bones (Stranger)
05-05-03 11:59
No 431519
      3,4-methylenedioxyphenyl)-2-nitropropene to mdp2p?     

hi everyone.. decided to skip the friendlies and get right to the chemistry...

anyway.. has this route been tested?  pihkal uses iron..that works fine in my dreams.. but this seems like a good alternative when iron powder isnt avaliable.. plus the yield has been reported to be quite good... anyway.. if anyone has tried this id luv to hear some reports... i hope it hasnt been discussed too much... i did a search but i couldnt find anything relevent... but i might have ballzed that up... new here so cut me some slack..

from the description the rxn seems to run clean and produce a very pure ketone... always a good thing

anyway.. heres the synth..

 25g (0.12 mols) 1-(3,4-methylenedioxyphenyl)-2-nitropropene was dissolved in 350ml methanol in a 500ml Erlenmeyer flask situated on a magnetic stirrer, and chilled to -10C with an ice/salt bath. Then, with
good stirring, 9.2g (0.24 mols) of NaBH4 was added a little at the time, not allowing the temperature to rise above 15C. It fizzes some as the sodium borohydride dissolves, and the solution will change color. When
the generation of heat had subsided, the ice/salt-bath was taken away and the solution was allowed to stir at room temperature for two hours.
Then the solution was cooled to 0C with an ice/salt-bath, and then 125ml 30% hydrogen peroxide was added with good stirring (the exact concentration of the H2O2 is not critical). With this addition a white, sticky precipitate formed. 35g potassium carbonate was then added, the
ice bath removed, and the stirring was continued for 18 hours at room temperature (*). After this time, the solution was transferred to a 1000ml Elenmeyer flask, and slowly acidified with 2M HCl with good stirring, and care being taken for the evolution of heat and CO2. About
450 ml of acid was needed. The color of the solution turned from a orange-tinted yellow to a green-tinted yellow at this point. The solution was checked with pH paper just to be sure. All of the precipitate should
also be gone at this point, if not, continue the stirring for a while. The solution was divided into two portions of about 500ml each, and each half was extracted with 3x50ml CH2Cl2, and the pooled extracts (a yellow solution) was washed with 2x100ml dilute NaOH solution and then 100ml
H2O. The first NaOH wash was deep red, the second one slighty yellow, and the water was colorless. The organic phase was dried over some Mg2SO4. The solution was filtered with suction, and the solvent distilled off at atmospherical pressure. The residue was 21.6g of a
clear yellow oil with a weak smell. The oil was distilled at 2-3 mmHg, and the product came over at 110-125C, and the yield was 18 grams of a water-white oil, or 84% of theory. The oil turned slightly yellow over the next couple of days, but after that the oil never aquired a deeper color.


where i live it might be a struggle to get salt ice to -10... but im sure i can find a appropiate liquid that will... anyway... if anyones got thoughts id appreciate it..
cheers

bones
 
 
 
 
    bones
(Stranger)
05-05-03 12:03
No 431520
      oh..     

oh.. i just noticed this synth was posted by rhodium... well... it must be here then... can someone direct me to the thread?

cheers ... oh.. and sorry if this is a repeat thread... as i said... i couldnt find it via the search
 
 
 
 
    GC_MS
(Hive Addict)
05-05-03 14:06
No 431534
      if...     

If I want to convert nitropropenes to propanones, I usually apply Ba's method, which can be found at ../rhodium/chemistry /p2p.sncl2.html.

This method gave me good results and clean products in the past.

The faster you run, the quicker you die.
 
 
 
 
    Rhodium
(Chief Bee)
05-05-03 20:27
No 431568
      H2O2/K2CO3 Nef reaction     

You are probably looking for ../rhodium/chemistry /phenylacetone.html#p2np

The procedure is not reccommended for methoxy- and methylenedioxy substituted phenyl-2-nitropropenes, as they tend to give low yields when they oxidize further to phenylacetaldehydes, benzaldehydes and benzoic acids. The yield is OK for P2P though.
 
 
 
 
    bones
(Stranger)
05-06-03 01:44
No 431616
      ok... so rhodium did you or did you not post...     

ok... so rhodium did you or did you not post this method?  heres a link for the full write up from pip to md p2p? .... http://www.lycaeum.org/forums/alchemy/Messages/339.html

the yields seem good on this... but many posts are missleading on their viable yields? ... oh  and thankx for the info guys :D
 
 
 
 
    Rhodium
(Chief Bee)
05-06-03 01:58
No 431621
      Me?     

I do not recall having posted a version of it adapted to the production of MDP2P... Already in 1998 I wrote in Total Synthesis II about the oxidative side reactions happening when using this procedure on substituted phenyl-2-nitropropenes - you will get a good yield of a yellow oil when performing the procedure on such substrates, but it contains very little MDP2P and a lot of other things. 

The lycaeum link above does not work, by the way.
 
 
 
 
    bones
(Stranger)
05-06-03 03:39
No 431643
      the link seems fine from here ?? dunno     

so heres the entire message.. apparently posted by you rhodium,... but then it was in 1997 so youre forgiven for having a hazy memory :D .... ill give the protocol a few tries in nmr tubes ... if successful ill scale up a touch and share my results ... it just seems like a viable method to me... but if you say there are many side reactions then perhaps it is not.... will do a few microscales and get back ... heres the entire post


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The Alchemist's Den
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Subject: High yield prep of MDP2P from Piperonal
From: rhodium@nym.lycaeum.org
Date: October 02, 1997 at 12:55:30
------------------------------------------------------------------------


When visiting my local university library I found these lab notes on a
crumbled piece of paper lying in a waste basket. It details a high yield
synthesis of MDP2P from piperonal. Peculiar things one can find, indeed.

Preparation of 1-(3,4-methylenedioxyphenyl)-2-nitropropene

        15g of piperonal was dissolved in 40ml of MeOH under stirring in
a 250ml Erlenmeyer flask. When all of the piperonal had dissolved, 7.1g
nitroethane was added to the solution. The flask was put in a ice/water
bath with magnetic stirring, and when the temperature of the solution had
dropped to 0C, a solution of 4g of NaOH in 20ml distilled water (which
had been pre-chilled to 0C) was added portionwise to the solution, at
such a rate that the temperature never exceeded 15C. A white precipitate 
formed (it may cake in the flask when the temperature drops again, and
must be broken up again with a glass rod or equivalent). The stirring was
continued for one hour, and then 100 ml chilled distilled water was added
to the solution. More of the white precipitate formed. The whole slurry
was poured into a pre-chilled solution of 15ml 30% HCl in 85 ml water in a
500ml Erlenmeyer flask. The flask was swirled gently, and there was slight
bubbling and fizzing, and the color shifted from white to blue to green
to yellow in a minute. Quite spectacular! When the fizzing subsided,
the solution was put back in the ice/water-bath with magnetic stirring.
When the temperature has dropped to about 5C the solution was clear, with
yellow granules at the bottom. This was the crude product. The solution
was filtered with suction, and the yellow granules was put in a 100ml
beaker, and hot (but not boiling) water was poured over them. The crystals
melted, and unreacted piperonal floated at the surface. The bottom layer,
consisting of the pure nitrostyrene, was collected with a pasteur pipette.
(a disposable plastic pipette was used for this maneuver, in a glass
pipette the nitrostyrene is likely to crystallize. Otherwise, just decant
the water and piperonal from the product). The nitrostyrene was poured on
a watch-glass and was let to crystallize in the refrigerator. The canary-
yellow crystal cake was crushed, and air dried on a filter paper. The
yield was 13.15g, or 67% of theory. This nitrostyrene should be used
within a week, or stored in the cold, as the color fades to a slight
orange over a couple of weeks in room temperature, which is a sign of
decomposition.

Preparation of 1-(3,4-Methylenedioxyphenyl)-2-propanone (MDP2P)

        25g (0.12 mols) 1-(3,4-methylenedioxyphenyl)-2-nitropropene was
dissolved in 350ml methanol in a 500ml Erlenmeyer flask situated on a
magnetic stirrer, and chilled to -10C with an ice/salt bath. Then, with
good stirring, 9.2g (0.24 mols) of NaBH4 was added a little at the time,
not allowing the temperature to rise above 15C. It fizzes some as the
sodium borohydride dissolves, and the solution will change color. When
the generation of heat had subsided, the ice/salt-bath was taken away
and the solution was allowed to stir at room temperature for two hours.
Then the solution was cooled to 0C with an ice/salt-bath, and then
125ml 30% hydrogen peroxide was added with good stirring (the exact
concentration of the H2O2 is not critical). With this addition a white,
sticky precipitate formed. 35g potassium carbonate was then added, the
ice bath removed, and the stirring was continued for 18 hours at room
temperature (*). After this time, the solution was transferred to a
1000ml Elenmeyer flask, and slowly acidified with 2M HCl with good
stirring, and care being taken for the evolution of heat and CO2. About
450 ml of acid was needed. The color of the solution turned from a
orange-tinted yellow to a green-tinted yellow at this point. The solution
was checked with pH paper just to be sure. All of the precipitate should
also be gone at this point, if not, continue the stirring for a while.
The solution was divided into two portions of about 500ml each, and each
half was extracted with 3x50ml CH2Cl2, and the pooled extracts (a yellow
solution) was washed with 2x100ml dilute NaOH solution and then 100ml
H2O. The first NaOH wash was deep red, the second one slighty yellow,
and the water was colorless. The organic phase was dried over some
Mg2SO4. The solution was filtered with suction, and the solvent
distilled off at atmospherical pressure. The residue was 21.6g of a
clear yellow oil with a weak smell. The oil was distilled at 2-3 mmHg,
and the product came over at 110-125C, and the yield was 18 grams of a
water-white oil, or 84% of theory. The oil turned slightly yellow over
the next couple of days, but after that the oil never aquired a deeper
color.

(*) With the addition of K2CO3 and H2O2 the mixture becomes quite thick,
    so your magnetic stirrer may not be able to handle it. Use a
    mechanical stirrer instead here, or help your poor mag-stirrer for
    one or two hours with occasional stirring with a glass rod and
    swirling of the flask. Some of the precipitate may cling to the
    walls of the flask too, so loosen that up too. In 2-3 hours the
    precipitate is much looser, and any mag-stirrer can be used
    thereafter.

References:

Step 1: Practical Organic Chemistry, Vogel, 5th Ed.
        Pihkal, Shulgin & Shulgin 1991, #100.

Step 2: Synthesis 723-726, July 1994
        Pihkal, Shulgin & Shulgin 1991, #109.

Shulgin's yield in the first reaction is 54% and 80% in the second, which
gives an overall yield of 43%. The corresponding yields in this synthesis
is 67% and 84%, and the overall yield is therefore 56%. This synthesis is
also much simpler to carry out, and employs less harsh reaction conditions. 

Rhodium

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Replies:

* Re: High yield prep of MDP2P from Piperonal et2o 09:38:32 10/03/97 (0)


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    Rhodium
(Chief Bee)
05-07-03 03:15
No 431811
      I retract that Lycaeum post     

Jeez, they still have that thing left? Can't everything I wrote in my teens please vaporize?

One clue that the rxn never worked correctly is that the product was water-white when distilled and not yellow as it should be - thus it contained mostly other by-products and not MDP2P.
 
 
 
 
    mellow
(Hive Bee)
05-28-03 18:21
No 436096
      Does it work up to the Knoevenagel part?     

Does it work up to the Knoevenagel part? Which base is prefered: NaOH | NaOAc - these are the only ones I can get.

Is this a suitable reduction: ../rhodium/chemistry /mdp2p.piperonal.html

No fancy suggestions please. I can only get OTC chems.
 
 
 
 
    mellow
(Hive Bee)
05-28-03 18:26
No 436100
      "An iron reduced with hydrogen was used"     

The previous URL ../rhodium/chemistry /mdp2p.piperonal.html says "An iron reduced with hydrogen was used"

How do I change plain iron powder into "iron reduced with hydrogen" - otherwise how can I make it.
 
 
 
 
    Rhodium
(Chief Bee)
06-02-03 00:59
No 437068
      you simply want clean iron powder     

The preparation of 3,4-methylenedioxyphenyl-2-nitropropene from piperonal works as stated (recrystallize from isopropanol to purify and increase its shelf-life), and very likely the NaBH4 reduction of that to 3,4-methylenedioxyphenyl-2-nitropropane too, we just need to use another variation of the Nef reaction ( R1R2CH-NO2 R1R2C=O ) than H2O2/K2CO3, as this substrate seems to be too sensitive for such treatment.

Iron Powder: It doesn't actually need to be "reduced by hydrogen", you simply want iron powder free from oil and any iron oxides (both red rust and black iron oxide), i.e. not just any iron filings found on a machine shop floor.
 
 
 
 
    LaBTop
(Daddy)
06-02-03 13:23
No 437199
      Link     

http://www.micronmetals.com/iron.htm
iron metal powder, hydrogen reduced, $ 11.80 per 1-2 pound.  CHEAP.

You really need very clean iron powder for this synth.
 
Webster Dictionary:
""(Chem.) To bring to the metallic state by separating from impurities; hence, in general, to remove oxygen from; to deoxidize; to combine with, or to subject to the action of, hydrogen; as, ferric iron is reduced to ferrous iron; or metals are reduced from their ores; -- opposed to oxidize.""

Steam is decomposed when passed over heated iron.
                3 Fe  +  4 H2O   <==>   Fe3O4   +   4H2
The action of iron on steam is reversible, depending on the experimental conditions:

1. H2 gas production:
Spongy iron from the reduction of spathic iron ore (ferrous carbonate) is heated to redness and steam passed over it.
                3 Fe  +  4 H2O  ==>   Fe3O4  +  4 H2

(This is one of many ways to produce hydrogen gas).  

2. Metallic pure Fe production:
The hot ferrosoferric oxide, Fe3O4, is reduced with water-gas:

Fe3O4   +   4 H2   ==>   3 Fe  +  4 H2O
                Fe3O4 + 4CO ==> 3 Fe + 4 CO2
 
Water-gas is made by passing steam over red hot carbon and it consists of a mixture of carbon monoxide and hydrogen, with a smaller amount of carbon dioxide:


   bright-red     
      heat       
C   +   H2O   ==>    CO  +  H2 

     dull-red       
heat
C   +   2 H2O   ==>   CO2  +  2 H2

When hydrogen is passed over many heated metallic oxides (e.g. copper oxide, iron oxide, or lead oxide), they are reduced to the metals, f.ex.:

CuO   +   H2   ==>   Cu   +   H2O

Better buy it. LT/

WISDOMwillWIN
 
 
 
 
    Osmium
(Stoni's sexual toy)
06-03-03 17:01
No 437542
      The point is that normal, industrial grades of     

The point is that normal, industrial grades of iron are actually 'steel', or in other words iron alloys. of course you don't want to use them, if possible, although they might work just the same. Another important thing is that technical iron always contains carbon. Ever dissolved cast iron in an acid? Lotsa black shit left over. That's why you want chemically pure iron powder. It doesn't have to be reduced by hydrogen. A common, relatively pure form of iron is 'electrolytic iron', which seems to be purified by electrolysis or is suitable for galvanic iron plating.

I'm pretty sure that most iron grades available from chemical supplier will work just fine.

I'm not fat just horizontally disproportionate.
http://www.whatreallyhappened.com
 
 
 
 
    heavenadisaster
(Hive Bee)
04-28-04 07:24
No 503432
      would the Fe/HCl rxn of mdp-nitropropene to...     

would the Fe/HCl rxn of mdp-nitropropene to mdp2p work for mdp-nitropropane to mdp2p?
 
 
 
 
    Rhodium
(Chief Bee)
04-28-04 11:26
No 503466
      I'd suggest the Nef reaction in that case     

Not as good as a Nef reaction would: Post 499825 (Rhodium: "A very comprehensive Nef Reaction Review", Novel Discourse)

A plain nitroalkane (as opposed to a nitroalkene) may be reduced to a mixture of amine and ketone with iron, see Post 437252 (Lego: "... and now a practical application", Novel Discourse)

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