Sciencemadness Discussion Board

Exact conditionf for preparation of Urushibara nickel

goldberg - 21-1-2020 at 10:32

I did not found such thread if i missed such information somewhere sorry for that.
I have read both original papers by Urushibara and monography about this catalyst by Hata.
Procedure for deposition of nickel on zinc to make Urushibara catalyst precursor calls for
mixing 3ml of water with 10g of zinc powder and then adding 10ml solution containing 4.04g NiCl2 * 6H2O (that corresponds to 1g of metallic nickel) on boiling water bath with string.

One thing seems strange to me: 3ml of water and 10g of zinc powder whatever particle size is it has no chance to be a suspension of zinc in water. Zinc powder will absorb water.
This procedure is cited on and on and i double checked that i read this correctly.
More over after deposition mixture is filtered on sintered glass funnel so it has to contain significant amount of liquid. Moreover in general description i read that one should add solution of nickel chloride to suspension of zinc in water.

I would be very grateful for clarification of this. Amount of water is just too low. What is correct amount? About 8 to 9ml of water will form suspension when mixed with 10g of 80um zinc powder.

Also how long this reaction between zinc and nickel chloride should go?
I read "reaction will soon subside" But soon is 5 seconds or 5 minutes? I should stop it when it will subside but gas will be still evolving or should i wait until it will completely stop?

Also i did not found any mention about particle size of zinc powder.

I read that somebody here carried out a few experiments with this catalysts and i would be very grateful for any clarification of this. Also any information (or photos) what i should observe (or not observe) during this reaction will be very helpful.

Also how sensitive to air is U-Ni-B? Can i just pour it from beaker after activation to reaction vessel exposing it to air for a few seconds or should i protect it from ANY contact with air?

I would like to just to try to reproduce this experiment just for fun and try to reduce some acetone to isopropanol under atmospheric pressure to check it's activity.

DavidJR - 21-1-2020 at 11:27

Maybe it's meant to be a paste rather than a suspension. I'm not sure.

Chemplayer did it by tossing nickel chloride solution onto dry zinc dust: https://www.bitchute.com/video/PTSXPBiJvzre/

karlos³ - 21-1-2020 at 12:30

If you want to use it for the reduction, why not use the french pseudo-urushibara, invented many years before Urushibara himself invented these catalysts?
It is essentially the same, U-Ni-NH3, here is a link: https://www.sciencemadness.org/talk/viewthread.php?tid=20153

I used that method for the amination of ketones, for the reduction of aldehydes, the reduction of oximes and the reduction of an oximinoketone to an aminoalcohol with huge success.
And you don't even need to form the catalyst separately, it works in-situ.

goldberg - 21-1-2020 at 23:09

@DavidJR: I have seen this video. This procedure is different than original preparation of Urushibara nickel. Lack of stirring, carrying out reaction at room temperature and lack of showing that prepared catalyst actually exhibits any activity. For this reasons i do not count this video as source of information.

@karlos³: Thanks for information. I never heard before about this method. Looks very interesting. Are there any references in scientific publication or only this patent?
I'm happy to read that people from this forum were able to reproduce this but i'm also curious if someone investigated this reaction in greater detail.

Could You please write two phrases more about conditions that You have used during this reactions?
What should be granulation of zinc powder? Or it is not very important?
Intuition tells me that the finer the better. For example 100um zinc powder will be good enough?

morganbw - 22-1-2020 at 12:08

for the zinc/nickel coupling there is some information/not huge on the hive archives. There is also some information on the vespiary again not huge.
Even though the info of real life use is not huge it is there. Unfortunately mostly not in the forms of scientific papers.
There is enough info for a guideline on how to use. Ignore if you choose, but I feel that the zinc/nickel coupling was/is a gift to an amateur chemist.

karlos³ - 22-1-2020 at 12:13

It is(a gift for amateur chemist, I mean)!
Just check the zink-nickel thread on there.
I use zinc powder that is sold for fireworks, don't know how fine it is, just the usual stuff.
I use the conditions that were used by Scr0t in the thread on here, in his second experiment.
I achieved 84% yield for the direct amination of phenyl-2-propanone, there is nothing out there thats beat this outcome.
Even phenylacetoxime yielded less product with this reduction.
If you ever want to aminate a ketone to its primary amine, this reaction is your best choice, I really love it.

[Edited on 22-1-2020 by karlos³]

Abromination - 22-1-2020 at 16:01

Quote: Originally posted by goldberg  
@DavidJR: I have seen this video. This procedure is different than original preparation of Urushibara nickel. Lack of stirring, carrying out reaction at room temperature and lack of showing that prepared catalyst actually exhibits any activity. For this reasons i do not count this video as source of information.

@karlos³: Thanks for information. I never heard before about this method. Looks very interesting. Are there any references in scientific publication or only this patent?
I'm happy to read that people from this forum were able to reproduce this but i'm also curious if someone investigated this reaction in greater detail.

Could You please write two phrases more about conditions that You have used during this reactions?
What should be granulation of zinc powder? Or it is not very important?
Intuition tells me that the finer the better. For example 100um zinc powder will be good enough?

I suppose I understand your reasoning in a lack of belief, but chemplayer has proved otherwise to be a very accurate and valuable source to many of us.

karlos³ - 23-1-2020 at 04:06

chemplayer has also attempted the nickel-zinc amination after I suggested that to him: https://twitter.com/ChemPlayer1/status/1124537533394591745
I don't know how it turned out though.

goldberg - 23-1-2020 at 08:07

@karlos³ could You please give me more details about conditions of Your reaction?
especially what was ratio of zinc powder to water. You dissolved 4.04g of NiCl2 * 6H20 in 10ml water or what concentartion you have used? Did You carried out deposition on boiling water bath or room temperature?
Or You just prepared everything in situ like in mentioned patent?

And did You managed to reduce functional groups that are more resistant than imine or oxime?

@Abromination: I'm just very careful when someone does not tells much about his results like in this video about Urushibara nickel from chemplayer on youtube.

I'm thinking about good substrate to test. Ideally something that is solid so i could easy do TLC. Sorbic acid? can be cheaply purchased as preservative and has double bond to hydrogenate. Camphor? Or maybe something like menthol or limonene that i will be able to check by smell?

Also i came across a few papers about deoxygenation of benzyl alcohol and it's deviratives using raney nickel and isopropanol or mixture of ethanol and water. Does anybody tried this with Urushibara nickel and/or Ni/Zn couple?

Also there is also U-Ni-N activated by just refluxing Ni/Zn in isopropanol. It seems to be even more obscure than U-Ni-A and U-Ni-B. Does anybody tried to use it?

I'm thinking about good way to examine activity of prepared catalyst. Measurement of absorbed hydrogen will require a little tricky setup especially to get reasonable precision of measurement..
It would be also interesting to examine mechanism of this reduction i'm open to any suggestions how to do it.

karlos³ - 23-1-2020 at 09:27

I just ran it like in the patent, with the improvements Scr0t mentioned here: http://www.sciencemadness.org/talk/viewthread.php?tid=20153&...

I only reduced an aldehyde to its alcohol, oximinoketones to aminoalcohols, reductively aminated ketones, and reduced oximes to amines.

But the system also reduces double bonds in unsaturated acids, nitriles to amines, and aromatic nitro groups to amines, see here: https://erowid.org/archive/rhodium/chemistry/zn-ni.couple.ht...
However, I haven't tried that, it wasn't interesting to me.
Here is another successful experiment from someone else: https://chemistry.mdma.ch/hiveboard/novel/000470154.html

It is the best system to make primary amines directly from ketones.

If you want to see that in more detail, see the zinc-nickel thread at the vespiary, I have posted all my experiments on there.
I can't access that right now, the site is offline, otherwise I would have posted one of the writeups here.
I dissolve nickel acetate directly in the ammonia solution, add ethanol as cosolvent and the substrate, let it stand a few hours(in case of direct aminations), and then add three portions of the zinc powder five min apart from each other, with gentle heat in the water bath at the end.
Otherwise you would boil off the ammonia.

[Edited on 23-1-2020 by karlos³]

[Edited on 23-1-2020 by karlos³]

Corrosive Joeseph - 23-1-2020 at 09:36

Quote: Originally posted by karlos³  

I only reduced an aldehyde to its alcohol, oximinoketones to aminoalcohols, reductively aminated ketones, and reduced oximes to ketones.


Momentary lapse of reason on the last one there..... You reduced oxime to amine.

;)


/CJ

karlos³ - 23-1-2020 at 09:57

Oops :o
Corrected it.

goldberg - 24-1-2020 at 00:34

How about reduction in basic condition using NiCl2/Zn? Nickel will form hydroxide. I read that reduction of ketones and aldehydes is favored by basic conditions.

Urushibara has found that nickel on zinc without activation does not exhibit catalytic activity.
So if i'm correctly reasoning hydrogen evolved during precipitation of nickel is used for hydrogenation before insoluble zinc compounds will clog up catalyst?

Has anybody tried to use external hydrogen source? This route seems very good unless there will be need to acidify post reaction mixture due to precipitation of zinc hydroxide which will be messy.

Thanks a LOT for information on this but i'm still curious about first precipitation of nickel on zinc and using it as catalyst in separate step.
One pot procedure seems great but it can require quite a bit of zinc powder.
The other problem is that not everything is soluble/misticible with water...

Do You know anything about how pure this zinc has to be? I read that lead is poison for raney nickel. I found one place with zinc powder but it is contaminated with about 0.1% of lead...

How about making suspension of Urushibara nickel with diluted (say 1%) NaOH or acetic acid, adding compound for hydrogenation and then inserting cathode (nickel?) electrolytic key (say agar + KCl) and in another beaker anode?
I have found a few papers about raney nickel cathodes and even reduction of pyridine ring in nicotine has been done in quite good yield.

All papers about Urushibara nickel tells for 3ml of water for 10g of zinc (i have checked this again, even paper about study of structure of Urushibara nickel tells this procedure).
This does not seems like an error. Zinc powder in Japan in 1950s was rather ordinary zinc powder. Is this wrong on purpose?
I have noticed that if there will be 8ml of water of 10g of zinc (this is actually a suspension of zinc in water, not water absorbed on zinc as with 3ml of water) reaction is more vigorous.
I read in Hata monography than the more vigorous reaction the better.

Also does anybody had success with cold prepared Urushibara nickel?

Another thought: how about using colloidal zinc instead of powder? Filtration of used up catalyst will be impossible, the only way will be extraction of product. But beside that there could be chance for huge surface area right? Unfortunately i did not managed to found any information about preparation of colloidal zinc.

stoichiometric_steve - 24-1-2020 at 01:01

Quote: Originally posted by karlos³  

the system also reduces double bonds in unsaturated acids, nitriles to amines, and aromatic nitro groups to amines


Excuse my ignorance, but do you know if this has been tried on nitroalkenes?

karlos³ - 24-1-2020 at 04:30

Quote: Originally posted by stoichiometric_steve  
Quote: Originally posted by karlos³  

the system also reduces double bonds in unsaturated acids, nitriles to amines, and aromatic nitro groups to amines


Excuse my ignorance, but do you know if this has been tried on nitroalkenes?

It has been tried on nitroalkenes, it did not work.
However, it works with the "real" urushibara made from nickel and zinc and digested with formic acid, just not in great yields, as a friend has tried that.

It is to me of great interest to try it on nitroalkanes sometimes, I am sure it will work very well on them.

Corrosive Joeseph - 24-1-2020 at 05:38

Please don't write if off just yet...... There was one attempt on nitroalkenes by somebody who had never done the Zn-Ni-NH3 procedure before, it was not carried out to the letter and no characterization was done.


/CJ

karlos³ - 25-1-2020 at 12:44

No, I wrote that off.
He is a good chemist, and that he got absolutely nothing out of it convinces me, that the basic Ni-Zn does not work on nitroalkenes.
However, there is still the acidic urushibara for that, so it does not really matter.

goldberg - 26-1-2020 at 23:13

@karlos³: could You please write here more details about this experiment? Like exact amount of reagents, temperature time and method of isolation and analysis of products?

Ad reductive amination: is it possible to prepare secondary or trietriary amines with NiCl2 + amine + Zn?
And how about using Urushibara cobalt? Anybody ever tried this catalyst? Cobalt exhibits lower catalytic activity so in this case there would be possibility to get better selectivity because imines are easier to reduce than aldehydes and ketones.

karlos³ - 27-1-2020 at 13:55

Look, heres my reduction of an oximinoketone to aminoalcohol EXACTLY like in the patent(have you read it, it is a good read?).

First, made solution 1, and dissolved
-2g/8mmol Nickel acetate
in
-10ml Water

Solution 2 was made from ~5ml EtOH and
-3,8g Isonitrosopropiophenone(23,3mmol), added
-55ml NH3 20%(308mmol) and then
-1g KOH in 2ml H2O

to solution 1 then
-6g Zn(92mmol)
were added, and around 15 minutes later, solution 2 was added in portions but over around 25min instead of the 2-3 hours in the patent(but compared, they used 3l solution with 200g nitroketone in there).
It has not warmed up that much, so a bit heat in the waterbath was added to reach 60°C for 20mins.
Then left stirring for a 6h more.
The precipitate was vacuum filtered and and is washed with 3x15ml dH2O
It was then based with some sodium carbonate and the base extracted using 3x50ml toluene, from which after washing and drying, the oxalate salt was precipitated.
Drying of that afforded 4,2g(17,7mmol, 76%!), some of this was dissolved in H2O, based and re-extracted with DCM and the HCl the salt formed, which had a mp of 190-192°C(i.e. it indicates this is the dl-norephedrine).


You really should just read the patent man.

[Edited on 27-1-2020 by karlos³]

goldberg - 28-1-2020 at 01:56

@karlos³: unfortunately this patent is in french and i do not speak french. Second recreation of patent is not always an obvious thing.
So i this case nickel ions became complexed by ammonia and thats why nickel does not precipitate as hydroxide?
Does this procedure works for synthesis of secondary and trietriary amines?
Ni2+ does not have to form complex with more complicated amines.

Tsjerk - 28-1-2020 at 02:06

Quote: Originally posted by goldberg  
@karlos³: unfortunately this patent is in french and i do not speak french. Second recreation of patent is not always an obvious thing.
So i this case nickel ions became complexed by ammonia and thats why nickel does not precipitate as hydroxide?
Does this procedure works for synthesis of secondary and trietriary amines?
Ni2+ does not have to form complex with more complicated amines.


Nickel can't precipitate as the hydroxide if it is not oxidized...

https://translate.google.com

Edit: zinc is kept in solution by the ammonia though.

[Edited on 28-1-2020 by Tsjerk]