by

[raffike]

Temperature didn't go over 40 C since DCM was used as solvent,just little more H2O2 was used,that was the reason of this topic.Temperature wasn't problem.

EDIT:Just discovered a possible security problem.Lugh's UTFSE gif's on the net is shown thru HIVE proxy but reply mail i got contained non-proxylated image address that goes like

http://www...utfseredani.gif

Administrators might want to fix that.

[raffike]

One more question,does raf have to scale down that amount of 15% H2SO4 when he starts that hydrolysis or is amount not importnant as long as it's concentration stays same(15%).I'm not sure in that amount of iso that stayed in that flask.He started with 125 grams of iso,maybe 100 stayd in that flask after some jumped out,not sure.This situation hasn't been covered in TFSE,AFAIK.

EDIT:
PS i did found something on TFSE,somebody said using slight excess of performic got nice yields,he didn't mention how slight excess.I think raf should be fine,he doesn't scale down that amount of 15% needed for hydrolysis as slight excess of it shouldn't make no harm.Second opinion is always appriciated though...

[Stonium]

Thank you for pointing that out, raffike...and for your discretion in doing so.  

[GC_MS]

If you are worried about the temperature of your reaction mixture when applying a peracid oxidation method, then you can do the following:
*) Add the peracid dropwise over an extended amount of time, like e.g. 2-3 hours. Just extend the total reaction time a little bit.
*) Put the reaction mixture in an ice bath. No need to refresh the ice, allow it to melt. The exothermic reaction only occurs during the beginning of the reaction, and is completely finished after a couple of hours.

Concerning the sulfuric acid: don't increase the concentration. Keep in mind that sulfuric acid stimulates polymerization of your compounds and will yield you the legendary "black tar".

Hoping your reaction will end well and results in a nice and educationally enriched trip  

[raffike]

16 hour stir is over.2 layers formed.Bottom layer is kinda dark orange but clear.Upper is supposed to be water/performic.Will sepp lower layer off and see what 15% H2SO4 hydrolysis says @ 80 C and exactly for 2 hours like Ritter advised.So far so good...

PS: GC_MS,thanks for trying to help but he didn't meant to raise the concentration of H2SO4 in hydrolysis mix but rather was concerned if too much of that 15% mix would do any harm?It's probably my bad english...

[raffike]

Hive was off for some time but lot has happened in between.So raf did hydrolsysis with 15% sulfuric and 80C for 2 hours.Sepped off and tried to distill.@ 10 mm 150 degrees by C 40 mls came over and then temp went to 180 and something that solidified in condenser also started to came over,probably glycol,seems like 2 hours isn't enough,will go 3 next time.Redistilled ketone and got 36.5 grams of it.Aminated with Al/Hg and got 18 grams of white MDMA,not bad for raffike's very first Al/Hg with MDP2P.18 grams of MDMA from 200 mls of safrole doesn't sound too good but raf made lots of mistakes he won't do next time.Raf has never tried MDMA so he doesn't know what to expect,wonder what it would be like...  

[GC_MS]

[raffike]

Hmmm,wonder where did these come from.

[GC_MS]

It's normal... There is a handful of side reactions that makes they are present. Just to name one possibility: acid catalyzed cyclialkylation. In acid environments, diisosafrole (an indane) can be formed by the addition of one molecule isosafrole to another one. Another form of polymerization is photo-induced dimerization, which will yield a dimere different from diisosafrole. Etc etc. Think about it... no side-reactions would have given you 99% yield

[Rhodium]

Isosafrole glycol definitely solidifies in the condenser upon distillation, and is common as a second fraction after MDP2P (as a yellowish gel) if the preceding H₂SO₄ was incomplete. Just collect it and re-subject it to H₂SO₄ rearrangement.

1-benzo[1,3]dioxol-5-yl-propane-1,2-diol (Isosafrole glycol); physical data:

mp 102°C, bp 205°C/12mmHg¹
mp 101-102°C²

[1] Gazz.Chim.Ital.; 42 I, 36 (1912)
[2] Chem Ber 36, 3580 (1903)

[abacus]

If the mp of isosafrole glycol really is 102DegC, then someone please explain to me, why is it that my professor has heated the post performic reaction isosafrole glycol/DCM mixture to well over 100DegC to remove all DCM and then stored the orange coloured glycol in the fridge for days (many times), and it has never gone solid, ever ?

Then hydrolysis with 15% H2SO4 for 3 hours at 90DegC, ketone distilled and then animated via al/hg with no problems whatsoever??

EDit:  Am I missing something somewhere??

Abacus

[GC_MS]

Polymerization:

-

Post 409525

(Rhodium: "Why asarone cannot be oxidized with peracids", Methods Discourse)
- Friedel-Crafts and related reactions, GA Olah. II, Part 2: Alkylation and related reactions. Interscience publishers 1964. p 944-977. Of possible further interest [478: A Mueller, M Meszaros, A Karczag-Wilhelms. Ber 87 (1958) 1761]
- Photodimerization: DB Saxena & SK Mukerjee, Photooxidation of beta-asarone. Indian J Chem 24B (1985) 683-684. A load of articles can be found for other phenylpropenyl substances, especially anethole.

Or where you thinking I was pulling it from my ***?

[baalchemist]

That solidified leftover crap in the flask after a ketone distillation is often 'referred to' or 'assumed to be' a polymerized by-product of the ketone distilled. Baal took some of that solidified-tar/? and found that it liquifies around 100c, as does the glycol. So on a hunch, this hot, syrupy stuff was diluted with some MeoH and ran thru some 15%H2SO4 for 2 hours@80c. This was extracted with DCM, H2O/bicarb washed a few times,DCM was rotovapped off leaving behind a dark colored,liquid @ roomtemp. It smells like dirty ketone, and does'nt freeze, but still havent distilled yet to see what specific fractions are present in there. It definately has become a different substance than what was started with(slightly melted some plastic on contact). More investigation into mystery substance soon to follow. If this turns out to be legit ketone, then that would certainly explain what that crap actually is(not assumed) that somebees complain about cleaning from the flask afterwards. Wishful thinking maybe, but it certainly got Baals curiosity going. More to follow........

[Rhodium]

abacus: That is probably because the main product from the performic oxidation is not the plain glycol, but isosafrole glycol monoformate (formic acid ester of the glycol), see

Post 250865

(Ritter: "buffered performic -> monoformyl glycol", Chemistry Discourse). The reason that free glycol is the solid that collects in the reciever is likely due to the following reasons:

* The isosafrole glycol monoformate is thermally decomposed to the glycol during distillation
* Isosafrole glycol is less reactive than isosafrole glycol monoformate in the H₂SO₄ rearrangement, thus this compound is the one that is predominantly found unreacted after an incomplete H₂SO₄ rearrangement, see

Post 99146 (missing)

(Ritter: "isosafrole glycol less reactive than its formate", Chemistry Discourse).

GC_MS: I do not doubt that polymerization occurs, but I do not think that these products will distill in the range observed for the glycol in a relatively pure form, as well as solidify in the condenser just like predicted for the glycol.

I am very interested in your references, particularly the Ind. J. Chem article, could you post it? The Berichte article I can fetch myself, and I have the "Friedel-Crafts and related reactions" book series on the attic, so I can get that tomorrow.

[GC_MS]

GC_MS: I do not doubt that polymerization occurs, but I do not think that these products will distill in the range observed for the glycol in a relatively pure form, as well as solidify in the condenser just like predicted for the glycol.
I am very interested in your references, particularly the Ind. J. Chem article, could you post it? The Berichte article I can fetch myself, and I have the "Friedel-Crafts and related reactions" book series on the attic, so I can get that tomorrow.

You can get some polymers distilled over, although I made the mistake to assume that every newbee can pull a 0.1 mmHg "vacuum" by a snap of the finger.
The Friedel-Crafts related indanes are interesting, since it seems they are found in plants as well. I only know of one such indane been discovered up till today, but I wouldn't be surprised if similar compounds would be present in essential oils with a high propenylbenzene content (eg anise and sassafras oil). Reference: DB Saxena, Phenyl indane from Acorus calamus. Phytochemistry 25(2) (1986) 553-556. It really is nothing more then the indane arising from a condensation between 2 molecules of asaron.

[madprosr]

i believe tlc would be the best way to check if all your glycol is consumed...

but swim doesn't have plates yet, so he is wondering if he should be looking for a change from orange juice color to more of a pink/red to indicate that the h2so4 hydrolysis is done.

he has been stirring (on high) some glycol from 65g iso with 360g 15% h2so4 at 60C for almost 4 hours now, and it's still orange juice colored. hardly a hint of pink.

will let you know how it works out... tfse had nothing on "ketone h2so4 color" or "ketone h2so4 orange"

that glycol contamination sure does suck, eh bro?

[raffike]

Well i knew that glycol isn't good in Al/Hg so i redistilled ketone and didn't let temperature over 160 @ 10 mm

[madprosr]

bad idea, swim hydrolized for 6h until the mix finally took on a slightly more red-orange look. this was after a buffered performic ala Detailed Methods btw.
he used bicarb, 92% formic, and 35% h2o2 that he assumed had degraded to about 30% over 5 months. is his h2o2 too old? perhaps there was a touch of AlOH present. yes, next time he will take a freezing point on the h2o2, doh!

anyway, he cooled the soln on an icebath then poured out some really sticky orange-red ketone. he had thought it would turn red-brown when hydrolized too much, telling him to stop. but there was only a little bit of brown in the ketone which washed out easily with bicarb. for some reason, it seems to him he still has the dread glycol contamination even after such a long hydrolysis. unless the extended hydrolysis created other sticky contaminants?

at least the tone dissolved in ~220ml dcm, allowing him to wash with 3x 50ml saturated bicarb.

swim's going to try freezing out the sticky stuff and pouring off the dcm+ketone. dang it.

swim has a slow stirrer (vortex maybe 3/4" across in a 500ml rb) and he skipped MeOH in the hydrolysis, factors which could require more time. he was willing to sacrafice yields in order to make sure he converted all that damn glycol. but it didn't work.