Aurelius (Hive Addict)
05-09-03 05:29
No 432241
      Replacement of the Hg/Al amalgam reductions?     

In a time long, long ago, Piglet posted on 2/2/99 that P2P could be reductively aminated with Ni(NO3)2, Zn and NaOH to yield Amphetamine.  Does anybody have a reference for this (particular) reaction?  (Zinc/Nickel couple)
(Chief Bee)
05-11-03 21:08
No 432666
      Very similar to Urushibara-Ni     

Post 270027 (Rhodium: "Zn/NiCl2 reduction of oxime/nitro/nitriles/ketone", Chemistry Discourse)

../rhodium/chemistry /urushibara.html

And here we have a few articles on the subject, courtesy of Lugh: ../rhodium/djvu /znnicouple.djvu
(Djvu reader plugin at )
(Hive Addict)
05-13-03 23:43
No 433004

How did I manage to miss such a wonderful thread!!  that stuff is as versatile as it comes.  Thanks Rhodium.
(Hive Bee)
05-26-03 16:33
No 435620
      Reduction of phenylacetonitriles w/ Zn/Ni couple
(Rated as: excellent)

This patent might need a Oh and Lili, I found a bug in the patent tag too!laugh

Reduction or hydrogenation by the use of a zinc-nickel couple.
Patent FR56321 CA 52:61361


The Zn-Ni couple is prepd. by dissolving 7 parts NiSO4 in H2O 70 parts, adding Zn powder 70 parts, and stirring for 15 min. Dehalogenation and reduction processes are claimed.  2-Bromo-4,5-diethoxyphenylacetic acid 50 parts dissolved in 50% KOH 200 parts and H2O 400 parts is added to the Zn-Ni couple while the temp. is maintained at 50-60C, and the mixt. is kept 48 hr. with stirring. Filtration, acidification, and purification gives 80% 4,5-diethoxyphenylacetic acid, mp. 81-82C.  A suspension of 2-bromo-4,5-diethoxyphenylacetonitrile 10 parts in alcohol 4, H2O 60, and 50% KOH 20 parts is added with stirring to a Zn-Ni couple prepd. from Zn powder 120 parts and NiSO4 6 parts while the temp. is maintained at 50C.  Two more identical portions of the suspension are added at 15-min. intervals. After 6 hrs. at 55C, the mixt. is filtered, the alcohol distd., and the amine, purified by formation of the sulfate, obtained in 70-72% yield, bp15 160C.

fear fear hate hate
(Hive Addict)
05-26-03 18:18
No 435638
      FR 56321     

There isn't a bug in the patent tag. You must put a space between the FR...US...etc...and the numbers.
Patent FR56321
Poly Voo Francias???laugh
Peace of the reaction


Empty the prisons: make room for Congress!
(Hive Bee)
05-26-03 23:59
No 435708
      Corrected... First I teach you, now you teach...     

Corrected... First I teach you, now you teach me.laugh

fear fear hate hate
(Hive Bee)
05-28-03 05:10
No 435995
      Patent FR971429
(Rated as: excellent)

This comes from patentPatent FR971429. The
patent FR56321 was an addition to this one.

Exemple 1 Transformation of ketones to their corresponding amines

The present invention allow us to obtain amines by reduction of ketones in the presence of excess ammonia.
Starting with cyclohexanone we obtain cyclohexylamine in the following manner:

5 parts nickel sulphate is dissolved cold in 80 parts NH3 20%. Fifteen parts cyclohexanone are added, stirred and the dissolution is helped by adding 20 parts 95% ethanol. The addition of 10 part of Zn powder signals the start of the reaction. Two more 10 parts of Zn powder are added  successively. After a few hours, the solution is centrifuged and by proper treatment, we recover 70-72% cyclohexylamine.
In the same manner we obtain isopropylamine from acetone, isobutylamine from methylethylketone, etc.

Exemple 2  Transformations of nitrocetones into their corresponding aminoalcools

Solution 1
Nickel sulphate 80 parts
Water 600 parts

Solution 2
Isonitrosoacetophenone 200 part
Regular NH3                 2670 parts
KOH 35%                      120 parts

Shake solution 1 then add in one shot, 600 parts Zinc powder. 15 to 30 minutes later, start adding solution 2 keeping the temperature below 60-70 celsius. The addition should take 2-3 hours. The solution is left stirring for a few more hours. The solution is centrifuged to separate the zinc precipitate. The precipitate is washed several times with 250 parts distilled water. The washes are added to the solution separated by centrifugation as above. Potassium carbonate is added in sufficient quantity to extract the base just formed. After washing the extracted base, it can be reacted with sulphuric acid in the usual conditions to yield the sulphate salt. The yield starting with 200 parts of nitroketones is around 90% of theoric following the reaction
C6H5COCNOH-CH2     + 6H+   =    C6H5COHCNH2CH2

Exemple 4 Transformation of oximes into primary amines

It is quite normal that oximes give their corresponding amines since nitro containing molecules are regularly transformed into amines. This way we obtain B-phenylethylamine from the oxime of acetophenone. The oximes of phenylacetone and benzylacetone give respectively with yields of 85-88%, the phenylisopropylamine and benzylisopropylamine.

Example 6 Reduction of a nitrile function to its primary amine

Diverse nitriles are reduced to their corresponding amine by the zinc/nickel couple by the addition of 4 hydrogen atoms. This way, benzyl cyanide gives phenyl ethylamine


The present invention has for goals:

1. A reduction or hydrogenation of organic compounds in aqueous or hydroalcoolic solvent, thas consists essentially in doing the reaction with the metallic couple Zinc/Nickel
2. An execution mode for this invention, that consists in preparing the Zinc-Nickel couple using nickel sulphate at a maximum concentration of 5% of the hydrated salt and of metallic zinc, and to effectuate the reduction at temperatures under around 50 Celsius
3. Application range from transformation of ketones in amines, nitroketones in aminoalcools, of ethylenic derivatives into saturated compounds, oximes into primary amines, of carboxylated aldehyde or ketone into alcool, and of nitriles into primary amines.

I translated the important parts. If anybody feel that some parts may be missing in the above translation, its just that they dont give more details. Remember this patent was applied for in the 1940's so a lot must have been learned about this system since then.
(Hive Addict)
05-29-03 09:55
No 436270

Has anybody thought to use cinnamaldehyde in the Zn/Ni couple?  It reduces both C=C and aldehyde functionalities.  The product would (presumably) be 3-phenylpropanol, just a step or three away from P2P.  All OTC.
(Hive Bee)
05-29-03 16:11
No 436334
      My experience being limited     

I was curious how you would transform the alcool function(on carbon 3) to the ketone(on carbon 2)?
Any ideas?
(Hive Addict)
05-29-03 22:09
No 436400
      Read more     

Go to Rhodium's site.  You'll find an article on dehydration of alcohols with KHSO4 to give the alkene. The alkene formed is allylbenzene.  This can be isomerized just like safrole.  The product formed in propenylbenzene.  This can be oxidized in several ways (performic acid) to P2P.
05-30-03 04:04
No 436437
      Perhaps KHSO4 can be replaced with NaHSO4.     

Perhaps KHSO4 can be replaced with NaHSO4. The NaHSO4 is a very common OTC item.
(Hive Bee)
05-30-03 04:36
No 436445
      Its a primary carbon     

The mecanisms has to go through a carbocation which you wont get for this particular compound. Primary carbocations are highly unstable and almost dont exist. I highly doubt this would work. What do you think?
(Hive Addict)
05-30-03 05:27
No 436456
      Primary Carbon     

Which reaction are you referring to?  The reduction or the dehydration?  The reductions have both been proven as given in the Zn/Ni couple thread:

Post 270027 (Rhodium: "Zn/NiCl2 reduction of oxime/nitro/nitriles/ketone", Chemistry Discourse)

1) alpha,beta-Unsaturated acids (reduction to the saturated acid).

"Malic, crotonic, oleic, and cinnamic acid have been respectively transformed in succinic, butyric, stearic and phenylpropionic acids"

This shows that the alkenyl would be reduced to an alkane. 

"Formaldehyde, salicylaldehyde and vanillin has been reduced to methanol, salicylalcohol and vanillic alcohol. Salicylaldehyde forms an insoluble complex with nickel in ammoniacal solutions (4), its reduction has been furnished in the presence of potassium carbonate. The beta-keto-substituted phenylpyruvic and benzoylpropionic acid has been transformed to phenylacetic acid and gamma-phenylbutyrolactone respectively"

This shows the reduction of the aldehyde to an alcohol. 

../rhodium/chemistry /propiopropen.html
Post 211259 (Scooby_Doo: "Re: Phenylpropanol Dehydration", Chemistry Discourse)
These show the procedure for the dehydration of an alcohol with KHSO4

Post 345222 (Ritter: "dehydration reaction", Chemistry Discourse)
This is the dehydration with p-tosic acid.

In any case, we have formed allylbenzene as the major product with perhaps a little propenylbenzene. 

The remaining allylbenzene can be separated by distillation (don't really even have to separate the two) and then isomerization can be performed by the many ways discussed here and at Rhodium's site.

The oxidation from propenylbenzene to P2P is also well-covered.

(there are even methods that go from allylbenzene to P2P through the epoxide - and maybe others)
(Hive Bee)
05-30-03 19:32
No 436628
      After reading the posts     

Talking about the dehydration reaction:

I'm still not convinced. If someone can explain me the mecanism, then I will agree. From the posts I've read(your links) it doesnt seems that easy to do. As anyone done it with good success? No offense to Ritter or any other experienced bees.

If its not trough a primary carbocation, then how?

And if through a primary carbocation, since when are these stable? The energy barrier to create a  primary carbocation is really high and they to most purposes dont exist

Any ideas?
(Hive Bee)
05-30-03 20:12
No 436632
      How about a rearrangement to a secondary ...     

How about a rearrangement to a secondary carbocation, which is more stable? This rises a question: could the secondary carbocation rearrange further to a benzylic secondary carbocation, which would make propenylbenzene a side product of the reaction, maybe in amounts worth isolating.

fear fear hate hate
(Hive Addict)
05-31-03 21:06
No 436833

The basic idea behind this whole scheme is that I don't know anybody (relative to location) who can't get cinnaldehyde (cinnamon oil) in gallon quantities for a very cheap price.  Which means that if possible, and I think it is, that this is an excellent way to precursors. Perhaps more study into the the hydration reaction is called for in this case.
06-01-03 03:07
No 436880
      The textbooks say...     

gabd, just had a quick flick through the trusty o-chem textbook, and it seems, as I suspected, that primary alcohols can be dehydrated (the book suggests 170oC and 95%H2SO4, but as we all know textbooks arent the last word in what actually works in a practical setting... What it does say, however, is that while secondary and tertiary alcohols go via an E1 mechanism(and hence carbocation intermediate), primary alcohols go via E2 (no carbocation formed).  So dehydration should be possible under some conditions, anyway.
(Hive Addict)
06-01-03 03:52
No 436888

After looking in the books, you're right.  Also, ZnCl2/HCl can be used to chlorinate the substrate for elimination.  Or the tosylate can be made (easier, better yields, and better leaving group) but the tosylchloride may need to be purchased.  (it can be made from tosic acid.
Post 398337 (Aurelius: "Compilation of Acid Reagents", Chemistry Discourse))
tosyl chloride Post 311175 (foxy2: "Acid Chloride Synthesis", Chemistry Discourse)
Post 383271 (Aurelius: "Cyanuric chloride: -COOH to -COCl/COOR/CONR2", Novel Discourse)
../rhodium/pdf /trichloroisocyanuric.pdf

and apparently, the last document (the pdf) shows that coversion from the alcohol to the chloride is possible using the reagent discussed in that document. 

Basically, I still see no reason (although there may be one or two more steps involved) that this isn't a completely OTC and potentially cheap (this part may change) method to precursors.
(Hive Addict)
06-02-03 19:22
No 437256

> This patent might need a translation.

nope, it paraphrases exactly the abstract you posted.
(well, except for the Zn/Ni-couple generation tongue)
(Active Asperger Archivist)
12-13-03 07:13
No 476568

Dehydration is debatable, but elimination of the tosylate isn't that hard. 

Post 436456 (Aurelius: "Primary Carbon", Chemistry Discourse)

this gets us to the alcohol

Post 476352 (Rhodium: "TsOH/CoCl2: Tosylation of alcohols", Novel Discourse)

gets us the tosylate

simple elimination of the tosylate with base ought to do the trick to get the alkene.

Act quickly or not at all.
(Active Asperger Archivist)
05-13-04 01:46
No 506742
      3-Phenylpropanol US Pat 688359     

US Patent 688359

Improvements in or relating to Method for the Preparation of Aryl Substituted Primary Alcohols

This invention relates to a novel method for the prep of aryl substituted primary alcohols, and pertains more particularly to the preparation of such alcohols by the hydrogenolysis of 4-aryl-1,3-dioxanes.

Ar is an aryl radical, and R is hydrogen or hydrocarbon and may be the same or different.  The 4-aryl-1,3-dioxanes are prepared by reacting formaldehyde with stryrene or substituted styrenes according to the method described by Shortridge, JACS, Vol. 70, p873 (1948).  By the hydrogenolysis of the 4-aryl-1,3-dioxanes there are obtained in extremely high yields and purity, aryl substituted alcohols.  The hydrogenolysis proceedes as depicted below:

Among the 4-aryl-1,3-dioxanes which may be used to give aryl substituted alcohols are included 4-phenyl, tolyl, naphthyl, etc. The preferred dioxanes are those in which each R is hydrogen or a saturated hydrocarbon radical containing from 1-6C.  The hydrogenation is carried out below 200*C. 

Example 1: 3-phenylpropanol

A mixture of 104 pts styrene, 333 pts 37% aq. Formaldehyde, 28.6pts of 96% sulfuric acid is refluxed and stirred for 16 hours.  The org. layer is washed successively with dilute sodium carbonate, sodium bisulfite and water.  The product is dried by azeotropic distillation with 88 pts benzene and vacuum distilled.  90% 4-phenyl-1,3-dioxane  that has BP: 95*C/2mm; Nd25 = 1.5288 and d25 = 1.101

656pts the dioxane above and 132pts of palletized copper chromite are charged into a stainless steel rocking autoclave.  After purging the bomb with hydrogen at 4100 psi the temperature is brought to 175*C for 8 hours.  Then the mix is cooled, washed out with methanol, filtered and distilled.  529pts of 3-phenylpropanol (96%)

Act quickly or not at all.
(Chief Bee)
05-13-04 02:15
No 506746
      4100 psi??? That would be >250 atm ...     

4100 psi??? That would be >250 atm pressure!

The Hive - Clandestine Chemists Without Borders
(Active Asperger Archivist)
05-13-04 02:31
No 506751

you don't have to use the hydrogenation procedure given- try a mild procedure and see if the product reduces in the same manner.  If it weren't for the high pressure this is a decent method for obtaining P3Pol.

Act quickly or not at all.