Post Benzo-Wacker HCL Flooding

[Potential]

Alright...first Benzo-Wacker as per Methyl Man's writeup.  Six hour prestir of PdCl2 in Methanol then addition of Safrole and d-H20 over 1-1.5 hour.  Heated reaction to about 65 degrees and kept at mild reflux for 8+ hours.

Now...when it came time to flood the reaction with 6N HCl sol'n, much to my chagrin, I had only 300ml of muriatic (instead of 500ml) to add to 1150ml of d-H2O.  Nonetheless, I plowed on, extracted with DCM (500ml, 300ml, 200ml)did the bicarb washes (2x 500ml), NaOH washes (2x 500ml), and d-H2O washes (3x 500ml).  Dried with MgSO4 then distilled off the DCM...something peculiar happened.  I only recovered about 50% of the DCM.  Moreover, when I distilled the ketone (neon green/yellow) there was very little safrole that came over before.  Total ketone:  50-60ml  I'm guessing that the safrole ketone conversion was good but I lost half of the product somewhere...WTF?

(By the way, I saved the post Wacker solution that I extracted with DCM)

[OcoteaCymbarum]

is that what you mean? You extracted, for example with 500, 250 and 100 ml for a total of around 850ml then recovered only 450? Dont worry about that too much, as you loose tons of dcm very easily having such a low boiling point.

It could also be, and most likely, that you still have a lot of dcm in your washes. Especially with water washes.

What you should do ic combine the 2 water washes, put them back in the sep and get more dcm out. Sep out, leave again. Sep out, leave again.

It's amazing how much dcm you can recover from those water layers. If you pour the 2 water washes togeter and you are patient, your yields will go up. I'm sure if you sep for 2 hours , you would still get some dcm, at least thats what happens when i use a 4L sep funnel.

How much PdCl2? Put more, I like 2.5 grams, gives higher yields, waste less safrole! Especially since PDCl2 prices have gone down last month

[DjTime]

Ok SWID did the benzo wacker in MeOH last night. Let reflux
8 hours double filtered out the solids. He is doing it in
two 2L sep funnels. He flooded both funnels with 10%HCL he
did 850 mL each funnel cuz it's half batches. He then extr-
acted with 250, 125, and 50 ml each funnel and combined ALL
the extractions in one funnel. And combine the aqueos layers
all in a 1 gallon jar and saved it. He then put his tone/dcm
solution in the freezer. A couple of highlights I will add
and if somebody could say yep or nope that's right. When I
hit the solutions with 10% HCL the top layer was bright orange and the bottom layer was redish-black (haven't done any thing else) Then I extracted with DCM and my tone/dcm layer was  dark dark redish orange. Does that color sound right? Im  getting ready to do the sodium bicarb, and NaCL washes right now, followed by the 5% NaOH. Any pointers for after I dry  my tone/dcm with MgS04, and start to distill my tone. About  how long does it take to do it right? And I'm looking for about 30-40 degrees above safrole temp right? Any help would be great. Thanks

 -peace

[Potential]

So I lost half of the potential 100+ ml of ketone in the washes?  Holy crap!  I will certainly pool the water washes next time...too eager, too many mistakes!

So if when I am distilling the ketone, am I right to believe that if there is very little safrole that comes over before the ketone, then the safrole to ketone conversion was good?  I'm just trying to identify where I came up short...

[technology]

Potential,

If you have very little safrole coming over, than most likley the conversion was sufficiant, how sufficant depends on the end product and whether amalgum is good, and this also depends on the purity of ketone.

DJTime,

Saturated NaCl 3 times, As you do these bicarb and salt water washes, you should be seeing the ketone/DCM solution getting progressively more greenish colored.
NaOH washs "3. If you did NaCL washs effectively you will have a very easy separation. You should see a very noticeable color change upon doing the first of these three washes wherein the ketone/DCM layer becomes a strange, thick reddish-brown with green overtones. This happens as the NaOH pulls the majority of the solvated hydroquinone into its layer, cleaning the ketone. The NaOH layer in the first wash will be very dark brown, almost black in fact. The next two will be a far lighter, watery, orangy color.


I hope that helps you..all the best

[DjTime]

Tech that's almost verbatum what MM says to do and
SWIM did it. But he was just suprised by the fact
that his shit looked and stayed redish brown, in
fact black "ALMOST" the whole time. Yes there was a
noticeable color change the first time SWIM hit it
with NaOH. And the water layers were infact as he
said orange. But here's what SWIM wants to know.
Say that you divided your batch in two, therefore
you would hit it with half the normal amount of
DCM, salt wash and NaOH and bicarb. But lets say
SWIM accidently hit the salt, bicarb and NaOH washes
with the full 500ml instead of the half (250).
Would that hurt the ketone, or just make it cleaner?
Thanks alot for any help.

 -peace

[nitrous351]

To answer someone's question about ketone distillation: Your ketone should come over about 25 deg C above your safrole, as long as all conditions are close to the same...remember though, you CAN'T distill ketone at atmospheric pressure. For best purity, distill once and collect the good fraction over ~10 degree range (you should have a forerun of 3 or 4 chems, so make sure you know how to stop and change a flask). Then, throw it all back into the flask and distill again, only this time narrow the range to ~2 or 3 degrees. Remember that pure ketone should have a very pale yellow color. Distillation time after doing a MM wacker is about 5-6 hours per distillation. DON'T rush it!
About the washes question: No, using too much wash won't hurt your goods, but you will be wasting chems. The reason we do many smaller washes instead of one big wash is because the smaller washes work more efficiently. See Zubrick's manual for a complete explanation.
Hope this helps   peace