p2np->amphetamin with urushibara-dont work!!

brain · Linguist Extraordinaire

I tryed it several times, it just dont work !! Smile

-first makin p2np (using seweral methods, nitroethan+benzaldehyde+ [n-butylamine, cykloheksyloamine, NaOH etc.] on small scale [not more than 400g-total weight from synthesies]
condensation:

washing:

freezing:

drying:

than, makeing urushibara nickel:

(when reduced to Ni -washed etc.)

-reduced with it... +Al+HCl.. next basyfied,, no layers separated! ekstracted with toluene...

these shit just don't work Smile

will try Al-Hg/IAP maybe will be with better results? Wink

CherrieBaby · chouchou

Did you use the method in "amph.urushibara.html" at Rhodium's posted by Ritter? If so, I'll take Ritter's word before yours'. Please don't take that as an insult but he was/is a pretty systematic chemist.

Please post more details:
1) the specific Urishibara catalyst you used (there are well over 50 different ones described in Hata's book. (I'm guessing Nickel but did you use Zn or Al dust? What particle size was the metal dust? 200, 100, 50 mesh? Did you apply acid or basic washing?
2) the specific conditions that the reduction was done at, epecially details such as temperature, pressure, stirring, heating method, reductant.

"on small scale [not more than 400g-total weight from synthesies..." - I'd call that industrial scale!! Do it on a small scale next time and a) you won't feel so dissapointed, b) the reaction conditions will be easier to control. Ritter did it with "5g pure phenylnitropropene". You should've started by trying to duplicate what he did then scaling up if and when it worked.

brain · Linguist Extraordinaire

CherrieBaby · chouchou

OK, I was too hasty in my first reply to you. I read Ritter's prepn. and the most suspicious thing about it was the catalyst preparation. Urishibara catalyst preparation can be tricky (like all catalyst preparations). Aluminium grains (40-80 mesh) are normally used - not foil and the depostion of Nickel on Aluminium should be done at about 70-80 C.

I have copied the section from the book. This section is already in Rhodium's archive but is missing a very important summary table which I have included here:.

U-Ni-BA from New Hydrogenating Catalysts (Hata, 1971)

If you don't fancy using Al grains you can use Zinc (200 mesh) and the catalysts can also be made with Nickel, Cobalt, Copper or Iron. Nickel catalysts usually have the highest activity. Note that if your catalyst was grey rather than black or dark grey the activity may have been too low; that may explain why it didn't work. Apart from using foil instead of grains I also see that Ritter didn't wash the aluminium beforehand to remove oxide (with 6M HCl OR 3% NaOH soln., I think. The NaOH soln. looks like the best bet).

I'm not saying you can't use foil. I'm saying that it's tricky to get it right.

Can you get Aluminium powder/grains instead?

brain · Linguist Extraordinaire

starl1ght · Wed Mar 23, 2005 10:52 pm

this method is indeed difficult to get to work (ie. I have never succeeded). I was working with a different (legal) substrate, but it still didn't work when most other reductions have worked.

I think there are variables that have not been identified that if you just follow ritter's description cause the reaction to fail (not questioning his veracity, simply saying that the description is not foolproof).

DrugPhreak · Working Bee

This procedure does in fact work and posting pictures is really not the best way for someone to troubleshoot what went wrong here.

brain · Linguist Extraordinaire

i repeated it once more time... it worked-but yeld 30%-and thye product was yellowish-orange !! hard to puryfy Rolling Eyes

IndoleAmine · Dreamreader Deluxe

brain · Linguist Extraordinaire

eawen steam destilation didnt worked! the forduct have "bad" colour, and wird consistention, i didnt wont to fuck with taht and throw in trash...

IndoleAmine · Dreamreader Deluxe

Did you also try extracting the free base into dilute H2SO4/HCl, washing 4-5x with DCM/CHCl3, and then basifying with NaOH 20% again and extracting freebase with Et2O 4-5x?

Normally this removes all colored impurities (they are in the haloalkane washes) and is the standard method of cleaning liquid amines (provided that no heavy metals are present Wink

)...

Sounds like Urushibara would be a crap route though. Now what am I gonna do with that 5kg NiO I still have lying around? Make raney and construct a pressure hydrogenation bomb from a fire extinguisher? Very Happy

i_a

brain · Linguist Extraordinaire

yes

make "raney" add Al to NiO... and heat-will form Ni,, and rest of Al will melt with Ni... these Al-Ni is good for reductions Wink

just add it instead of Al/Ni (urushibara),,,, the Al will disolv and forming Ni will reduce??

IndoleAmine · Dreamreader Deluxe

not enough hydrogen from the Al/Ni alloy alone, you will have to introduce H2 into ther rxn by other means.

https://synthetikal.com/synthforum/viewtopic.php?t=375

(by the way raney nickel is not Al/Ni, you will have to dissolve away the Al to make finely divided Ni "sponge", and this is raney nickel - watch out, it can self-ignite if dry!)

i_a

brain · Linguist Extraordinaire

i know that Ni-Al isnt raney Wink

... but its too a good reducing material Wink

ranier w-2 formed in situ Smile

-why not?

in urushibara method must ad+ Ni,,, + Al+alcohol...+HCl

IndoleAmine · Dreamreader Deluxe

With urushibara, you will add more Al than Ni and you have to add HCl which will also dissolve the Ni slowly - and then you get maybe 30% yield... Wink

With raney + H2, you have 95% yield and can simply filter off the catalyst and strip off solvent (MeOH), then make the salt....

i_a