Síntese de 1-fenil-2-propanona (P2P) a partir de malonato de dietil(fenilacetil)malonato
- Thread starter G.Patton
- Start date
Refere-se a uma destilação simples em vez de uma destilação de vácuo? Pode, 216 graus Celsius é o ponto de ebulição em condições normais.
Pessoal, não caiam no culto do refluxo sagrado. O refluxo não tem qualquer valor em si mesmo, exceto a ilusão de que algo acontece, que ele cria.
Com o H2SO4 e o ácido oxálico (melhor), mas o ácido fosfórico e qualquer ácido orgânico, como o acético, fórmico ou cítrico, obtêm-se rendimentos quase quantitativos se a mistura for aquecida lentamente durante duas horas até NÃO MAIS de 95 °C, mantida durante 30 minutos e depois arrefecida. Adicionar uma pequena quantidade de solvente que não seja DCM (tolueno, xileno, éter), uma vez que o ácido orgânico pode cair, pelo que se aconselha a recolha a partir do topo. Pode ser utilizado éter de petróleo 40/60 e não é necessário muito, mas obtém-se TRÊS camadas no final: A camada superior é Pet-Ether com P2P dissolvido. A camada intermédia é P2P com Pet-Ether dissolvido*. E por baixo está a mistura ácida (que pode ser reutilizada sem problemas).
*Parece estranho, mas é assim que funciona: Tanto o Pet-Ether como o P2P dissolvem um pouco do outro, mas não são livremente miscíveis. E assim se obtêm as três camadas que já me deixaram quase louco há muito tempo. Até ter descoberto isto.......
200 g de ácido oxálico di-hidratado
300 ml de água
100 ml de H2SO4 37% (ácido de bateria)
nem todo o ácido oxálico se dissolve - não há problema
Com isto, é possível processar um mínimo de 200 ml de óleo vermelho 20230
É necessária uma agitação muito forte durante todo o tempo.
A mistura água/ácido pode ser reutilizada.
A temperatura não superior a 95 °C permite obter P2P amarelo claro diretamente sem vapor ou outra destilação.
Quando se usa um funil de separação, é melhor separar enquanto ainda estiver quente e o oxálico não cair, ou colocá-lo num copo no congelador com o fundo do copo a tocar no frio, para que comece a cristalizar a partir daí. Se fizer isto não precisa de solvente, o ácido e a água que se cristalizam a partir do fundo conduzirão o P2P para o topo e pode simplesmente despejá-lo ao fim de duas ou três horas e NADA de P2P ficará para trás.
Tive muito trabalho neste caso, lol
Com o H2SO4 e o ácido oxálico (melhor), mas o ácido fosfórico e qualquer ácido orgânico, como o acético, fórmico ou cítrico, obtêm-se rendimentos quase quantitativos se a mistura for aquecida lentamente durante duas horas até NÃO MAIS de 95 °C, mantida durante 30 minutos e depois arrefecida. Adicionar uma pequena quantidade de solvente que não seja DCM (tolueno, xileno, éter), uma vez que o ácido orgânico pode cair, pelo que se aconselha a recolha a partir do topo. Pode ser utilizado éter de petróleo 40/60 e não é necessário muito, mas obtém-se TRÊS camadas no final: A camada superior é Pet-Ether com P2P dissolvido. A camada intermédia é P2P com Pet-Ether dissolvido*. E por baixo está a mistura ácida (que pode ser reutilizada sem problemas).
*Parece estranho, mas é assim que funciona: Tanto o Pet-Ether como o P2P dissolvem um pouco do outro, mas não são livremente miscíveis. E assim se obtêm as três camadas que já me deixaram quase louco há muito tempo. Até ter descoberto isto.......
200 g de ácido oxálico di-hidratado
300 ml de água
100 ml de H2SO4 37% (ácido de bateria)
nem todo o ácido oxálico se dissolve - não há problema
Com isto, é possível processar um mínimo de 200 ml de óleo vermelho 20230
É necessária uma agitação muito forte durante todo o tempo.
A mistura água/ácido pode ser reutilizada.
A temperatura não superior a 95 °C permite obter P2P amarelo claro diretamente sem vapor ou outra destilação.
Quando se usa um funil de separação, é melhor separar enquanto ainda estiver quente e o oxálico não cair, ou colocá-lo num copo no congelador com o fundo do copo a tocar no frio, para que comece a cristalizar a partir daí. Se fizer isto não precisa de solvente, o ácido e a água que se cristalizam a partir do fundo conduzirão o P2P para o topo e pode simplesmente despejá-lo ao fim de duas ou três horas e NADA de P2P ficará para trás.
Tive muito trabalho neste caso, lol
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- By w2x3f5
indique o rendimento da substância p2p, por favor.
tem óleo vermelho? estranhamente, eu tinha óleo amarelo com o mesmo número.
tem óleo vermelho? estranhamente, eu tinha óleo amarelo com o mesmo número.
Is there any other way to isolate the phenylacetic acid besides putting it in the refrigerator? Will not separating affect my future work?
- By William D.
You can crystallize this in a cool place and filter after. In another case, you can distill the fractions. For the following steps, you cannot leave PPA.
I would like to know if this synthesis is also working with phosphoric acid ( h3pO4) I appreciate your work and time
And what would be the amount ( phosphoric acid 85%)
Currently performing a test on the substrate with 75% phosphoric acid. No exact amounts used.
Trying with about 1:2 (Precursor to Phosphoric acid), again no exact amounts used but will report back if it works at all.
Trying with about 1:2 (Precursor to Phosphoric acid), again no exact amounts used but will report back if it works at all.
Tests using 75% phosphoric acid 1:2 (substrate to acid). 1 hour and 30 minutes into the reaction. Took a small "sniff test" and I seem to be able to detect the distinct odour of phenyl-2-propanone.
Lots of bubbling in the reaction that started as early as 60 degress celcius.
Again no exact amounts was actually used as the substrate I tried was a sample purchase from a chinese vendor (not on this site). Red liquid just like the photos of the malonate everywhere, the smell was not super pleasant but not horrible. Around 100 euro per kilo (actually less considering shipping was included)
Lots of bubbling in the reaction that started as early as 60 degress celcius.
Again no exact amounts was actually used as the substrate I tried was a sample purchase from a chinese vendor (not on this site). Red liquid just like the photos of the malonate everywhere, the smell was not super pleasant but not horrible. Around 100 euro per kilo (actually less considering shipping was included)
2 hours and 23 minutes into the reaction and I can confirm 100% that 75% phosphoric acid definitely works. However the reaction is still bubbling from CO2 evolution, so the reaction is not done.
The smell of phenyl-2-propanone is now too strong to dispute. The substrate was legit.
Further experimentation needs to be done to determine optimal amount of phosphoric acid.
Previous experience: [P2NP (from benzaldehyde & nitroethane) to phenyl-2-propanone with iron powder and HCL] and [MAPA to phenyl-2-propanone with hydrochloric acid])
If I remember correctly the p2np to phenyl-2-propanone with iron powder and HCL sometimes produced phenyl-2-propanone with an acrid smell. however the smell of the phenyl-2-propanone from the malonate is extremely sweet and that of pure phenyl-2-propanone.
Will store the resulting phenyl-2-propanone as a powder by reacting it with metabisulfite.
edit: Also beware of alibaba sellers of BMK precursors, one of them was not legit. (check the bot reviews, the fake sellers strictly sell precursors and have fake reviews of GBL and synthetic cannabinoid indole derivatives)
The smell of phenyl-2-propanone is now too strong to dispute. The substrate was legit.
Further experimentation needs to be done to determine optimal amount of phosphoric acid.
Previous experience: [P2NP (from benzaldehyde & nitroethane) to phenyl-2-propanone with iron powder and HCL] and [MAPA to phenyl-2-propanone with hydrochloric acid])
If I remember correctly the p2np to phenyl-2-propanone with iron powder and HCL sometimes produced phenyl-2-propanone with an acrid smell. however the smell of the phenyl-2-propanone from the malonate is extremely sweet and that of pure phenyl-2-propanone.
Will store the resulting phenyl-2-propanone as a powder by reacting it with metabisulfite.
edit: Also beware of alibaba sellers of BMK precursors, one of them was not legit. (check the bot reviews, the fake sellers strictly sell precursors and have fake reviews of GBL and synthetic cannabinoid indole derivatives)
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Appreciate your work hope we can get a detailed syntheses of phosphoric acid. I have 85% of phosphoric acid and hope to find a way that is working
Take notice: Ignore the 5 hour bullshit, it was not enough for me with 75% phosphoric acid. I ended up with way too much oil than theoretically possible. i.e. it was a mixture of the precursor and product, the precursor had not fully reacted. (I also detected the precursor smell when working up the reaction). This is a big problem according to me as they are annoying to separate from eachother. Therefor it is important, imo, to run the reaction to completion, I'd rather have bi-products or some slight polymerisation from running the reaction longer than unreacted precursor.
Better to end the reaction when it no longer is bubbling or bubbling very little.
Also don't wait for a detailed guide. Just try it yourself using small amounts.
Either use a 1:1 or 1:2 ratio of precursor to phosphoric acid. This is not that complex.
Better to end the reaction when it no longer is bubbling or bubbling very little.
Also don't wait for a detailed guide. Just try it yourself using small amounts.
Either use a 1:1 or 1:2 ratio of precursor to phosphoric acid. This is not that complex.
May I ask which solvent can be used instead of ether?
Use any compatible solvent, Such as DCM, MTBE etc etc.
The solvent needs to follow 2 criteria,
* Should not be too easy to hydrolyse (e.g. ethyl acetate hydrolyses in basic conditions, so if used you have to minimize it by either low % NaOH solution or be fast)
* Needs to be non polar and not misicible/soluble in water.
Preferably low boiling point so it can be removed easy later, but if that is not a concern for you
you also got things like toluene
I currently use an ether but not diethyl.
The solvent needs to follow 2 criteria,
* Should not be too easy to hydrolyse (e.g. ethyl acetate hydrolyses in basic conditions, so if used you have to minimize it by either low % NaOH solution or be fast)
* Needs to be non polar and not misicible/soluble in water.
Preferably low boiling point so it can be removed easy later, but if that is not a concern for you
you also got things like toluene
I currently use an ether but not diethyl.
↑View previous replies…
May I ask if I can still succeed by adding 20% alkaline solution after heating and refluxing, but the pH value can only reach 7?
Sorry you have to be clearer in your writing mate.
An alkaline solution can never be below 7, alkaline is just chemistry speech for "basic" (i.e. above 7 on the pH scale)
Why is it important for you too not go below 7? (or above 7)?
Please tell me which reaction and chemicals you intend or are currently using. You doing the sulfuric acid variant, phosphoric acid or saponification + hydrochloric acid variant?
An alkaline solution can never be below 7, alkaline is just chemistry speech for "basic" (i.e. above 7 on the pH scale)
Why is it important for you too not go below 7? (or above 7)?
Please tell me which reaction and chemicals you intend or are currently using. You doing the sulfuric acid variant, phosphoric acid or saponification + hydrochloric acid variant?
Heating reflux for 5 hours, adding 20% sodium hydroxide solution to the ice bath, the pH value is stuck at 7
Assume you meant you added the alkaline to the reaction mixture while it's in a ice bath. Anyway if the pH value is stuck at 7, your pH meter or pH paper doesn't work correctly. What are you using to measure the pH?
And what acid did you use?
Edit:
The first guy who replied to this thread said the following (note the pH thing with the saponification or whatever)
"Perform CAS 20320-59-6 official procedure After 4 hours of reaction at 80°C, stop heating, then adjust the alkali pH with sodium hydroxide, until 7, it can't go up, stratification appears, the oil layer is on top, and then ether extraction is added, and the stratification begins, and the ether layer is extracted, and the upper layer starts, and the distillation at atmospheric pressure at 220° keeps going up, and the temperature keeps it at 110°, and a lot of liquid is distilled, and I think it's ether, and then it starts to appear, and this phenomenon in the flask I thought it would be 216° distillation to produce P2P, but there is no problem How can I remedy it "
And what acid did you use?
Edit:
The first guy who replied to this thread said the following (note the pH thing with the saponification or whatever)
"Perform CAS 20320-59-6 official procedure After 4 hours of reaction at 80°C, stop heating, then adjust the alkali pH with sodium hydroxide, until 7, it can't go up, stratification appears, the oil layer is on top, and then ether extraction is added, and the stratification begins, and the ether layer is extracted, and the upper layer starts, and the distillation at atmospheric pressure at 220° keeps going up, and the temperature keeps it at 110°, and a lot of liquid is distilled, and I think it's ether, and then it starts to appear, and this phenomenon in the flask I thought it would be 216° distillation to produce P2P, but there is no problem How can I remedy it "
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