LWR post rxn ratio questions

[jammin]

Finnaly my friend did finnish his LWR.
It stood for about 48 hrs with the following ratio

11g   E.HCl
13.2g I2
5.5g  rP
8.8   dh20

Placed in oilbath @ 120 <-> 130C (oilbath temp) for about 48 hrs.
NP Solvent of choice: Toulene


Took of condenser and boiled off remaining iodine for 15 min.
Added 30 ml h20 to rxn fluid. Water turned milky orange just as some bee said.
rP fell to bottom like bricks after swirling. He then prewetted filter with dh20
and filtered the rxn fluid.

Then he added 20 ml to rxnbottle, swirled, and filtered this into the 30 ml he already had.

Time for NP washes.
2 x 50ml and one 100ml. NP looked pissyellow.
But he knew it was iodine as he has been there before and panicked...

Read ph, was between 0 and 1.

Added NaOH sullotion and checked Ph; around 5.
He based some more until no more colorchange cold be seen.
Checked PH again 15.

Seemed like meth oil floated on top, cause he saw a yellowish layer on top.
It could also be poorly decanted np with i2 in, but he didnt think so.
Layer was about 3ml in a 250ml beeker.

Aqua-layer started to semi-solidify, added some hot dh20.
Worked like a charm.

Started np-extraction.
Added 200 ml np.
Sepfunnel only 100ml, so he had to use a bottle to shake and carefuly decant.

He shook like hell, let sit for 15 min and decanted.
Repeated this three times.


Now he was left with 600ml np solvent.
Read geez's wonderful post, and tried to extract with 3x125 ml dh20.
Lost his dammed pipette so he measured HCl by ml.

He added 5 ml hcl on the first extract.
Shook, let sit 15 min, decanted and checked PH.

Ph was around 7.

Added 2 ml hcl on next 125ml dh20 extract. Ph was now way down to about 3.
Shook, let sit 15 min, decanted.

On the last extract he only had a few drops of HCl.


Finnaly he was to evap. the h20.
This took quite some time, and when he looked for crystals to form, there only
came a yellow sludge that never wanted to crystlize.

After some time he decided to try to flood with acetone.
This worked somewhat and removed the yellow acid remains.

He filtered the tone, and was left with some white powder.





Yeilds however where devastationly low.

He wondered if he used the right volumes for extractions.
Like for instance; should he really use 3x200 ml of NP to extract amines?

If you bees have any tips on increasing yeilds he would be forever grateful!





Thanks to geez, wareami and all you others that helped him out this far.
He is forever indebted to you all!

[Osmium]

> Took of condenser and boiled off remaining iodine for 15 min.

There is no iodine left, and even if there was you wouldn't be able to remove it like that. And even if you could this is totally unnecessary, all you did was boiling HI out of the flask which will colour your walls yellow and corrode the shit out of everyting that's made from metals.

> NP looked pissyellow.
> But he knew it was iodine as he has been there before and panicked...

If you had evapped the washes you would have realised that this yellow stuff isn't iodine. Iodine in NP solvents is colored purple, sometimes brown.
Do 3 washes. You can also use other amounts of NP solvent, e.g. 50-30-20ml.

> Started np-extraction.
> Added 200 ml np.
> Now he was left with 600ml np solvent.

WAY too much! Again, doing 3, 4 or maybe even 5 extractions with much less solvent (e.g. 30-20-10-10-10ml) would have been better and eventually higher yielding.

> Finnaly he was to evap. the h20.

You should have gassed it. Gassing 6 or so grams of chili in 600ml of solvent is of course ridiculous, but gassing 6g of freebase in 60ml or so of NP solvent isn't.

> Yeilds however where devastationly low.

How low?

> should he really use 3x200 ml of NP to extract amines?

Only when you have a rotovap and can easily reduce the volume of solvents for the final crystallization.

[jammin]

>There is no iodine left, and even if there was you wouldn't be able to remove it like that. And even if you could this is totally unnecessary, all you did was boiling HI out of the flask which will colour your walls yellow and corrode the shit out of everyting that's made from metals.

Ok, he was told it was. He just ordered sodiumthio to removed but it hasnt arived yet.
Someone told him just to fuck it and proceed. It would be removed when he based it.

The strange thing is that it seems to be i2, cause the shit just wont come out. He did plenty of washes last time he tried. And the discoloration never stopped.. After he based (adding NaOH, thus forming NaI?) the color vanished, just like that...

>If you had evapped the washes you would have realised that this yellow stuff isn't iodine. Iodine in NP solvents is colored purple, sometimes brown.

hm.. pissyellow was perhaps an understatement.
I was rater more like dark beer, an orange-browinsh thing.
It became more dilute when washed but never ever gave up.

>Do 3 washes. You can also use other amounts of NP solvent, e.g. 50-30-20ml.

Ok, he will do that next time.

> Started np-extraction.
> Added 200 ml np.
> Now he was left with 600ml np solvent.

>WAY too much! Again, doing 3, 4 or maybe even 5 extractions with much less solvent (e.g. 30-20-10-10-10ml)
>would have been better and eventually higher yielding.

Ahh.. Great. He figured this had to bee to much.
He must have misunderstood some elderbees post.


>You should have gassed it. Gassing 6 or so grams of chili in 600ml
of solvent is of course ridiculous, but gassing 6g of freebase in
60ml or so of NP solvent isn't.

He will make a gassing apparatus as suggested.


>How low?

About 2g. But in his defense he had a minor spilling accident.


>Only when you have a rotovap and can easily reduce the volume
of solvents for the final crystallization.

Well, have to wait until next week to buy one of those...

[geezmeister]

How much np solvent you use to extract has to be related to the size of the reaction. The post reaction workup posts I made were based on my typical experience, and my usual reaction at the time I wrote those posts was about 28-36 grams of pseudo HCl. Its hard to mention everything, particularly when you mention (as Os pointed out) far too many things.   

[place]

If you don't steam destil., then do the keypluking methode insted of a regulary a/b.

WAY too much! Again, doing 3, 4 or maybe even 5 extractions with much less solvent (e.g. 30-20-10-10-10ml) would have been better and eventually higher yielding.

Is around 60mL NP really enough to extract maybe 8g of Chili?


You should have gassed it. Gassing 6 or so grams of chili in 600ml of solvent is of course ridiculous, but gassing 6g of freebase in 60ml or so of NP solvent isn't.

Do gassing inprove the quality/yield so much, compare to make crystals with HCl water?

Thanks   

[kris_1108]

[place]

[place]

@jammin: Have you found out the reason for the small yeild?

[jammin]

But i think it might have to do with impatiance whilst doing the AB.

I read that the process was not instantainious, but swim only waited for like 5 minutes.

Then he also noted another thing yesterday. When you are titrating the basic NP layer dont take the PH right away.

Shake good and then waith at least 5 min to take the PH.

Geez and someothers suggested to add 10 drops of HCl in 75ml of water and axtract with this. Repeat until no more goods are transfered.

This could take a some runs if you overbasified the NP layer, but at least you'll get your goods!

Swim tried this on a NP-layer of E.HCl he had saved, 2g jumped out...

Remember to let the sollution stand for at least 30 minutes pr extraction. At least thats what i learned....

[ChemoSabe]

In swims buddy's version of the ker plunk method of basing just one large volume (300ml) of hot naphtha is used for all extractions. An initial portion (200ml or so) of the naphta is decanted off for titration or gassing after the finished ker plunk process has cooled for at least 15 minutes. The portion of naphtha left to remain in the flask usually stays there for about 6 hours to suck up what else it can of the freebase.

The latest gaks seem to possibly have NaOH (or something about the water layer) hanging on to some of the yeild most likely due to 'amphoteric' reasons. Swims buddy recently checked a flask from 2 months back which still contained the lye water and naphtha from an old rxn which had previously given it's all only to find an unexpected fishy odor and a bonus mystery gram within assumed to have been eventually released by the Lyewater layer.

PS. After the first portion of naptha taken has given it's goods it's usually put back into the ker plunk flask to make for easier decanting. Only for the very last extraction done is the naphtha fully poured off from the flask. Doing this minimizes the amount of garbage brought over from the lye water and it also makes the water washes done to the naphtha much easier to perform.