Thanks Ritter! This great write-up right on the heels of Beaker's 2C-B is wonderful. I wonder what the 2C-H yield using this method to directly reduce 2,5-DMNS would be???
Thanks too to CHEM_GUY for enlightening the Hive to the benefits of Urushibara, and for answering my dolt-like questions regarding same offline!
could you also increase yeilds by placing the beaker into an ultrasonic cleaner bath, thereby sonicating it as well? see old hive for great ultrasonic info
I'm glad it worked for you Ritter and thanks for the props! The write up is excellent, and the commentary worth while. Great job.
That Ultrasonic crap:
From "The Journal of the American Chemical Soceity", yr 1987, Vol 109,
pages 3459-3461
"Hetrogeneous Sonocatalysis with Nickel Powder
We have discovered that ultrasonic irradition of Ni powder increases
it's activity as a hydrogenation catalyst by >10^5. ...
The use of high-intensity ultrasound to initiate or enhance both
homogeneous and hetrogeneous chemical reactions has been under
intense investigation [1-7],...
Simple Ni powder is an extremely inactive catalyst for hydrogenation of
alkenes. Even after 2 X 10^4 min, no alkanes are deteacted with rapid
stirring under 1 atm of H2 at 273 K (i.e., <10 nM/min). In comparison
under the same conditions, if the nickel was first irradiated with
ultrasound [12], 1-nonene is hydrogenated at millimolar per min rates,
as shown on Figure 1. Ultrasonic pretreatment of ~1 h gives optimal
activity, which decreases with longer irradiation. The hydrogenation
activity is quite general and shows little dependance on the choice of
alkene... ; no reduction of ketones or aldehydes was observed.
Other methods of creating active Ni catalysts exsist [13]. The thermal
hydrogenation rates at 1 atm of H2 and 273 K with high surface area Ni
sponge (Raney Ni [13a], Aldrich Chemicals, grade W-2) are comparable
to those obtained eith ultrasoniclly activated Ni powder. Compared to
Raney Ni, however, our activaed Ni powder is more selective
(C-O double bonds are untouched), much easier to produce, and much
simpler to handle (nonpryophoric). Activation of Ni powders by H2 at
150 C and 10 atm will also generate reactive catalysts [13b], which
rapidily lose activity upon exposure to O2.
..."
[1] Adv, Organomet. Chem. 1986, 25, 73. (b) Modern Syth. Methods 1986,
4, 1. (c) Ultrasound: Its Chemical, Physical and Boilogical Effects
1987. (d) J Chem. Ed. 1986, 63, 427. (e) Ultrasonics 1985, 23, 157.
[2] J. Am. Chem. Soc. 1983, 105, 5781. (b) J. Am. Chem. Soc. 1983,
105, 6042. (c) High Energy Processes in Organomettalic Chemistry,
American Chemical Society 1987, p 191.
[3] High Energy Processes in Organomettalic Chemistry, American
Chemical Society 1987, pp 209-222. (b) Organometallics 1986, 5, 1257.
(c) Nachr. Chem. Tech. Lab. 1983, 31, 797. (d) J Org. Chem. 1982,
5030.
[4] Ultrsonics 1987, 25, 40. (b) Tetrahedron Lett. 1986, 27, 3149.
(c) J. Org. Chem. 1985, 50, 910, 5761. (d) J. Amer. Chem. Soc. 1980,
102, 7926.
[5] Angew. Chem., Intl. Ed. Engl. 1983, 22, 728. (b) J. Am. Chem. Soc.
1984, 106, 6856.
[6] Ultrasonics 1987, 25, 45. (b) J. Lab. Pract. 1984, 33, 13 and
references therein.
[7] Tetrahedron Lett. 1986, 27, 415. (b) J. Am. Oil Chem. Soc. 1983,
60, 1257. (c) Chim. Ind. (Milan 1968, 50, 314.
[12] All sonications were performed with a Heat Systems-Ultrasonics
W375 cell disruptor with a titanium immersion horn at acoustic
intensties of ~50 W/cm^2 at 20KHz, as described elesewher in
detail [2]. Irradiation in a low-intenstity ultrasonic cleaning bath
does give hydrogenation, but at greatly reduced rates. Hydrogenation
reactions were carried out at 273 K under 1 atm of H2. In a typical
reaction, 1 g of Ni powder (200 mesh, EM Science, Cherry Hill, NJ
08034) was added to a 10% solution of alkene in octane. ...
[13] Reagents for Organic Synthesis 1967, by Fieser, L. F., Vol. 1,
pp 723-731. (b) Thomas, C. L., Catalytic Porcesses and Proven
Catalysts 1970, pp 126-133. (c) Somorjai, G. A.; Chemistry in Two
Dimensions: Surfaces; 1981, pp 445-447 (d) J. Phys. Chem. 1983, 87,
915. (e) High Energy Process in Organicmetallic Chemistry,
... pp 223-245.
Read my Disclaimer:
http://cantsueme.homestead.com (http://cantsueme.homestead.com)
Would neutralizing a Nickle Carbonate from a potters supply with HCl and then reducing, yield the Nickel chloride hexahydrate required for this catalyst?
I know you mentioned regular reynolds wrap, but purely out of curiosity does the Al thickness have the same relationship to the RXN that it does with Al/Hg reductions? ei can the RXN be slowed or speeded up by varying foil thicknesses?
What are the pitfalls a novice chemist might anticipate in pursuing this route?
Thanxs again for blazing a new trail fer us bees
Life is a dream (until someonew wakes you up)
If that synth doesn't belong on Rhodium's site, then I don't know what does ! It's official folks, the war on drugs is a joke. Good job Chem_Guy !!
}>
If there really was a God, I would have been forwarded to Hell a long time ago.
This is a trully awesome reduction. Not touchy at all. A FOAF triied it on TMP2NP, temps were up to 60-70C during catalyst prep. The catalyst was not isolated , just 3ml of HCl was added after catalyst prep, to activate. Not even certain that precipitation had finished, but hydrogen evolution had stopped. Temps were in the mid-high 60s throughout reduction which only took 3 hours.
Yield was 60+%. (closer to 50% after clean up) Way cool for the 1st kick at the can. I am impressed! Its all OTC!
Question though. could methanol be substituted for the ethanol? Be easier to control temperature that way.
BTW - FOAF found that temp increased with stirring as did hydrogen evolution (causing beaker to foam over). something to keep an eye on.
Also to avoid Ni at interface while separating layers toss a magnetic stir bar in and stir with the NaOH douse. All the Nickel will stick to it, then you simply transfer the stirbar w/ nickel to beaker of HCl and stir to regenerate your NiCl2(H20)6. (takes a couple days though) Probably a little Al goes over to, Oh well.
Curious though, there is a white precipitate in the HCl as well, is this Aluminum Chloride? Be sweet if Alumninum Chloride isn't H2O soluble cuz it'll make seaprating the Ni easier.
Antibody is wearing one big assed smile!
Just gone.
Bingo! This is very good stuff. Thank you Ritter! :)
"Dissolve 5g pure phenyl nitropropene in 50ml Ethanol and add to nickel soln."????
If the 5%NaOh was decanted off the percipitated Ni then washed with water how is there a solution. Is the Ni first placed into some EtOH? Or is the nitropropene/EtOH added directly to the ni.powder?
add it directly to the nickel after decanting the activation solution. Your rxn will get very viscous as it progresses, requiring the addition of more EtOH. It wouldn't hurt your rxn to bring your volume up to 125mls EtOH. You will still end up with a viscous slush at the end. If you look on Rhodiums page you will see my variation of this same rxn for TMA-2. Check solvent volumes there.
happy redxns :)