raffike (Hive Addict)
12-11-02 10:24
No 388453
      P2NP to P2P rx vessel     

Ok,raf got some benzaldehyde and probably will get some nitroethane soon.But there lies that problem with P2NP to P2P reduction step,it needs good vessel so raf thought,since SS rusts,he could make copper vessel for that purpouse.Copper should handle HCl acid just fine.Or is there any reason one should not make it from copper?Raf has 5 liters of benzaldehyde and it makes about 6 kgs of P2NP and 50 liter vessel should be ok.Raf has few questions more so if anyone is familiar with that method,it would be nice if he replied.
PS. i made 30000'th post to stimu forumsmile

For those about to synth,we salute you
(Chief Bee)
12-11-02 10:38
No 388459
      Copper is not compatible with concentrated HCl, I ...     

Copper is not compatible with concentrated HCl, I would really like to suggest that you perform the conversion in several smaller batches using normal glass, or that you use stainless steel and the Iron/Acetic Acid reduction instead.

6kg of P2NP from 5L benzaldehyde was pretty optimistic, how are you planning to perform this condensation? When you have so much starting material to convert, could you do the Hive collective a big favor and perform the condensation in several smaller batches varying the reaction conditions, so that you can help develop an optimized procedure? If you are interested, PM me and I'll give you a set of suggested variations.

How are you planning to isolate the product afterwards? Solvent extraction or steam distillation? At the scale you are suggesting, whatever you choose will involve an incredible amount of work.

Terbium is the person you'd want to consult in this matter though.
(Hive Addict)
12-11-02 10:50
No 388465
      I've read many posts and hardest chemical for me ...     

I've read many posts and hardest chemical for me to acquire would be that catalytic iron powder(laughs please).Steam distillation seems to be less messy than solvent xtraction but lots of electricity will be wasted to generate these big amounts of steam,although one could use propane for heating.Haven't found any nitroethane yet but it will be no problem for raf.Benzaldehyde will be converted to P2NP with cyclohexylamine.That's 20 bucks a litre from Fluka and it'll be enough for 4-5 kg's BzCHO.One could also electro-reduce P2NP to amph and it might be better way than via P2P.And there's also LAH reduction.I'll gladly help ya if i can.

For those about to synth,we salute you
(Chief Bee)
12-11-02 18:30
No 388603
      You don't need to generate external steam to be ...     

You don't need to generate external steam to be able to perform a steam distillation, just dilute the organic phase with twice its volume of water, and then distill as usual. For every gram of P2P distilling over, 10 grams of water will co-distill, so use a sepfunnel as a recieving flask, and periodically return the water to the distilling flask.
(Hive Addict)
12-12-02 05:34
No 388758
      Ah in that case steam is way to go.     

Ah in that case steam is way to go.Sent you a pm already.Raf has some 12 liter roundbottoms so rx vessel will be no problem.Now he he orders some cyclohexylamine.Rhodium i'll send you a pm when cyclo arrives.

For those about to synth,we salute you
(Wizard Master)
12-12-02 17:05
No 388953
      raffike: Read the procedure below BEFORE you ...     

raffike: Read the procedure below BEFORE you start. Just use 5 moles of nitroethane. I would suggest to do a small-scale run first.

12-13-02 01:54
No 389063
      Wiz you mention nitroethane and yet the link says ...     

Wiz you mention nitroethane and yet the link says nitromethane in the synthesis? Just curious is all.

Raffike If you get hold of nitroethane, combining it with your benzaldehyde and a little dry ammonium acetate and then gently reflux for 5 or 6 hours and you have a simple high yielding route to P2NP that never fails despite my ever changing reaction specifics. (that's chemspeak for haven't got a fucking clue!)
The crude product once recrystalised from hot MeOH is beautiful pale yellow needles all about an inch in length that are so nice that they no longer have any effect on your eyes or sinuses....................ok, that's complete bullshit but they are pretty! 

Regards, Hematite.
(Hive Addict)
12-13-02 07:54
No 389113
      No nitroethane needed?     

No nitroethane needed?Nitromethane is common model racing fuel over here.Wow,WizardX you are the best.I'll dive deeper into that procedure.Thanks
That ammonium acetate procedure seems ok too since i could get hold of ammonium acetate easily.
EDIT:But styrene yields phenylethylamine when reduced,that makes it little harder overall.I see if i can get nitroethane and what were the yields when ammonium acetate was used?

For those about to synth,we salute you
(Chief Bee)
12-13-02 09:06
No 389120
      WizardX probably mean that you should use the ...     

WizardX probably mean that you should use the OrganicSynthesis procedure, but instead of the nitromethane use nitroethane, to produce phenyl-2-nitropropene instead of nitrostyrene.
(Hive Addict)
12-13-02 09:10
No 389123
      ah,why didn't i figure it out myself.     

ah,why didn't i figure it out myself.Thanks rhodium

For those about to synth,we salute you
(Stoni's sexual toy)
12-14-02 08:43
No 389455

I love it when people acquire a certain amount of a chemical and then wonder how to convert that stuff into something usefull all at once!

What if the reaction they intend to use fails?
What if the reaction they intend to do only runs in smaller amounts?
What if the writeup is incomplete, missing a few small but crucial details?
What if the workup will be very difficult?
What if the cook fucks up? Or a flask drops? Shit happens all the time.

It is usual to read stuff like "... extracting the product with DCM, washing the combined extracts twice with NaHCO3 followed by H2O, evaporating the solvent to yield crude product (VII)..." in chemistry journals. What that sentence doesn't tell you is that it might have taken the researchers a full day to perform this step on a small scale, and it will take you several days to do it big scale. Now imagine your product being somewhat sensitive and not handling the conditions it is under very well. Can you imagine the unexpected yield reduction when it will take you three days to do it?
Been there done that, and it sucks!

That's why I say plan your synth carefully, start small and work your way up slowly and deal with the problems as they arise. Only a fool would bet all his money, belongings, wife and children's destiny on a race horse he doesn't know.

I'm not fat just horizontally disproportionate.
(Hive Addict)
12-14-02 09:36
No 389470
      Raf's planning to run synth described in Louis ...     

Raf's planning to run synth described in Louis Freeh large scale benzaldehyde to meth story,just cyclohexylamine is used not n-butylamine.Freeh describes how to construct large vessel for Fe/HCl reduction too.Raf has some big glassware so he doesn't need to construct anything.Benzaldehyde to P2NP with cyclohexylamine is described in
Scale-up should be no-problem.

For those about to synth,we salute you
(Chief Bee)
12-14-02 13:09
No 389520
      Louis Freeh is an FBI director, and I don't find ...     

Louis Freeh is an FBI director, and I don't find that alias in the user database. Could you point me towards the story you mention?

Just a cautonary note: While you may be able to synth phenyl-2-nitropropene on a large scale by just scaling up a lab procedure, the same is not true with the iron reduction to P2P. Try it using as little as 100g P2NP first and you know why it isn't fun to do on a multi-kg scale.
(Hive Addict)
12-14-02 13:14
No 389522
      That procedure is on your website.     

That procedure is on your website.In that zip file,4-th doc.

For those about to synth,we salute you
12-14-02 18:43
No 389562
      Yield from the benz/nitro/ammonium acetate synth ...     

Yield from the benz/nitro/ammonium acetate synth are extremly high and consistantly easy to obtain, never calculated it precisely however.
Rhodium is very correct in advising small beginnings with the iron/acetic acid stage to P2P, it has humble beginnings that quickly turn into a volumous messy shitfight of a workup sometimes and on a larger scale than I had expected, too big would really suck if one wasn't anticipating the necessary requirements, good luck.

Regards, Hematite.
(Hive Addict)
12-14-02 23:52
No 389589
      Iron/acetic acid is very volume inefficient ...     

Iron/acetic acid is very volume inefficient procedure.If one had 4 or 5 kgs of P2NP,he would need copious amounts of GAA.Fe/HCl seems to be the best way.There's some procedure with cromium(II)chloride too but that isn't tested yet.

For those about to synth,we salute you
(Chief Bee)
12-15-02 00:49
No 389597
      You'll notice...     

It is not so much the GAA being the problem, more that you will have to dilute the post-reaction mixture so much after the neutralization to be able to do anything useful with it (regardless of choice of acid), the precipitated iron salts are extremely voluminous and gel-like.
(Hive Addict)
12-15-02 00:55
No 389600
      Yeah,it needs lots more iron than HCl method.     

Yeah,it needs lots more iron than HCl method.Ammonium acetate is a chemical i can get easily(reagent grade),just substitute cyclohexylamine with AmAc.Raf's probably going to some test runs soon,like 100 grams of benzaldehyde,80 grams of nitroethane and 20 grams of ammonium acetate and see what comes out.

For those about to synth,we salute you
(Hive Bee)
12-15-02 03:25
No 389627
      Test it first     

on a small scale. If you have done it on a 10 mmol or a 100 mmol scale increase it to a 1 mol scale before you jump up to a 10 - 50 mol scale. Very strange things might happen when things are scaled up. This is the difference between research chemistry and production chemistry. Let me tell you that there is a huge difference between them.

Research chemistry never takes into consideration the necessary parameters for large-scale production. It is very common to find something new and interesting in the litterature but it is impossible to produce anything profitable from that description. So in order to go into production everything or close to everything has to be done from scratch again.

Researchers very often use Pt- or Pd black for catalytic hydrogenations. Production plants never ever use those catalysts. They are way too expensive. Ok, there might be a few exceptions to what Ive just said. But those exceptions are always when there is no other catalysts which works and the product is like 50 times more expensive than gold.

What about GAA/Fe or HCl/Fe reductins then? Well some factories actually still use HCl/Fe for large-scale reductions of various aromatic nitro compounds. But those factories are always located somewhere where electricity is cheap because steam distillaton is the only way to separate the product from the nasty iron sludge.

Catalytic hydrogenation freak
(Hive Bee)
12-15-02 04:17
No 389629
      PNP and P2P
(Rated as: excellent)

Nitro alkene derivatives
H.B. Hass, A.G. Susie, R.L. Heider
J.Org. Chem. Vol 15, pp. 8-14 (1950) (../rhodium/pdf /nitrostyrenes.fe-hcl.pdf)


One mol each of benzaldehyde and nitroethane, 5 ml n-butylamine and 100 ml EtOH were refluxed for 8 hours in a 1000 ml rb-flask. When the contents were cooled and stirred a heavy yellow crystalline mass formed immediately. After recrystallization from absolute EtOH the product weighed 105 g (conversion 64% of theory, yield 86,5%) with a m.p. of 65C.


One-tenth of a mole of nitroalkene, 0,72 gram atom (40 g) of 40 mesh cast iron turnings, 75 - 100 ml of distilled water and 0,1 g of ferric chloride were placed in a 500 ml rb-three-neck flask equipped with a graduated dropping funnel, a mercury-seal stirrer and a reflux condenser. Fifteen ml of conc. HCl was added dropwise over 5-6 hours and the temperature of the surrounding oil-bath maintained between 85 - 95C. The mixture was then basified with 25% aq NaOH and steam distilled. the distillate was extracted several times with ether, the ether distilled and the residue rectified through a Podbielniak column at reduced pressure.

--------Molar ratio--------ml/mole alkene--------Product--------
--Fe/alkene--HCl/alkene----Water--Solvent------P2P--P2p oxime---

---2---------0-------------500-----0----------0%------ 20,1%-----

(a)- MeOH
(b)- Benzene
(c)- EtOH

Catalytic hydrogenation freak
(Hive Addict)
12-15-02 05:42
No 389644
      Thanks for tables,raf will start small.     

Thanks for tables,raf will start small.Freeh procedure uses 3,5 mole Fe per mole of alkene and 7 mole of HCl and he says yields are close to 75%.He uses only water as solvent.Raf thinks Freeh might be right and follows his advice.Small reaction shows all.

For those about to synth,we salute you
(Wizard Master)
12-17-02 17:19
No 390369
      Use a deanstark water trap     

Use a deanstark water trap to improve the synthesis yield of 1-Phenyl-2-nitropropene.

I would also suggest, NOT to waste your time in converting 1-Phenyl-2-nitropropene to 1-Phenyl-2-propanone, but reduce the 1-Phenyl-2-nitropropene directly to amphetamine.
12-25-02 14:12
No 392807
      See: us 2233823 : and Alles , Am Soc, 54, 271 ...     


Patent US2233823:

and Alles , Am  Soc, 54, 271, 1932

06-02-03 12:28
No 437281
      what is the name of the compound that results...     

what is the name of the compound that results from the
 knoevenagel condensation of nitroethane and benzaldehyde using
MeOH and NaOH rather than an amine as catalyst - is it phenyl-2-nitropropan-1-ol?
i understand that this condensation works since phenylpropanolamine can be
prepared this way .

phcho + etNo2 (MeOH/NaOH) --> phenyl-2-nitropropan-1-ol
reduce the nitro to get ppa.

But what about hydrolysising(sp) the alcohol to the the olefin.

phenyl-2-nitropropan-1-ol + Hcl(hydrolysis) --> phenyl-2-nitropropene

Are there any refs to back up this hydrolysis of the alcohol
to the olefin. it works with the derivative of phcho and MeNo2 (NaOH/MeOH)
but here your dealing with the condensation of phcho and EtNo2.

some girls are bigger than others
(Chief Bee)
06-08-03 12:14
No 438686
      Gordon Alles: DL-beta-Phenylsopropylamines     

The ref posted by roger2003 above can be found at my page:

Gordon Alles
J. Am. Chem. Soc. 54, 271 (1932) (../rhodium/chemistry /meth.alles.html)
(Active Asperger Archivist)
07-14-03 14:03
No 447210
      US Pat 2233823 Red of Arylnitroalkenes
(Rated as: good read)

US Patent 2233823

Process for the Reduction of Arylnitroalkenes


This article outlines a method for the catalytic reduction of nitropropenes, such as phenylnitropropene to Benzedrine, without the formation of high-molecular weight polymers or low yields.  The nitropropene is effectively converted to its oxime for further reduction using finely divided iron metal in the presence of water, but NO acid.  (If acid is present, the ketone is the predominant product.)  Further reduction is conveniently carried out using a variety of possible reductions.

Example 1:

1-phenyl-2-nitropropene was dissolved in water, organic solvent or aqueous organic solvent.  Forty mesh iron filings were added and in some cases acid and/or ferric chloride was incorporated into the mixture.  The molar quantities of solvent, iron, acid, and catalyst/mol of nitropropene for the various reductions are shown in Table I.  In each case, the mixture was agitated for a period of approximately 5.5 hours in a vessel equipped with a reflux condensor.  At the conclusion of this period, the mixture was made alkaline with sodium hydroxide solution and steam distilled.  The products were recovered from the steam distillate, dried and carefully fractionated in a rectifying column to determine the yield of phenylpropanone and of the oxime of phenylpropanone.   In the second stage of our reduction process the oxime obtained in the first stage is further reduced to the amine.  Any suitable means for reducing the oxime may be used.  Among these methods may be mentioned reduction with sodium amalgam and acetic acid, reduction with metallic sodium in alcoholic solution, and hydrogenation with a platinum, palladium or nickel catalyst.  We prefer to employ hydrogenation with a nickel catalyst, and this process in illustrated in Example 2.

Example 2:

Approximately 9 parts of the oxime of phenylpropanone was dissolved in approximately 60 parts of 95% ethanol, containing 5 parts of a nickel catalyst, prepared by dissolving aluminum from a nickel aluminum alloy by means of caustic alkali.  The resulting mixture was sealed in a bomb under a hydrogen pressure of 1880 psi and reduction was effected for a period of 3.5 hours at a temperature of 25*C at the conclusion of which period the pressure was found to have dropped to approximately 1680 psi.  The pressure was then released and the catalyst removed by filtration.  The filtrate was acidified with conc. HCl acid and the product was recovered by crystallization as the HCl salt of 1-phenyl-2-aminopropane (MP: 144-146*C).  A conversion of 78% based on original oxime was obtained.

Mols water Mols org. solvent Mols FeCl3 Mols Fe Mols Acid Oxime Yield Ketone Yield
28 0 0 0 2 0 0
28 0 0.06 2 0 20.1 0
28 0 0 2 (1) 0.06 49 5.2
28 0 0.06 2 (1) 0.06 45 3.7
28 0 0 2 (1) 0.23 27.4 24.6
28 0 0 2 (1) 0.46 23.1 36.5
28 0 0.06 2 (1) 1.39 20.2 41.1
28 0 0.06 2 (1) 1.74 13.4 56
28 0 0.06 7.15 (1) 1.74 0 75
28 0 0.06 7.15 (1) 1.97 0 77
28 0 0 2 (3) 0.1 32.5 11.3
28 0 0 2 (3) 0.52 37.5 10.5
0 (4) 12.4 0.06 2 (1) 0.06 0 0
14 (4) 12.4 0.06 2 (1) 0.06 62.6 10.5
14 (5) 4.4 0.06 2 (1) 0.06 64.2 9.9
14 (5) 8.9 0.06 2 (1) 0.06 63 9.7

(1) HCl
(2) Sulfuric
(3) Acetic
(4) Methanol
(5) Ethanol

Act quickly or not at all.
02-24-04 14:03
No 490866
      ...and nitroethane containing ethylformate?     

Does anyone know if ethylformate impurities will interfere with the reaction

C6H5-CHO + C2H5NO2 + R-NH2 -> C6H5CH=C(CH3)NO2 + R-NH2 + H2O

Or if it could perhaps be even used as solvent? The reason why I'm asking is that SWIM has a LOT of ethyl formate, but unfortunately his nitroethane seems to contain about 10-20% by volume of this stuff (don't ask), a molar exact 1:1 ratio of benzaldehyde and his "nitroethane" with ammonium acetate as catalyst produced only 40% of the theoretical possible P2NP, but the washing water smelled heavily from benzaldehyde; SWIM is very upset now, as although rxn conditions were not anhydrous at all (SWIM ran out of silica gel..), he should have got more than 40%!! He doesn't know whether his bad yield is due to the ethyl formate interfering with the above reaction or if he just has to multiply the amount of his "nitroethane" by 1.2 to compensate for the ethyl formate present bcuz it doesn't do anything besides of diluting the rxn, serving as a solvent? Hm, that would bee easy..smile

Or does he have to perform a fractional distillation bcuz ethyl formate does matter in some way?mad

(Wizard Master)
02-24-04 16:28
No 490895

ethyl formate, CH3CH2OC(=O)H can condense with benzaldehyde.

C6H5-CHO + 2 CH3CH2OC(=O)H ==> C6H5-CH(-O-CH2CH3)2  aldehyde acetal

Tech grade ethyl formate will contain ethyl orthoformate and this will react with aldehydes to produce aldehyde acetal.

-Bromocinnamic aldehyde acetal. In a 250-ml. flask are placed 45 g. (0.21 mole) of -bromocinnamic aldehyde, 50 ml. (0.3 mole) of ethyl orthoformate, 40 ml. of absolute ethanol, and 0.5 g. of ammonium chloride.

Technical ethyl formate was purified by washing with 3 per cent sodium carbonate solution, then with cold water, drying over anhydrous sodium sulfate, filtering, and fractionating. Compare p. 180. It is very important that all the materials used in the synthesis of acetol be anhydrous, as otherwise condensation products are formed.
02-24-04 17:43
No 490907
      ethyl formate     

First, thanks for your information, WizardX, most informative!

Too bad, obviously the condensation happening between aldehydes and ethyl formate results in an unwanted side product. And after I told him SWIM is almost sure his bad yield was a result of acetal byproduct formation, too. Do you know which properties benzoic aldehyde acetal has, especially solubility/suitable solvents, boiling point? And what does it smell like? Almonds I guess?
(That would explain the smell after SWIM washed his post rxn mixture, if the acetal is water soluble this would bee a simple explanation)
The reason why I asked about ethyl formate was because SWIM wants to purify his nitroethane by removal of the ethyl formate with which it is "contaminated". Although the orgsyn procedure for purification of ethyl formate could bee very useful in case SWIM would need his large amount of ethyl formate for some wierd synth (this will happen for sure sooner or later, any suggestions for its use?), SWIM just wants to clean the formate out of his precious NE without fract. distillation because his vigreux column broke a while ago...frown and he is planning on condensing NE with BA, not BA with formate..tongue

Any suggestions are welcome!

Oh, I forgot: does anyone know if ethyl formate will form an azeotrope with nitroethane when distilling? (if this was NOT the case, a careful simple distillation would do the trick, SWIM would love to hear that!)laugh
03-09-04 11:27
No 493998
      from benzaldehyde to p2p one pot     

Did anyone ever take a look at Patent US2557051, "Preparation of alkyl-aralkyl-ketones", Richard V. Heinzelmann, April 1948?

The clue here is the condensation of aromatic aldehyde with aliphatic nitroolefins (they do it explicitly with benzaldehyde and nitroethane), followed by reduction to the corresponding ketones (phenylacetone in our case, look at the topicwink) with iron/aequous HCl WITHOUT isolating the nitroparaffin (P2NP..) - which means IN THE SAME REACTION VESSEL!!
He too had to steam distill the ketone, collecting rather large amounts of distillate, but that's the disadvantage of the Fe/HCl method in general, right?

Anyway, perfoming the benzaldehyde/nitroethane condensation with butylamine in toluene and then reducing the nitropropene to p2p by adding water and iron to the henry-condensation postrxn mixture and dripping HCl into it, steam distill, separate and, voil: ketone, yield is claimed 75% of theory (calculated from starting mat. BA) ... seems to bee less time consuming than to separate and reXtalize P2NP! laugh

Greets A

(sorry, I know the last post was a bit off topic but funny, but this one's better, isn't it?)
03-17-04 08:13
No 495735
      ethyl orthoformate impurities     

..well, tech grade ethyl formate MAY contain some ethyl orthoformate (which can form condensation products with benzaldehyde), but this can be easily avoided if ethyl formate is distilled prior to use:

Ethyl formate: bp765 53-54C
Ethyl orthoformate (orthoformic acid triethyl ester): bp765 143C

...sez MERCK!
And my organic textbook tells me that if liquids have boiling points with a difference of more than 30, they can be easily separated by simple distillation (column is only needed if bp difference is less than 30C, -> azeotropic distillation) So, I understand I could clean ethyl formate by distilling it (assumed ethyl orthoformate was the main impurity), washing may be inadequate here.

(just for correctness and completeness)smile