Author Topic: Problems reducing phenyl-2-nitropropene to P2P -dreamer  (Read 3300 times)

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Problems reducing phenyl-2-nitropropene to P2P -dreamer
« on: April 20, 2000, 08:38:00 PM »

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Author  Topic:   Problems reducing phenyl-2-nitropropene to P2P 
dreamer
Member   posted 06-03-98 08:40 PM          
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Dream 1:
0.6mol 32gr powdered Fe was heated in 140ml 96% technical acetic acid. After 10min on the steam bath there was no sign of a reaktion between Fe and acetic acid. 0.1mol 16.3gr phenyl-2-nitropropene in 150ml 96% acetic acid was added. The color of the mixture was yellow, after 2h on the steam bath the color changed to black and on the bottom there were black solids. I didn't see any white iron acetat (shulgin #98). All was transfered in my 2liter separating funnel and 1.5l H2O were added. The black solids dissolved and the whole shit was filtered, made basic with NaOH and the extracted with 2*75ml Ether. The ether was eliminated and i got 10ml of a waterlike solution with acetic acid smell. I tested with bisulfite, no sign of a ketone.
Do i have to use anhydrous acetic acid ? (glacial acetic acid =99.9% acetic acid ?)
When does the reaction between acetic acid and Fe start?
Is it dangerous to heat the whole mixture for 2h on a steam bath?

Dream 2:
31gr 0.58mol powdered Fe and 23 ml H2O were heated on a steam bath. When the temperature of the mixture was 80° i added 3gr phenyl-2-nitropropene. The crystals melted. I added 1ml 31% HCl. A lot of bubbles were generated from Fe. I added 13gr phenyl-2-nitropropene and 6ml 31%HCl. All was refluxed for 2h on a steam bath. At the beginning the color of the melted crystals changed from yellow to brown, with Fe at the bottom of the flask, but when the mixture began to reflux the Fe dissolved and i got a black mixture, no sign of any oil. After 2h i had a black mixture with black solids at the bottom of the flask All was dissolved in 1l H2O and filtered, made basic with 10ml 50%NaOH and extracted with 200ml Chloroform. I got ~10ml of a orange waterlike solution, that i tested with the bisulfite method, no crystals formed. Maybe these 10ml were only water and dissolved iron or ironsalts,boh.

Did i use too much heat or isn't possible to reduce phenyl-2-nitropropene with Fe, HCl and H2O?
Any idea to reduce phenyl-2-nitropropene to P2P in a easy and secure way, maybe some ideas to improve my attempts?


 
Sonson
Junior Member   posted 06-04-98 07:05 AM          
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There is a slick way that use NaBH4/K2CO3/H2O2. I'm sure good 'ol Rhodium sits on the actual method for this procedure.
//Sonson


quirks
Member   posted 06-04-98 08:37 AM          
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Which phikal # does the nitropropene to ketone?
 
dreamer
Member   posted 06-04-98 01:01 PM          
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pihkal #98 for example
 
dreamer
Member   posted 06-04-98 01:01 PM          
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pihkal #98 for example
 
Rhodium
Administrator   posted 06-04-98 05:00 PM          
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16.3g (0.1 mole) phenyl-2-nitropropene was dissolved in 200ml methanol in a
250ml Erlenmeyer flask situated on a magnetic stirrer, and chilled to 0°C
with an ice/salt bath. Then, with good stirring, 7.6g (0.2 mole) of NaBH4
was added a little at the time, and the temperature was not allowed to to
rise above 15°C. When the generation of heat had subsided, the ice/salt-
bath was removed and the solution was stirred at room temperature for two
hours. At the end of this period, the flask was once again placed in an
ice/salt bath and the solution was allowed to cool to 0°C again. 100 ml of
30% H2O2 was then added, together with 30 grams of anhydrous potassium
carbonate, and the solution was left to stir for 18-24 hours at room temp.
During the addition of H2O2/K2CO3 a white, sticky precipitate forms, which
can be a bit too thick for a weak magnetic stirrer to handle, so the mass
can be stirred with a glass rod now and then during the first two hours,
after which the precipitate will be much looser and no match for any
mag-stirrer. The next day, the solution is slowly acidified with 2M HCl
with good stirring, care being taken for the evolution of heat and CO2.
About 300 ml of acid is needed. When the pH of the solution turned acid,
the color became significantly more yellow, but the acidity was confirmed
with pH paper. All of the precipitate was also be gone at this point. The
solution was extracted with 3x100ml CH2Cl2, and the pooled organic extracts
washed with 100ml 2M NaOH and 200ml H2O. The organic phase was dried over
MgSO4, filtered with suction, and the solvent removed under vacuum to give
a clear yellow oil. After distillation of said oil at aspirator vacuum, the
yield was around 60-70% of phenyl-2-propanone (P2P) as a light yellow oil.


Rhodium
Administrator   posted 06-04-98 05:00 PM          
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16.3g (0.1 mole) phenyl-2-nitropropene was dissolved in 200ml methanol in a
250ml Erlenmeyer flask situated on a magnetic stirrer, and chilled to 0°C
with an ice/salt bath. Then, with good stirring, 7.6g (0.2 mole) of NaBH4
was added a little at the time, and the temperature was not allowed to to
rise above 15°C. When the generation of heat had subsided, the ice/salt-
bath was removed and the solution was stirred at room temperature for two
hours. At the end of this period, the flask was once again placed in an
ice/salt bath and the solution was allowed to cool to 0°C again. 100 ml of
30% H2O2 was then added, together with 30 grams of anhydrous potassium
carbonate, and the solution was left to stir for 18-24 hours at room temp.
During the addition of H2O2/K2CO3 a white, sticky precipitate forms, which
can be a bit too thick for a weak magnetic stirrer to handle, so the mass
can be stirred with a glass rod now and then during the first two hours,
after which the precipitate will be much looser and no match for any
mag-stirrer. The next day, the solution is slowly acidified with 2M HCl
with good stirring, care being taken for the evolution of heat and CO2.
About 300 ml of acid is needed. When the pH of the solution turned acid,
the color became significantly more yellow, but the acidity was confirmed
with pH paper. All of the precipitate was also be gone at this point. The
solution was extracted with 3x100ml CH2Cl2, and the pooled organic extracts
washed with 100ml 2M NaOH and 200ml H2O. The organic phase was dried over
MgSO4, filtered with suction, and the solvent removed under vacuum to give
a clear yellow oil. After distillation of said oil at aspirator vacuum, the
yield was around 60-70% of phenyl-2-propanone (P2P) as a light yellow oil.


dreamer
Member   posted 06-05-98 02:47 PM          
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thanks!
 
dreamer
Member   posted 06-05-98 02:47 PM          
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thanks!
 
Labrat
Member   posted 06-08-98 04:46 AM          
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This is one weird synthesis: an reductant (sodium borohydride) AND an oxidant (hydrogen peroxide) are used in the same procedure. What is the meaning of this? Lr/
 
Labrat
Member   posted 06-08-98 04:46 AM          
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This is one weird synthesis: an reductant (sodium borohydride) AND an oxidant (hydrogen peroxide) are used in the same procedure. What is the meaning of this? Lr/
 
dreamer
Member   posted 06-08-98 01:51 PM          
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new dream with less heat:
0.6mol 32gr powdered Fe was heated in 140ml 96% technical acetic acid to 40°. On the first sign of bubbles i added 0.1mol 8gr phenyl-2-nitropropene in 150ml 96% acetic acid. The color changed to orange and then to deep red. The temperature never exceeded 60°!!.
White salts apeared on the bottom and a deep red layer at the top. Stirring was continued for 3h, then 1l of H2O was added, the mixture was filtered (to remove unreacted iron) and extracted with 200ml Ether.
The ether was eliminated under vacuum and i got 8.5ml of a orange - red oil, which was dissolved in a satured bisulfite solution. After 10 min the crystals separated out, which where filtered and putted in denatured alcohol. The crystals are still sitting in denatured alcohol, where the color of the crystals is changing from orange to white - yellow, maybe i can avoid a vacuum distillation.


dreamer
Member   posted 06-08-98 01:51 PM          
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new dream with less heat:
0.6mol 32gr powdered Fe was heated in 140ml 96% technical acetic acid to 40°. On the first sign of bubbles i added 0.1mol 8gr phenyl-2-nitropropene in 150ml 96% acetic acid. The color changed to orange and then to deep red. The temperature never exceeded 60°!!.
White salts apeared on the bottom and a deep red layer at the top. Stirring was continued for 3h, then 1l of H2O was added, the mixture was filtered (to remove unreacted iron) and extracted with 200ml Ether.
The ether was eliminated under vacuum and i got 8.5ml of a orange - red oil, which was dissolved in a satured bisulfite solution. After 10 min the crystals separated out, which where filtered and putted in denatured alcohol. The crystals are still sitting in denatured alcohol, where the color of the crystals is changing from orange to white - yellow, maybe i can avoid a vacuum distillation.


Rhodium
Administrator   posted 06-08-98 05:34 PM          
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Labrat: It is a one-pot two-step synthesis. First, NaBH4 reduces the nitroalkene to the nitroalkane, and then the H2O2/K2CO3 hydrolyzes the nitro group to a ketone. The last part is called "Nef reaction".
Ref: Synthesis, 723 (1994)


Rhodium
Administrator   posted 06-08-98 05:34 PM          
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Labrat: It is a one-pot two-step synthesis. First, NaBH4 reduces the nitroalkene to the nitroalkane, and then the H2O2/K2CO3 hydrolyzes the nitro group to a ketone. The last part is called "Nef reaction".
Ref: Synthesis, 723 (1994)


Labrat
Member   posted 06-09-98 09:37 AM          
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Now I understand! Thanx Rhodium, I'll check out the ref. Lr/
 
Labrat
Member   posted 06-09-98 09:37 AM          
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Now I understand! Thanx Rhodium, I'll check out the ref. Lr/
 
dreamer
Member   posted 06-12-98 01:46 PM          
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Rhodium plz answer
Does NaBH4 convert phenyl-2-nitropropene without catalyst to phenyl-2-nitropropane?
Does this also work for 1-(3,4-methylenedioxyphenyl)-2-nitropropene?

Is it also possible to make amphetamine from phenyl-2-nitropropane with Zinc/Hydrochloric Acid or does this only work with nitro terminated chains ?


 
dreamer
Member   posted 06-12-98 01:46 PM          
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Rhodium plz answer
Does NaBH4 convert phenyl-2-nitropropene without catalyst to phenyl-2-nitropropane?
Does this also work for 1-(3,4-methylenedioxyphenyl)-2-nitropropene?

Is it also possible to make amphetamine from phenyl-2-nitropropane with Zinc/Hydrochloric Acid or does this only work with nitro terminated chains ?


 
Rhodium
Administrator   posted 06-12-98 04:57 PM          
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Nitroalkenes are very easily reduced to the corresponding nitroalkanes, and this is true
for both phenylnitropropene and MDP-nitropropene. BUT - the method I posted above can NOT be used for production of MDP2P, as an intermediate is isomerized by the H2O2 to something unusable.
Here is two refs, nitroalkene to nitroalkane:

NaBH4 in methanol:
Synth Comm, 15(2), 151 (1985)

With baker's yeast (!!!):
Heterocycles, 37(1), 553 (1994)


 
Rhodium
Administrator   posted 06-12-98 04:57 PM          
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Nitroalkenes are very easily reduced to the corresponding nitroalkanes, and this is true
for both phenylnitropropene and MDP-nitropropene. BUT - the method I posted above can NOT be used for production of MDP2P, as an intermediate is isomerized by the H2O2 to something unusable.
Here is two refs, nitroalkene to nitroalkane:

NaBH4 in methanol:
Synth Comm, 15(2), 151 (1985)

With baker's yeast (!!!):
Heterocycles, 37(1), 553 (1994)


 
Sonson
Junior Member   posted 06-12-98 05:09 PM          
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Sad to say the yeast method isn't as versatile as others. But someone should try it out...The yield in this particular rxn is something like 50% with 1-nitro-2-phenylpropene as the substrate, but opposed to the borohydride reduction this gives only one enatiomer.
Bakers yeast also reduces esters, acids and ketones (1,2-diketones --> 1,2-diols 70% yield).


Sonson
Junior Member   posted 06-12-98 05:09 PM          
--------------------------------------------------------------------------------
Sad to say the yeast method isn't as versatile as others. But someone should try it out...The yield in this particular rxn is something like 50% with 1-nitro-2-phenylpropene as the substrate, but opposed to the borohydride reduction this gives only one enatiomer.
Bakers yeast also reduces esters, acids and ketones (1,2-diketones --> 1,2-diols 70% yield).


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