09-20-03 02:47
No 460017
Oh fuck.. SWIM's eyes are killing him... He says he feels like he stuck his head in a vat of bleech! Here's the deal:
1. SWIM set out to wack
2. SWIM set a 2L-2N RBF in an oil bath (heat off, stirring full blast) with 2.5g PdCl2 & ~500ml MeOH. SWIM let the solution stirr for 3 hours - As per MM
3. When 3 hours were up, SWIM decided it was time to add the Benzoquinone (120g) + 50ml dH2O. How the fuck you disolve 120g of Benzo in 50ml of dH2O is entirely beyond me (and SWIM for that matter). As soon as SWIM popped open the jar containing the satchet of Benzo, SWIM was overcome with a burning sensation in SWIM's eyes, nose & throat! His eyes began tearing... oh fuck! this shit must be fucking toxic! Anyways, in order not to fuck everything up totally SWIM decided to grin & bare the irritation for a few moments longer while (seeing no other choice) he added more MeOH (solvent) to help disolve the Benzo/dH2O mix. SWIM ended up with a 3/4 full 2L-2N RBF with all this shit in it & the safrole addition still pending!
SWIM read writeups to wazooo on this, no fucking mention anywhere of the toxicity or precautions with regards to Benzo - SWIM would like to know if:
- He fucked up his reaction? (in which case, is there something to do to salvage it?)
- There are any precautions in coming steps SWIM should be aware of?
- (dead serious here) SWIM's seen pictures of reflux rxns where folsk put baloons on top of the reflux condenser (I imagine to block fumes like thes). SWIM don't got no baloons but he's got condoms, would that work just as well?
HELP!!!!
Peace y'all
Houston......................???????????
(Newbee)
09-20-03 02:59
No 460021
Just noticed after touching the Benzo (without fucking gloves like an idiot) got a bit of brownish yellow stains on my fingers.. wont' come out with soap/water...
Anything??
Houston...............????????????
(Hive Bee)
09-20-03 03:32
No 460029
It is recommended to handle benzoquinone in a fume hood. Benzoquinone is a very strong oxidizing agent that is why it burns. You can add it in the solid state to the flask using a funnel (it would be impossible to dissolve 120g in 50ml of water, and if the procedure wanted you to do that it would have explicitly instructed you to do so, which it did not). Obviously you have discovered that if you don't have a fume hood you want minimize the time you are dealing with this stuff so get it in the flask as fast as possible so you can still breathe. Your reaction is not botched, you can just proceed as normal, but you will want to remove some of the solvent (evaporate or distill) from your reaction flask to get it back down to a reasonable volume so that your safrole can fit in and still have headroom for stirring etc. You won't have to worry about fumes from the benzoquinone during the reaction, if its covered with liquid there won't be a problem. A condom/balloon is just a method for odor control (which there is no problem of odor with the benzo wacker) or a substitute for an inefficent condenser.
(Hive Bee)
09-20-03 03:35
No 460030
...2.5-grams.PdCl2 plus 500-mL.-MeOh. I don't know why you stirred for 3-hours. A catalyist and an alchahol don't do much. Apparently, you are dissolving 120-mL. of Benzoquinone
in a MeOh + dH2O solution + catalyst. I'm not sure about this,but you seem to have a a two-phase solution. I'm just guessing here.So, after you add the Meoh, the dH2O, and the PdCl2 and bring this solution up to reaction temperature you should add the benzoquinone to the solution dropwise.I assume that the Benzo and Meoh react, producing something. I don't know what. E-Mail me. I am curious.
callen + A.L.F.
(Newbee)
09-20-03 03:37
No 460031
Very much obliged for the helpful insight & advice. I'm going to set up for MeOH distillation to get rid of some of the solvent. and THANK G-D for NO MORE FUMES!!!
A few quick questions about MeOH distillation:
1. Vacuum or ATM? (what is the ATM bp of MeOH?)
2. Since I dumped in about twice as much MeOH as I should have (~600-700ml instead of the 400ml that was called for) I'm thinking of distilling out around 200-250ml, just want to confirm that's ok.
Let me know how SWIM should proceed & thanks!
Peace out -
Houston.................??????????
(Newbee)
09-20-03 03:44
No 460032
After distilling the excess solvent (MeOH) can it just be poured back into the bottle? I mean I would imagine it to be really pure after distillation, but wanted to ask just to be sure - I read somewhere something about MeOH/H2O forming an azeotrope, not sure what that is or how that would apply to my case - Insights?
thanks! - Peace out
Houston..................?
(Hive Bee)
09-20-03 04:40
No 460038
Atmospheric or vacuum, doesn't matter. With vacuum in general you won't recover much solvent unless you are using an ice bath on the receiving flask and ice cold condensing water and even then if your vacuum is too strong that will still be useless. And of course you don't want to distill solvents with an oil pump because it will contaminate your oil. But if you have an aspirator and don't care about recovering a few hundred ml's of MeOH it is faster.
Distilling back to the original target volume would be ideal. The distilled MeOH will not be super-pure and will have a significant amount of water in it. It is bad lab practice to pour reagents back into their bottles once they have been poured out, even if they were only poured into a (suspectedly) clean flask. Each time you do that you risk contaminating the entire bottle. Keep a seperate bottle of distilled wet MeOH that you can use for cleaning glass or whatever.
(Newbee)
09-20-03 05:18
No 460043
P has used benzo only once.Here's how P avoided agony:safety goggles, gloves,and a cheap respirator...close to a window with a fan .Measured the needed amount from the big container into a smaller container,fan not blowing.Once the lids were back on,the fan was turned on to blow any nasties out.Same deal when putting into the flask,no fan running when transferring-when done you want to blow the odoursout.
Honestly Neo,just to help you and not flame you-if you can't be bothered to spend $20 on safety stuff, maybe you should be doing something else.If you flicked some into your eyes,you would be blind.....
(Newbee)
09-20-03 05:51
No 460048
Yinga -
Read up on MeOH - Seems ATM bp = 65 C. Sure enough at around 68-70 C the stuff started coming over, but for some reason it's GREEN! I mean not lime green or anything, just semi-transparent with a clear green tinge. MeOH is supposed to be clear!?
There is of course the possiblity that the green stuff is some kind of forerun. I guess that remains to be seem. If it's forerun, the green tinge should get progressively lighter. (assuming the clear, pure MeOH follows)
Another thing: I'm wondering if the MeOH could have somehow combined with the Benzo? The sharp fumes from the Benzo appear to be stronger (or maybe i'm still sore from the earlier "encounter"). I'm thinking maybe they should have discipated by now even with the putsy lil exhaust fan I've got going.
Also, the MeOH appears to be coming over @ around 68C.
Let me know if you've got any thoughts.
PS: I've got goggles on, latex gloves, and full dress. Will most definetly invest in a respirator (and not gonna scrimp) - Any suggestions on model? filter type? (considering the type of rxns involved in this synth)
Peace
Houston............??????????
(Newbee)
09-20-03 06:48
No 460055
Gotta post a correction -
In my previous post i stated that the color of the MeOH coming over in the distillation was green. I guess it must've "looked" green cuz there was too little of it to see clearly. Now @ 300ml of distillate I can tell that it's much closer to Yellow
Still baffled as to why it's not clear & transparent. But figured I'd post the corrected observation.
Peace -
(Newbee)
09-20-03 18:31
No 460108
nice to hear you have some safety equipment.P got his respirator at a hardware store,it came with both paper and foam filters.P used both, and tied a damp cloth over the whole thing. Never got a single whiff of that foul stuff.P has no idea why your MeOH is green,possibly it's pulling some impurity out of the benzo??
(Hive Bee)
09-20-03 20:31
No 460117
SWIM thinks that you got some benzo pretty fast NEO.
He knows that when you have benzo on your skin and
it turns brown that it's good benzo. If it burns and chokes
you a little. You know you got good benzo. Make sure
you follow the writeups WORD-4-WORD your first few
synths. Those "dummie proof" writeups that MM has out
are that way for a reason. Once you do your synth the first
time step by step you see how things are going to react and
how they will look after you add product x to solution a.
I know it says that pre stirring your PdCL2 in MeOH will
increase yeilds, but if you would have seen that reaction
through like the MM's writeup said you'd know next time
how to do that whole benzo thing with out a hitch, and
you could have played with it a little like pre stirring. It does seem harmless but it's just one of those things The
same goes with the Al/Hg reduction. You have to follow
that by the book until you know what you are playing with.
I made the mistake of letting it get out of hand not once but twice and the secind time almost made me quit. It was that scarry, just because I thought the MeOH vapors in the room that came SPEWING from the top of my 800mm worth of
condensers was going to combust due to the fact that the
cold methyl gas was spraying all over a light buld. Not good man. But the tough part of the Wacker is getting your ketone I hope you have a good pump and good ventilation
(peanunt oil MAY smoke) Make sure to use insulation all
around the still head and NO cold water through your
condenser. Maybe just slightly luke warm. Be careful Neo
a dead or in jail be isn't worth all the honey in the world.
And don't rush it.
(Hive Bee)
09-20-03 22:07
No 460129
Benzo wont ever dissolve in 50 ml water, thats for sure. And its not what the write-up calls for. Everything mixed together. The benzo wont all dissolve believe me. Dont worry about it 450 ml solvent is plenty. Here what I would avise you to do:
Once you got the PdCl2, MeOH, water and benzo in your 2L flask, pre-stirred for a while, take you 2L flask and put it on your scale. Add the benzo directly to it until you've added the amount you want. Doing it this way has at least, IMHO, two advantages.
1. Less handling of p-benzo. You dont have to do 2 transfers.
2. Adding benzo top the solution will reduce the amount sent in the air. Less breathed as this stuff is really toxic.
Then proceed with the addition. I would advise using a little more catalyst. Prices have gone down on the international market lately(around 15% I think). Its worth it as to waste less safrole. I also find that a longer addition 1 and a half to 2 hours is preferable. I also like to keep the temp at 60-64.
And a final note: skip those NaCl washes, they really hurt your yield, as the keep a lot of dcm in. It can take a real long time to sep! I like 3X bicarb, 3X 5%NaOh, 2 water. Dry with epsom, distill.
(Newbee)
09-21-03 01:48
No 460159
Dj -
Thanks for lookin in :)
Aight.. so basically SWIM ran the reflux @ around 72 C on med. stirr overnight at around a drop or so every 2-3 seconds. SWIM noticed that #8 stirr setting seemed ideal (very light foaming in rxn flask). Lower then that and nothing happend, higher - and stirr seemed too strong (no foaming at all). SWIM saw why pre-stirring was important. This shit is really really hard to disolve and even after the 10 hour or so of total rxn time, there was still a tiny bit of shit left undissolved.
Anyhow.. SWIM is planning to invest in a respirator. The 3M-7000s model seems to provide excellent overall protection (http://www.websoft-solutions.net/Product
Quick questions:
1. I know I read somewhere that someone figured some washes could be skipped. I vaguely remember that it might've been talking about HCl washes. If that can be skipped I'd love to know about it!
2. Is HCl dangerous/hazardous? SWIM would be working with 31% HCl to make the working solution. Wondering (in advance this time) if there are any precautions or things SWIM should know about when working with HCl (or any of the other wash crap for that matter)
3. Last but not least, SWIM was wondering if anyone knows of a website or something where HOW TO DO WASHES is explained? I have zubrik's book. It's vague on this.. luv the jokes, but more matter-of-fact content would be nice.
that's it - Thanks for looking out for Neo!
Peace out Y'all -
(Newbee)
09-21-03 01:54
No 460161
Thanks Ocotea - I confused which washes to skip in my previous post. Thought it was the HCl. Still confused as hell as to how to do do the actual washes. Do i simply filter out my Benzo-wacker black shit then flood whats left with 1.7L of HCl soln? That would seem to give me a total of roughly 3L. I've got a 4L sep funnel.. Do I just let it sit till the "separation" happens by itself & then drain the bottom shit?
Help!! :)
Mwah - Peace Y'all
Houston...............???????????
(Hive Bee)
09-21-03 08:35
No 460195
SWIM thinks that if you look at ../rhodium and then
click on chemistry, go all the way down near the bottom of
the page until you get to multimedia. There are a few little
clips on how to do basic chemistry stuff. Organic Lab
Video Clips SWIM thinks. Watch them. It's really tight. A
4L sep funnel is awesome to have for the wacker, because
by the time you add your 1.7L of 10% HCL and the stuff
that is already in there you will have way more than 2L of
stuff and have only a 2L sep funnel to work with. For this
you can do two seperate runs in half of everything. Divide
the wacker in two equal parts. Pour one half in your sep
funnel Make your 1.7L of HCL put half of it in with the
one half of the wacker. Stir for a whole second. Then do all
washes and extractions in halfs too. Do 250,125,50 ml DCM
extractions. Do two, 250ml bicarb washes, SKIP NaCL wash.
Then do three 250ml NaOH washes. You should end up with
all the same amounts maybe just a bit more. Combine both
divisions at the end and add 50G of magnesium sulfate to dry.BUT if you have a 4L sep funnel disregard everything ust mentioned. Make sure to check out those clips on Rhodium's site, they are priceless for a beginner. Z's manual is kinda wishy washy for a newbee without any experience. Be careful.
-peace out
(Newbee)
09-21-03 09:09
No 460199
Sup Dj - Again, thanks for lookin in. I decided to start a new thread calling it "Post-Wacker for dummies" HELP! so that other newbees could benefit from the info. I figured it best belonged in a thread of it's own. Since you've 'heard' about this procedure recently - help/contributions would be greatly appreciated.
Again thanks bro - Peace.
Houston.................???????
(Hive Bee)
09-21-03 09:15
No 460201
Ocotea - The idea rocks, though frankly I haven't a blazen clue about how you propose to set a 2L-2N flask on a lab balance that max's out @ 1.2kg.
Thoughts?
Thanks - Peace.
09-21-03 09:31
(Rated as: insignificant)
(Hive Bee)
10-14-03 23:06
No 464618
DJTime: is that just your recommendation to skip the NaCl washes? Doesn't that wash have a purpose in the synth and wouldnt leaving something out be bad?
(Hive Bee)
10-14-03 23:45
No 464622
It's been stated a few times by others on the-hive that doing the NaCL washes causes an emulsion that is really shitty, actually it's not my mod at all. OcteaCybraum posted it and said it had no ill effect on his synth at all, in fact it helped his yeild. So I followed suit and it works much better that way. Your distilling your MDP2P in the end anyways so it won't hurt it in the respects of impurities if that is what you are asking. But I would not recomend that the NaCL wash be skipped during MM's Al/Hg reductive amination as it is used to pull out all the remaining HgCL2.
(Hive Bee)
10-15-03 18:21
No 464808
Sorry about that for some reason i thought you mentioned it first i shouldve addressed that to octea not you. Well then i guess ill skip the nacl wash during the wacker, but definately include it in the al/hg. Thanks