Author Topic: Dr Drool method Viable? (Read 2303 times)

myhero · « **Reply #80 on:** March 08, 2013, 10:14:23 AM »

I ve just finished a performic acid oxidation on 300g Isosafrole, I will be isolating the glycol by distilling the DCM next week. I am always skeptical at the orange color of the organic layer after the oxidation step. The oxidation was let run for around 20h. Only at the beginning (during addition and a little later) reflux was seen, the reaction subsided and by the next morning temp was down. Everything was left to stir anyway for the whole day. Here is a picture of the two layers still separating in the the flask after stirring was stopped at around 20h.

pb interger do you recognize the colors? was your organic layer darker? As I said I am always skeptical about this. Last time I had some forerun of I believe isosafrole after hydrolization.

Last time I tried this I had issues with the concentration of the H2O2. This time I used 35% H2O2 and I used a little more to be sure. (CALCULATED AS IF IT WERE 33%)

I ll let you know any progress, once I get to the next step.

ImAMANGUYS · « **Reply #81 on:** March 08, 2013, 02:51:35 PM »

Sup MyHero,

Couple of things:

You might want to blur those glass reflections and all fingerprints and reflections have been used as evidence. These are things they can lift off pics and good reflections. Please do this asap!

Secondly, the colors look alright. Is your organc layer on the bottom? It should be. I've only performed the peracetic where you get yellow organic layers but tht looks typical of performc reactions ive seen. How easy did that emulsion seperate? Perhaps evap the dcm and retake the picture of the glycol...

Another thing is that you dont have to purify the intermediate glycol/epoxide. You said u had forerun of isosafrole. If you're going for purity all for you though man

Keep up the good work!

pbinteger · « **Reply #82 on:** March 08, 2013, 03:26:18 PM »

Hello,

The color looks fine for the dilute glycol. I've had varying results with 4 different performic oxidations, and the concentration of H2O2 is a factor as you've said. I just ran one the day before yesterday and it was much lighter than that -- it did end up being a dark deep orange, bordering on red, color after removing the DCM. I've also had an organic layer that was darker orange. It produced a 70% yield of MDP-2-P even considering the lighter color, which concerned me initially. My H2O2 was certainly at the point of expiry so I've ordered a fresh batch. Your color looks good to me -- and I think you'll get at least a 50-60% final yield of HCL if you move forward from here. The only time that this reaction failed for me was when I attempted it with safrole that had not been successfully isomerized, and it produced a vastly different result. My organic layer was on top and the color was very pale light yellow.

I feel like if this reaction is a complete failure you will absolutely know it.

Onward! Great Work!
Keep us posted on yields!

_Pbint_

newbiechem · « **Reply #83 on:** March 08, 2013, 04:45:55 PM »

Quote from: ImAMANGUYS on March 08, 2013, 05:53:17 AM

Quote from: newbiechem on March 08, 2013, 05:18:38 AM
Quote from: jon on December 30, 2012, 10:56:41 PM
yeah but that's just isosafrole at 89% by the time you get through all the other steps it's more like 70% overall and it's a big pain in the ass.
so i like 3 simple steps and no distillations and 90+ % yeild you can't beat that.

wow what method is that?!?!?! hehehe 3 steps, and NO DESTILATION?? im the only one never heard that?

Let me direct you away from it. Though it works (backed by literature), it is difficult to get consistently high yields with it: trust me on that one. Too little too many times, But others might disagree.

If you won't believe me the method is called either the "bromosafrole" route, or commonly known in this forum as "Jon's Route."

Check it out though, learn about all the chemistry you can

oohhhh ok

Jons method! of course ive read it!!!! has also something on strikes book if im not wrong....?
i read couple things on it, but nothing that seemed a true shot, i remeber reading somewhere, someone gassing safrole with bromo......

i though you guys were talking about reaction of Mdp2p of 90% yields and no destilation hehehe

i think thats why havent tryed yet, not sure it works hehehe

maybe will give it a try after ongoing project...

peace!

pbinteger · « **Reply #84 on:** March 20, 2013, 12:16:22 AM »

ASsyl

I tried your technique
The results were very pleasing!

I'm going to work on improving removing all the solvent under vacuum in cold conditions -- they came out with a bit of a residue on them -- it would be BEAUTIFUL to see them crystal clear with no little bits of hair from the air on them....

Picture is attached

EMTWC · « **Reply #85 on:** March 20, 2013, 02:52:40 AM »

SHARDS!

myhero · « **Reply #86 on:** March 20, 2013, 01:58:11 PM »

ImAMANGUYS,

organic was on the bottom and no i did not purify the glycol. What I meant is that last time I had some some iso forerun after hydrolization, because of weak H2O2. This should be fixed this time. Will update on results.

myhero · « **Reply #87 on:** March 20, 2013, 02:36:35 PM »

guys when you're talking about yield are you talking molar or weight ?

myhero · « **Reply #88 on:** March 20, 2013, 03:34:54 PM »

I will split the batch in two like OcoteaCymbarum: 2 smaller hydrolizations because of glassware size. I don't want to buy anything bigger than a 2L for now. I will also do the washings separately as to be able to perform them with good glassware.

I have read of someone performing the hydrolization without MeOH and I quote

I have read that it can be performed without MeOH as in this post by placebo from the same OC thread on the Hive:

Quote

SWIM did 1kg performic, and used 3L 30% HCl so that it would fit into 5L flask (no MeOH). That amount of HcL was approx half what there should have been (IIRC), so SWIM ran it 5 hours (was going to run 4 hours but fell asleep) and got 72%/mol or 80% by weight, which is what you got.

He say she using half the HCl, but in reality he is using half the HCl with 2 times the strength (i.e. 30%). Would that be a viable way of saving flask space and be able to process more at the same time.

ImAMANGUYS · « **Reply #89 on:** March 20, 2013, 06:18:29 PM »

MyHero,

Different people with diff background post yields differently. I believe PB wiuld post in molar yield but you'd have to ask for clarification if you want to know. The correct scientific way to do it is molar. Weight is for laymen.

I think the reason noone has answered your post about the hydrolysis without solvent is because noone here or at the collective has experimented with it... Then again maybe its a well kept secret

but in theory The methanol regulates temps and makes the glycol/epoxide more miscible with acid. Do you wana give that up?

Why dont you try and tell us

experiment is king the saying goes...

As for the isosaf forerun, its never happened to me. Ive had luck with my hydorgen peroxide concetration and other reagents. Let us know if your revisions fix the problem and if not pm me and well figure it out.

ImA

myhero · « **Reply #90 on:** March 21, 2013, 10:19:26 AM »

Hey. I have run the Rearrangement on 222g of Glycol (half of what was produced by a 300g Performic) with

270ml MeOH
450ml Water
440ml 33% HCl

After 2.5h @ 80°C he cooled everything down, separated the bottom layer (impure ketone), extracted thee upper layer 3 times with DCM (100ml, 100ml, 70ml, maybe overkill).

Then I washed the DCM extracts 400ml 5% NaOH and I got a nasty milky emulsion which turned most of the DCM into this milky thing. Previous times I used Toluene for this step and I didn't have this issues.

I separated the NaOH which was red then quickly turned black. Then I washed the DCM/Emulsion multiple times with dH20. I saved both the NaOH wash (in freezer) and the water washes since I plan on back extract them. The last water wash was almost neutral (ph6).

I was left with with around 330ml of DCM extract. Considering I used 100+100+70 plus the ketone it seems a litttle on the low side....

I ll revert when I have more data.

ImAMANGUYS · « **Reply #91 on:** March 21, 2013, 03:47:45 PM »

Wow that does seem low

some advice myhero:

Make sure you take ample time to let your washes separate here! Especially the NaOH ones.

One thing I've noted is that, with the DCM and NaOH the emulsion is formed. That cloudy thing you got is normal. Wait till it clears up the best it can. If your NaOH layer is black or dark red, that's because there's still alot of product in there. The best thing I've found to do is, even before back extracting, is To place the wash in a sep funnel and let the DCM separate out (in the freezer if possible). You'll find you can probably separate off a few milliiliters of product as a blackish mass several times before even running DCM extractions. Just wait till some black mass forms on the bottom, sep it off, wait for more to sep out, sep it off. This will definitely improve yeilds but you've got to be patient. It may take a half an hour between seperations. Shaking helps the layers separate. I've found that you'll still have to wait for this to happen even if you DCM extract so why not just save your precious chems till the solution is mostly clear of the blackish red color?

Goodluck

ImAMANGUYS · « **Reply #92 on:** March 21, 2013, 07:14:07 PM »

Also, its not uncommon to still have a bit of dcm and side products as part of the glycol mix even after the glycol is assumed pure! This may be pushing u to assume lower than average yields

Just a thought! Get back to us after your backwashes and results!

myhero · « **Reply #93 on:** March 22, 2013, 10:22:56 AM »

I saved all my washes.... I have already back-extracted the water washes and the NaOH washes. The latter is now sitting in the freezer waiting to be separated (next week) and maybe back-extracted again. Then I ll proceed water washing all these DCM extracts and distill. Last time I used Toluene I had none of these issues.

About the dark color of the NaOH wash. I though it was supposed to be black, regardless of trapped product.

ImAMANGUYS · « **Reply #94 on:** March 22, 2013, 11:20:56 AM »

At least for me, if the layer is still blackish red then more dcm/crude ketone can be separated off. At the end the water layer looks orangish... I cant speak for us all just my 2cents.!

pbinteger · « **Reply #95 on:** March 22, 2013, 03:21:25 PM »

Yea those pesky chlorinated hydrocarbons don't play well with Na cations....

I see no problem with using Toluene, Xylene, or Ether for this step whatsoever....

myhero · « **Reply #96 on:** March 25, 2013, 09:28:39 AM »

maybe you got me wrong. I extracted with DCM after the hydrolysis3 times. So I am sure that the DCM had all the goodies in there. The problem arose when I washed the DCM with dilute NaOH. What I am doing now is backextacting the NaOH. I ll keep you posted.

ImAMANGUYS · « **Reply #97 on:** March 25, 2013, 11:43:59 PM »

Quote from: myhero on March 25, 2013, 09:28:39 AM

maybe you got me wrong. I extracted with DCM after the hydrolysis3 times. So I am sure that the DCM had all the goodies in there. The problem arose when I washed the DCM with dilute NaOH. What I am doing now is backextacting the NaOH. I ll keep you posted.

Myhero, pb had you understood perfectly well... DC(hloro)methane IS a chlorinated hydrocarbon

hes suggesting that you use a different nonpolar for extraction after hydrolysis if planning an NaOH wash as the Na ions form emulsions with DCM.

And i was speaking on the back extractions as well. If your NaOH washs are dark then they have product in them. Period. You may only need to back extract once if u wait long enough for most of the product to separate out.

myhero · « **Reply #98 on:** March 26, 2013, 01:48:22 PM »

OK I understood the DCM issue. I used toluene myself and it worked without problems before. I will back extract the NaOH layer and see what happens. I hope I can get more product out of it...

Alternatively next time what kind of washing do you suggest ? Plain distilled water? Sodium Bicarbonate?

myhero · « **Reply #99 on:** March 28, 2013, 04:01:30 PM »

I processed the remaining glycol. After the hydrolization the lower dark layer was separated and the upper layer extracted 3 times (100, 100, 70ml) with DCM Then this layer was washed with plain demineralized water. This created no emulsion, but did not particularly take away any dark color from the crude ketone in DCM (just a little). The organic layer became more brownish (a bit more clear brownish). The water layer was not particularly acidic, kin fact some Sodium Bicarbonate was successfully used to neutralize the little acid present. The organic layer was set asid for now just after one wash and will be taken out in 10 days to proceed with more washings.

Question is are they really necessary?
is it okay to skip the NaOH was and only do water washes?
Can the NaOH wash exchanged with Sodium Bicarbonate was?
Is the Brine was necessary considering we will distill?

I also back-washed 2 times the old NaOH wash from the first half batch and got some dark DCM out of it. Hopefully 2 times was enough. I saved each and every wash just in case anyway and I will pool them all together and do a final backwash. I Hope I got all the goodies out. I ll only know when I do the distillation in 10 days time.

Author Topic: Dr Drool method Viable? (Read 2303 times)

myhero

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ImAMANGUYS

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pbinteger

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newbiechem

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pbinteger

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EMTWC

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myhero

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myhero

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myhero

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ImAMANGUYS

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myhero

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ImAMANGUYS

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ImAMANGUYS

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myhero

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ImAMANGUYS

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pbinteger

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myhero

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ImAMANGUYS

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myhero

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myhero

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