P2NP to P2P rx vessel

[raffike]

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

[WizardX]

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.

[roger2003]

See:

Patent US2233823

:

and Alles , Am  Soc, 54, 271, 1932



roger2003

[algebra]

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 .

eg
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.
eg

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)
 

http://www.orgsyn.org/orgsyn/prep.asp?prep=cv1p0413

but here your dealing with the condensation of phcho and EtNo2.

[Rhodium]

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

DL-Beta-Phenylsopropylamines
Gordon Alles

J. Am. Chem. Soc. 54, 271 (1932)

(https://www.thevespiary.org/rhodium/Rhodium/chemistry/meth.alles.html)

[armageddon]

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..

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

THX!

[WizardX]

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.

http://www.orgsyn.org/orgsyn/prep.asp?prep=cv3p0731

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

http://www.orgsyn.org/orgsyn/prep.asp?prep=cv2p0005

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.

[armageddon]

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...  and he is planning on condensing NE with BA, not BA with formate..

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!)

[armageddon]

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 topic ) 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, voilà: ketone, yield is claimed 75% of theory (calculated from starting mat. BA) ... seems to bee less time consuming than to separate and reXtalize P2NP!  

Greets A

(sorry, I know the last post was a bit off topic but funny, but this one's better, isn't it?)

[armageddon]

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

...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 30°C, -> 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)

A