Scrotium
(Stranger)
01-24-02 23:43
No 260478
      NaBH4 red. of 1 kg ketone
(Rated as: excellent)
 Bookmark   

It was nothing special, really, just following LaBTop's procedure here: ../rhodium/chemistry /redamin.nabh4.txt.

750g store-bought MeAm.HCl (but it could have been made in one batch in a 5 liter RBF with AmmCl and formalin) were put into a container with a kilo of NaOH and shaken up some. A small cup of water was carefully placed in it and the lid with a hose with an inline valve was screwed on. The hose was attached to some coils of metal tubing submerged in a dry ice/acetone bath, and the other end of the tubing led to a flask also submerged in the bath. The gas generator was shaken up and the gaseous MeAm condensed into the flask with manipulation of the inline valve to prevent excess gas not being condensed, and also to prevent suckback between shakings of the generator.

When gas generation had mostly died down, the valve was shut and the receiving flask, which had been preweighed, was weighed again and showed about 305 g of MeAm had been condensed. 3 liters of MeOH was cooled in the dry ice/acetone bath, and the liquid MeAm was added to it. This was poured into a 20 liter flask (sorry, the 10 liter comment yesterday was a mistake. Swim was going to use a 10 liter jar but was having trouble getting a stirbar to spin on the slightly convex bottom. But 10 liters would be more than enough room.) situated in an ice bath on top of a magnetic stirrer, and 1000 beautiful grams of MDP-2-P was added. Approximately 300-400 g silica gel was added and it was stirred with a 2.5 inch egg shaped magnetic stirbar for 30 minutes.

The now orangeish solution was decanted away from the silica gel into a clean flask and the silica gel was rinsed with a small portion of methanol which was added to the other flask. The silical gel was removed from the 20 l flask and the methanol/imine was added back into it with the stirbar. The flask was placed back in the ice bath on the magnetic stirrer.

Stirring was started, and 100 grams of NaBH4 was added a spoonful at a time over the course of maybe 3 or 4 hours, making sure that the fizzing had died down and the temperature was below 15C before each addition. After addition was complete, the mixture was allowed to stir for about 20 hrs.

The next day, most of the rxn mixture was poured into a 5 liter RBF equipped for distillation, and methanol was distilled off for awhile. When there was room, the rest of the rxn mixture was poured in and all of the methanol was distilled off. 3 liters of water was added to 1 liter of 31% HCl. This was poured into the 5 l flask and all of the residue dissolved. This was poured into a 10 liter jar and washed 2x with 1 liter of toluene. This was done by adding the toluene to the jar, shaking, letting the phases separate, pouring off as much toluene as possible, then pouring some of the mix into a 4 liter sep. funnel and separating, then pouring the rest into the sep. funnel and separating.

The aqueous solution was then basified with a sat. solution of NaOH to pH 14 and a golden brown oil separated out and fell to the bottom. The aqueous solution was poured away from the oil and the oil was poured into a beaker. There was still quite a bit of oil in the aqueous solution stuck to the sides of the glass, floating as beads, and such. DCM extraction was attempted but a big emulsion resulted so the whole thing was vacuum filtered through celite on a large buchner funnel. Some DCM was sucked into the pump, but oh well. The phases separated nicely after filtration and 3 extractions were done with 1 liter DCM each.

The DCM and oil were combined and washed twice with water and once with brine (1 liter each) using the technique of shaking in the 10 liter jar and separating in fractions in the 4 liter sep. funnel. The DCM was dried with MgSO4 (baked epsom salt), placed in a 5 l RBF, and the DCM was distilled off without vacuum to leave what looked like 750-800 ml of golded brown freebase oil. This was added to a 1 liter RBF situated in a heating mantle on top of a magnetic stirrer. The flask was equipped for distillation with a claised adaptor and a fractionating column (about 30 cm) packed with stainless steel wool obtained from a Chore BoyTM scrub pad. Fast stirring was started, and heat and vacuum was applied. The vacuum quickly sucked the rest of the DCM into itself, so the heat was turned off while the pump oil was changed. Heat and vacuum was once again applied, and after awhile the temp quickly rose to 111C (Swim isn't positive about this value, it's been awhile and he can't remember for sure but thinks this is what it was) with very few drops coming over before reaching this temp. The vacuum strength isn't known exactly, but is suspected to be somewhere around .4 mmHg because it pulls MDP-2-P over at a solid 100C. Distillation continued at a rate of probably 2-3 drops per second for quite awhile and the temperature gradually dropped to 110C due to the vacuum gradually increasing. Finally distillation slowed greatly and the temp started rising, so distillation was stopped. The preweighed receiving flask was weighed and the weight of water-white MDMA oil was 745 g.

This oil was added to 3 liters of ice cold anhydrous acetone and gassed with HCl and filtered repeatedly until no more precipitate formed. The crystals were washed with a small amount of acetone which was added to the gassed acetone and placed in the freezer. The crystals in the buchner funnel were dried by sucking air through them for awhile then by placing the whole mass on a piece of glass with a space heater blowing on it. Final weight was 793 grams of sparkly white MDMA.HCl. The next day there was quite a bit of precipitate in the acetone in the freezer. This was filtered, and cleaned up and the acetone was rotovapped down to about 600 ml and placed back in the freezer. More crystals precipitated.

After quite a bit of work to retrieve every last bit, Swim was left with 866 grams of clean, sparkly white MDMA.HCl.
 
 
 
 
    Osmium
(Stoni's sexual toy)
01-24-02 23:53
No 260486
      Re: NaBH4 red. of 1 kg ketone  Bookmark   

Sniffle. blush

Sorry bees, but exciting and romantic stories with a happy end always make me weepy.
[wiping off tears]
 
 
 
 
    LaBTop
(Daddy)
01-25-02 14:56
No 260751
      Re: NaBH4 red. of 1 kg ketone  Bookmark   

I like the way you solved the problem of the homemade 10% methylamine in methanol solution.

You could have saved yourself a LOT of work by just following my instructions and adding 8x the ketone volume as water (tapwater will do, 8 liter in this example) in a bucket with a bottom valve, instead of evapping off the methanol. Imagin you have to evap off 30 kg MeOH when you step up to 10 kg ketone.
It's not necessairy.
Then tapping off the raw freebase, which is a MUCH smaller volume, and distilling this to pure freebase is just as good as any A/B wash. And you win a LOT of time, and save yourself a lot of work.

And use acetone, 8x the volume of pure distilled freebase for HCl-gassing. It will give you nearly 98% of your crystals in one go. Saves a lot of time also. Just set the 8x volume acetone aside for the next batch, no need to distill or whatever else. Use it again for the next batch.

And if still in doubt of the purity of your first crystals, just recrystallize in just enough boiling ethanol to dissolve all your crystals, then add icecold acetone, 3x the volume of ethanol, put in freezer, wait 3 hours or a night, and pour off any liquid containing any impurities.
Wash with acetone and dry your recrystallized crystalls again, voila, 98-99% purity.

Recrystallisation rules:
Recrystallization is used to purify solids. The solid is dissolved in a minimal amount of boiling solvent and then cooled to form crystals without impurities. When picking an appropriate solvent for a recrystallization use the following general rules:

--The best solvent for recrystallization is one in which the solid is only slightly soluble at room temperature, but is very soluble when heated.
--The impurities should be soluble in the solvent at room temperature to prevent them from crystallizing out with the product.
--The solvent should have a low boiling point so that the crystals can be taken out of solution and dried as soon as possible.
--The solvent should not react with the solid.
LT/

WISDOMwillWIN
 
 
 
 
    terbium
(Old P2P Cook)
01-25-02 18:33
No 260773
      Re: NaBH4 red. of 1 kg ketone  Bookmark   

You could have saved yourself a LOT of work by just following my instructions and adding 8x the ketone volume as water (tapwater will do, 8 liter in this example) in a bucket with a bottom valve, instead of evapping off the methanol. Imagin you have to evap off 30 kg MeOH when you step up to 10 kg ketone.

Well, I was going to let the procedure stand without comment but since you mention it ...

As opposed to dumping in 80 liter of water and then having to manipulate over 100 liters of liquid? Distilling off 30 kg of methanol, in the process of making 8 kg of MDMA, is not that difficult; it could be quickly done in a 22L flask or, even better, a large rotavap.

What I would have done to streamline the procedure would have been to not bother using the silica gel.
 
 
 
 
    LaBTop
(Daddy)
01-26-02 01:12
No 260883
      Re: NaBH4 red. of 1 kg ketone  Bookmark   

Terbium, let's have a closer look at Scrotium's fluids tongue, needed to process 1 kg of ketone, between "" The next day"" and ""to leave what looked like 750-800 ml of golded brown freebase oil"" :
3 liter H2O
1 liter 31% HCl
2 liter toluene
1/2 liter saturated NaOH
3 liter DCM
2 liter H2O
1 liter brine
-------------
12.5 liter fluids in total, which include 31% HCl, toluene, concentrated NaOH, DCM, concentrated NaCL.
Things you not easily would want to throw in the environment, or worse, in your groundwater.
If you are the right researcher, you try to recycle as much of these fluids as you can, AGAIN a LOT of even more extra work involved. WORK = time = RISK, remember that.


Now instead of this, I keep saying to add JUST 8 liter WATER.
Wait until all raw freebase has settled at the bottom, and tap it off, directly vacuumdistill it.

Btw, this 8 liter water/2 liter MeOH+some leftovers, you don't need to throw away, store it for the next batch, and use it again then.
NO WASTE fluids AT ALL. No EXTRA WORK.
Only the last time when you think you have made enough for your retirement, then you throw it away in a car repair shop depot for hasardous fluids, together with all the concrete-hard leftover tars you have decanted in one metal bucket, everytime after you distilled your raw freebase and they were still snothot, darkbrown fluids.

Tell me please, what amount of waste fluids and LOTS of extra work and risk you prefer.
I throw in water, separate, and distill. Seems to me like quite a fluently fast process.

I agree, silicagel is not really needed when doing a Methylamine/NaBH4 batch.
And again, most of you seem to have lost their heart to those crappy milky white silicagel beads.
I told you many times, it must be Merck silicagel, 3-5 mm, amber coloured. Or 3A molsieves. NOT 4A or 5A. Only 3A molecular sieves take up water from alcohols. LT/

WISDOMwillWIN
 
 
 
 
    LaBTop
(Daddy)
01-26-02 01:35
No 260894
      Re: NaBH4 red. of 1 kg ketone  Bookmark   

Terbium, while we are on the subject of nitpicking tongue, would you be so kind and show me ONE publication of Morris Freifelder, the most respected author on reduction in America, where he used sodium borohydride to reduce imines to amines ?
As you may remember, you used his name a few times as a reference in a discussion. LT/

WISDOMwillWIN
 
 
 
 
    terbium
(Old P2P Cook)
01-26-02 04:25
No 260961
      Re: NaBH4 red. of 1 kg ketone  Bookmark   

would you be so kind and show me ONE publication of Morris Freifelder, the most respected author on reduction in America, where he used sodium borohydride to reduce imines to amines ?
I am not aware of any. I have a book by Freifelder on catalytic hydrogenation and have made reference to that and to papers of his referenced therein but I do not know of any work that he did with NaBH4. IIRC, it was H.C. Brown who pioneered the field of hydride reducing agents in organic synthesis.
 
 
 
 
    LaBTop
(Daddy)
01-26-02 07:14
No 261014
      Re: NaBH4 red. of 1 kg ketone  Bookmark   

Yep, good old Herbie.
According to Brown's "HydroBoration" diglyme is the only common solvent in which sodium borohydride is very soluble (he states btw that Alfred Stock is the "father" of organoborane chemistry, publishing an explosive reaction with acetylene in Ber 56, 789 {1923}).
Brown and Schlesinger at Purdue first synthesized sodium borohydride in 1942-3, and a few years later chemists from the same department synthesized LAH. The research on sodium borohydride was classified, because of the war, thus LAH became the preferred reducing agent for organic chemistry.
H.Brown's book "Hydroboration" on using sodium borohydride in synthesis doesn't cover borohydride reductive amination (since I invented that particular use ), there still is a lot of information in the 289 pages that may be helpful, if you haven't already seen it. He supervised the team at Purdue that invented sodium borohydride and developed it as a reagent. Most of their work was classified for a long time because it started during WWII.  LT/

WISDOMwillWIN