Russian patents works!!! Zn-HCl nitrostryrene rdxn

[sunlight]

I've been may be too much enthusiastic, and now I'm worried remebering my first test with MDA, that yielded a 60 % that never happened again. I've done more tests with this procedure, but with less Zn, and yield has been constantly a bit more than a 30 %. I must repeat my first test, or similar, with big excess of Zn and a accurate work up and see then what happens.
In my first I didn't dry the solvents and it was a big volume of solvent for little product, so it had (confirmed) NaCl impurities (saline wash) ... well, it was just a test. So please, wait a confirmation of more realistic yields. What I can really say right now is that a 30%+ is easily achieved with a 3:1 Zn/nitro w/w, this is totally sure, but it's not enough good. I have been very enthusiastic with the finding, it works, but the yield can be lower. Sorry if it is not so good.

[Vibrating_Lights]

Has Sunlight tried a Mdp2np reduction with 6:1 Zn:Nitro ratio yet. Also what is the correct procedure for the work up. Is the alcohol in the rxn removed with vacume then basified with NaOh.  Followed by extraction with Toulene.

[sunlight]

We went to the house of a friend some days ago and we made a bit of the nitropropene from iso, with the nitrosite procedure. It was the first time for us, and the final product had a strange smell that remebered me other smells and make me think that the product was not pure. The rxn went exactly like with 25DMNS, but always with that strong smell in the flask. We made a TLC MeOH:NH3 of the rxn mixture, with 2,5 DMNS I have observed that there's a big spot at the bottom, probably all Zn salts, and a single spot a bit higher corresponding to 2CH, in this case we forgot the TLC and solvent arrived to the top, so when we rembered it some time later, we saw the spot in the bottom and a single spot, but rf was around 0.6 instead of around 0.2, and we don't know if this diference can be explained due our forgetfullness, if it was the amine, the rxn worked really well.
When finished, and aliquot was basified with 40 % NaOH and clearly appeared drops of oil floating, but I couldn't recognize the smell of amine due the strong persistent smell of the beginning and I had to come back home. After almost two weeks he have not tried xtallization, but he has told me that pH of dried solvent is not significatively basic. Too much time to process it, he should end work up the same day, now everything can be destroyed, I'm dissappointed, he works really ssllllooooowwwwwww. The rxn went apparently pefect, so I would say it worked, but I was not there in the work up and my friend is not really experienced, may be he made a mistake or may be it did'nt work.
I made at home a very small test with 3,4,5 TMPNP, the rxn worked the same, dissapearing the insoluble nitro when Zn was 2-3:1, and basifying appeared the oil with the characteristic amine smell. I'm optimistic, but I can't state it works, and I won't try it at the moment, so if you can, it would be nice to make a small test with 34MDPNP.
I would start with a 5 % HCl in the flask and I would end with a 9 % based in free HCl over total weight, 2 hours addition, better 7:1 Zn, and then evaporate alcohol with aspirator, add water to have a density that let work DCM wash (d~1.2), basify with NaOH 40 + % to reduce volumes, extract... If you want precise details, PM me.

[Cyrax]

Sunlight, I am glad that you tried the reaction on a nitropropene.  Since quite a while, I was wondering if it could work.  A method to be sure of the spot on the TLC, is to do a ninhydrine test.   If you like, I'll look up how to make this spray.  To use the spray is really easy: spray the stuff on your TLC, let it dry, heat it in an oven and if you have an amine, there will be a coloured spot on the TLC.  Ninhydrine is a messy substance, once I had to make the spray and it was not easy to weigh the correct amount.  This stuff sticks to everything and it is carcinogenic .

I did some quick stoichiometry and I guess the reaction goes like this:
 4 Zn  +  8 HCl  +  Ar-CH=C(NO2)-CH3  -->  Ar-CH2-CH(NH2)-CH3  + 2 H2O  +  4 ZnCl2

Of course, it is wise to use excess Zn.

If the trouble with this reaction persist, I have an other method that first reduces the nitropropene to the oxime with Pb - DMF/AcOH.  Then, there will be no problem reducing the oxime to the amphetamine with Zn / AcOH.  The problem with the Pb reaction however is the amount of solvent that you have to use (maybe you can use less solvent).  If I remember correctly, for 10 mmol of the nitropropene, you have to use 2 eq. of lead powder (this is OK), but 75 ml (!) of DMF and 5 ml of AcOH.
This can be a good method for recreational use, if you want to make DOB or DOI.  In the article, they get 92 or 94 % (I do not remember correctly) of phenyl-2-oximopropane from phenyl-2-nitropropene.

[Antoncho]

Just wanted to remind you guys this

Post 70459 (missing)

(yellium: "Syn. Comm 18(7), 693-697 (1988)", Novel Discourse), posted by Yellium - anyone knows what ever came of it? I remember someone saying that this redn was successful w/50 g 2,5-DMNS, and another one said it didn't work when he tried it. - so the question still hangs open.

Well worth trying, IMHO.

Edit:As a side note, could anyone give me a clue where one can find an experimenal procedure of a nitropropane reduction to amine w/Al/Hg - i remember someone reporting a success (think pseudonitrosite NP --> nitropropane w/NaBH4 a la Beaker ), but can't find it for anything in my life.


Antoncho

[Rhodium]

Ritter said it did produce a lot of tar when performed on a larger scale than a few millimol, but on the scale in the paper it worked great. It might just be a matter of tweaking rxn conditions.

[___]

Cyrax - i'd wouldn't mind hearing more about >Then, there will be no problem  reducing the oxime to the amphetamine with Zn / AcOH.  can you elaborate?

[Cyrax]

Sunlight's Zn/HCl procedure is EXCELLENT to convert aryl-2-nitrostyrenes to amines, but it doesn't work for nitropropenes.  Thus we have to get some intermediate product like an aryl-2-oximopropane.  The Pb - DMF/AcOH procedure is original, convenient, and you don't need suspicious chemicals.
Example:
 Phenyl-2-nitropropene (0.1 mol) was dissolved in a mixture of acetic acid (5 ml) and DMF (75 ml), and lead powder (2 eq.) was added.  The mixture was stirred at ambient temperature for 2 h.  The mixture was poured into ice-water and extracted with Et2O.  The ether solution was washed successively with an aq. NaHCO3 solution and an aq. NaCl solution, and then dried over MgSO4.  The solvent was evaporated off and the resultion phenyl-2-oximopropane was purified by chromatography (silica gel / DCM).  Yield: 92 %.
Ref.: Synlett (1990) p 477

Chromatography is tedious, but in Chem. Ber. (1981) 114;12 p 3813 they crystallize phenyl-2-oximopropane in hexane.

Then you can do different things with your precious oxime:
 * a Na/EtOH reduction like in JOC (1964) vol 29 p 1419 (there is an excellent example on Rhodium's site)
 * a Zn/AcOH reduction like in Vogel (5th ed.) p 1151
or like in the russian patent, this time not on the nitrostyrene but on the oxime.

I found this Zn/AcOH reduction somewhere on Rhodium's site:
 At room temperature with stirring, zinc dust (74 mg) was added to a solution of the oxime (44 mg, 0.185 mmol) in 2 ml glacial acetic acid.  Stirring was continued for another 15 minutes.  The reaction mixture was filtered through a sintered glass funnel with suction.  The filtrate was concentrated under vacuum to afford the amine as an oil (37 mg, 0.166 mmol, 90 % yield)

And if you don't like the oxime, you can hydrolyse it with HCl to the aryl-2-propanone.

I made a VERY BIG MISTAKE in my previous post ():-).
Ninhydrin DOES NOT work on amines, but on amino-acids.

[Antoncho]

This lead/DMF procedure - is excellent, i've been looking for it for a long while! (i collect'em )

Antoncho

[hest]

Ninhydrine works nice on amines (might heat it a bit)

[sunlight]

Are you sure it does not work with nitropropenes ? A friend told me he got some MDA. It was a low yield, like a 10 %, but he delayed the workup weeks, and I think it could destroy some product. In other hand I have not evidence it was MDA, only his word.

[Cyrax]

I am not sure it didn't work.  I just saw that your friend had some problems with the reaction.  It would be beautiful if you or some other friendly bee could optimize the reaction for nitropropenes.  This would be great and in each case much better than the 2 step procedure that I proposed.  I only meant: if the yields don't improve, you could consider the Pb - DMF / AcOH reaction.

Keep up the good work! The Zn-HCl is a kick-ass reaction.

[Xgoddess]

A research professor I know attempted the Zn/HCl redn for 10 g of 345 tri-methoxy-phenyl-2-nitro propene. He got no TMA at all. He is a bit concerned that the redn does not work for nitro propenes, only nitro styrenes. The reduction needs to be tweaked a bit::for example, these professors dont care for chromatography...What about a one step LAlH redn??

[___]

goddess, i think you are missing the point, the whole idea here is find ways around watched/controlled chemicals, otherwise this site would be a tit on a a bull.

2X now bees claiming it doesn't reduce nitropropenes, be nice to know what it is Zn/HCl doing to nitroproenes. Is it cleaving the double bond? to give the ethane, is it only reducing to the oxime? "It doesn't work" doesn't tell us much. Can your professor expand on  "He got no TMA at all"?

[sunlight]

I need time to check it. As it has some similarities with the Fe CLH conversion of nitropropenes with acetones I was worried about it, but when I made a 250 mg 345TMPNP it seemed to work, basifyng I smelled to the amine. I'll try it to see if it is true or not.

[Vibrating_Lights]

If all yall are afraid to fuck with sunlights Zn procedure and use shulagins procedure in Phikal 109 with Fe/AcOH yeilds from nitropropene to ketone 80% then a MMNitro thats pretty Otc.  can't believe it is not talked about more. with 99% yeild saf ->Iso  -> 85%%nitropropene ->80% ketone dont think that can be beat. Besides the nitrite all OTC.  Has any one ever tried to oxidise safrole or isosafrole with a nitrate yeilding an epoxide or a ketone and nitrite much the same as the procedure using lead to reduce nitrate to nitrite.  just replace the lead with alkene.  Mabye use a equimolar ammount of nitrate in dh20 perhaps with a.  wouldnt it be crazy if ammonium nitrate could be used and as the ketone is formed it condenses with the ammonia yeilding the oxime.  Mabye swimis just high and rambling. 
VL_

[Antoncho]

85%%nitropropene ->80% ketone dont think that can be beat

heh...  Practically, it means 2 steps instead of 1...

And that means a lot (IMHO)

Also, the actual yields are usually lower that in theory. Sometimes much lower .

Antoncho

[sunlight]

Yo are right antoncho, my yields with Zn HCl are far from the patent. And it is similar in a lot of procedures.

[Vibrating_Lights]

We believe that the loss in yeilds with pseudonitrosite are due mainly to high temps causing the decomp to the red goo. yeilds can remain high if the temps are closely monitered.  The secret to cleaning that red goo from the flask.  AcOH and Actone. or ethyl acetate. Ice Baths are the key. Ps.don-t get that shit on you. it will make your skin rough like a wart whereever it touches.
Vl_

[Antibody2]

sunlight -this still blows me away

VL - the pseudonitrosite route produces nitropropenes, which have not been sucessfully reduced using this rxn. The red goo you refer to is more indicative of low grade solvent and impure propenylbenzene, although ice is still necessary.