1-Phenyl-2-propanone (P2P) synthesis from Diethyl(phenylacetyl)malonate

[w2x3f5]

This reaction also goes with phosphoric acid

 

[LordCrackingtonson]

This reaction also goes with phosphoric acid

w2x3f5The original synthesis on page 1 calls for 7.5ml concentrated sulphuric acid.

If you substitute 85% phosphoric acid instead, how much would be required?

 

[w2x3f5]

The original synthesis on page 1 calls for 7.5ml concentrated sulphuric acid.

If you substitute 85% phosphoric acid instead, how much would be required?

View attachment 13655

LordCrackingtonsonI did several times, mixed the oil 1 to 1 with phosphoric acid, heated it until the gas evolution stopped. Unfortunately, I did only a few hydrolysis and did not record.

 

[LordCrackingtonson]

I did several times, mixed the oil 1 to 1 with phosphoric acid, heated it until the gas evolution stopped. Unfortunately, I did only a few hydrolysis and did not record.

w2x3f5Did you use glacial acetic acid and phosphoric acid together.. or just equal amounts phenylacetylemalonate and phosphoric acid?

 

[w2x3f5]

Did you use glacial acetic acid and phosphoric acid together.. or just equal amounts phenylacetylemalonate and phosphoric acid?

LordCrackingtonsonH3PO4 only

 

[41Dxflatline]

Some bees buzzed that diethyl(phenylacetyl)malonate could be used directly in a Leuckart reduction without first being converted to P2P

 

[w2x3f5]

Some bees buzzed that diethyl(phenylacetyl)malonate could be used directly in a Leuckart reduction without first being converted to P2P

41Dxflatlineduring the hydrolysis of malonate, impurities in the ketone, the color of the ketone is more dirty than with glycidate

 

[w2x3f5]

Never used it, they mentioned it in passing on the vespiary as possible but none of them seemed to have actually tried it

41DxflatlineI use with H3PO4 hydrolysis, but one or two times

 

[Monstapoint]

Introduction​

This is one of the simplest ways to obtain 1-Phenyl-2-propanone (P2P). Diethyl(phenylacetyl)malonate can be bought in some web market quite easy or synthesized by yourself using this method. Also, you can learn other P2P synthetic paths in our forum by following links: Synthesis of P2P from benzaldehyde with MEK, Synthesis of P2P by oxidation of alpha-methylstyrene with Oxone, Phenylacetone (P2P) syntheses via Grignard reagents, Industrial phenylacetone (P2P) production from benzene, Synthesis of P2P from P2NP with NaBH4 via K2CO3/H2O2 system.

Difficulty Rating: 3/10​

View attachment 4670 View attachment 4672 ​

Equipment and glassware: View attachment 4673 ​

• 500 mL round bottom flask;
• Reflux condenser;
• Boiling chips;
• Retort stand and clamp for securing apparatus;
• 1 L Separatory funnel;
• Vacuum distillation setup;
• Water bath and ice;
• Heating plate;
• 100 mL x3; 250 mL x2 Beakers;
• pH indicator paper;
• Rotovap machine;
• Vacuum source;
• Laboratory scale (0.01-100 g is suitable);
• Measuring cylinder 10 mL and 100 mL.

Reagents:​

• Phenylacetylmalonate (1) 48.5 mL (55.66 g, 0.20 mole) [Diethyl(phenylacetyl)malonate; cas 20320-59-6];
• Glacial acetic acid (AcOH) 60 mL;
• Concentrated sulfuric acid (H2SO4) 7.5 mL;
• Distilled water ~240 mL;
• Sodium hydroxide (NaOH) solution 20 % ~100 mL;
• Diethyl ether (Et2O) ~150 mL;
• Sodium sulfate (Na2SO4) anhydrous ~100 g;
• Drierite ~50 g (optional).

Procedure​

To a diethyl phenylacetylmalonate (1) 48.5 mL (55.66 g, 0.20 mole) was added a solution of 60 mL of glacial acetic acid, 7.5 mL of concentrated sulfuric acid and 40 mL of water, and the mixture refluxed in 500 mL round bottom flask with reflux condenser for four or five hours until the decarboxylation was complete. The reaction mixture was chilled in an ice-bath, made alkaline with 20 % sodium hydroxide solution, and extracted in a separatory funnel with several portions of ether (~3 x 50 mL). The combined ethereal extracts were washed with water (~200 mL), dried with anhydrous sodium sulfate (Na2SO4) followed by Drierite (optional), and the solvent distilled off. The residue containing the ketone (2) was distilled in vacuo to give 1-Phenyl-2-Propanone (2) in 71 % yield (b.p. 97-98.5 °C/13 mmHg, 214-215 °C/760mmHg).​

View attachment 4671 ​

---

An Alternative Diethyl(phenylacetyl)malonate Hydrolysis to BMK and PAA (phenylacetone and phenylacetic acid)​

Download Video

Easy P2P synthesis from Diethyl(phenylacetyl)malonate

• Novator
• Apr 12, 2023
• 15
• 1-phenyl-2-propanone bmk diethyl(phenylacetyl)malonate hydrolysis methamphetamine p2p paa phenylacetic acid phenylacetone

Diethyl(phenylacetyl)malonate Hydrolysis to BMK and PAA (phenylacetone and phenylacetic acid)...

​

This is an alternative synthesis method which is allow to get Phenylacetone (P2P) from Diethyl(phenylacetyl)malonate. This method consist of Diethyl(phenylacetyl)malonate alkaline hydrolysis into Phenylacetyl-malonic acid sodium salt with subsequent hydrolysis by cheap and easy available hydrochloric acid. In addition, this synthesis way takes less equipment and produce height quality product.​

Equipment and glassware:​

• 5 L Three necked round bottom flask or batch chemical reactor;
• Top stirrer;
• Reflux condenser;
• Retort stand and clamp for securing apparatus;
• 1 L Separatory funnel;
• Water bath and ice;
• 1000 mL x2; 500 mL x2; 250 mL x2 Beakers;
• pH indicator paper;
• Laboratory scale (0.01-100 g is suitable);
• Measuring cylinder 100 mL and 1000 mL;
• Heating plate;
• Filter paper;
• Funnel;
• Frige;
• Glass rod;​

Reagents:​

• Diethyl(phenylacetyl)malonate 800 g (cas 20320-59-6);​
• Sodium hydroxide (NaOH) 115 g;
• Distilled water 1115 ml;
• Hydrochloric acid (HCl aq);

Phenylacetyl-malonic Acid Sodium Salt From Diethyl(phenylacetyl)malonate

1. An alkali aqueous solution 50 % is prepared in advance so that it has time to cool down. Sodium hydroxide 115 g (NaOH) is dissolved in water 115 g and cooled down to room temperature.
2. The cooled NaOH aqueous solution of is poured into a dropping funnel and this funnel is installed onto a reactor.
3. Diethyl(phenylacetyl)malonate 800 g is poured into the reactor. The reaction is carried out at room temperature but a forced cooling can be used during the hydrolysis.
4. A stirrer is turned on and NaOH aq solution adding is begun slowly. Reaction temperature has to be controlled (the mixture is self-heated). As the solution is added, reaction mixture (RM) color is changed and thickened until it is become completely thick and lumpy. The lumps is broken into a homogeneous mass.
5. RM is moved from the reactor to a vacuum filtration system funnel and filtered. Phenylacetyl-malonic acid sodium salt is obtained.​

View attachment 13878 ​

Phenylacetic Acid and Phenylacetone (P2P) synthesis from Phenylacetyl-malonic Acid Sodium Salt​

6. Phenylacetyl-malonic acid sodium salt from the previous step is placed into the reactor and water 1L is added.
7. A reactor jacket is heated up to 60-65°С during a constant stirring. Phenylacetyl-malonic acid sodium salt has to be completely dissolved.
8. After complete dissolution, hydrochloric acid (HCl aq) is added until <3 pH.
9. After about one hour, the phenylacetyl-malonic acid sodium salt hydrolysis is complete. The stirrer is turned off. Layers are separated.
10. While the mixture is still hot, the bottom water layer is drained out and discarded. Layers can be separated by separatory funnel. The top layer is collected.​

View attachment 13879 ​

Phenylacetic Acid and Phenylacetone Separation​

11. During the top layer cooling in a frige, phenylacetic acid is crystallized. The yield is about 400 g of the mixture.
12. After separation by decantation, 200g of phenylacetic acid and 200g of phenylacetone are obtained. A phenylacetone (P2P) purity is quite good for further synthesis without additional purification.​

G.PattonGreat & useful Information. Thanks

 

[MarinaX]

Great & useful Information. Thanks

MonstapointLove it

 

[OrgUnikum]

Guys, do not fall for the cult of the holy reflux. Refluxing has no worth in itself except for the illusion of something happening which it creates.

With H2SO4 and Oxalic acid (best) but Phosphoric Acid and about any organic acid like Acetic or Formic or Citric work one gets next to quantitative yields if one heats up the mixture slowly over two hours to NOT MORE then 95 °C, holds it there for 30 minutes and then let it cool down. Add a small amount of solvent other then DCM (Toluene, Xylene, Ether) as organic acid may fall out and so collecting from top is advised. Petrol Ether 40/60 can be used and not much is needed but you get THREE layers in the end: Top layer is Pet-Ether with P2P dissolved. Middle layer is P2P with Pet-Ether dissolved*. And below is the acid mix (which can be re-used btw. without problems).

*Sounds funny but thats how it is: Both, Pet-Ether and P2P dissolve some of the other one but thex are not freely miscible. And so you get the three layers which drove me next to nuts already a long time ago. Until I figured this out.......

200 g Oxalic Acid Dihydrate
300 ml Water
100 ml H2SO4 37% (battery acid)
not all Oxalic Acid will dissolve - no problem
With this one can process a minimum 200 ml 20230 red oil
Really strong stirring all the time is needed.
The water/acid mix can be re-used.
Not over 95 °C gives light yellow P2P directly without steam or other distillation.
When you use a sep-funnel you best separate as long its still hot and the oxalic does not drop out.Or you put it in a beaker in the freezer with the bottom of the beaker touching the cold so it starts to crystallize from there. If you do this you need no solvent at all, the acid and watere crystallizing from the bottom will drive the P2P to the top and you can just pour it out after two or three hours and NO P2P will be left back.

I did a lot of work on this one, lol

 

[w2x3f5]

Guys, do not fall for the cult of the holy reflux. Refluxing has no worth in itself except for the illusion of something happening which it creates.

With H2SO4 and Oxalic acid (best) but Phosphoric Acid and about any organic acid like Acetic or Formic or Citric work one gets next to quantitative yields if one heats up the mixture slowly over two hours to NOT MORE then 95 °C, holds it there for 30 minutes and then let it cool down. Add a small amount of solvent other then DCM (Toluene, Xylene, Ether) as organic acid may fall out and so collecting from top is advised. Petrol Ether 40/60 can be used and not much is needed but you get THREE layers in the end: Top layer is Pet-Ether with P2P dissolved. Middle layer is P2P with Pet-Ether dissolved*. And below is the acid mix (which can be re-used btw. without problems).

*Sounds funny but thats how it is: Both, Pet-Ether and P2P dissolve some of the other one but thex are not freely miscible. And so you get the three layers which drove me next to nuts already a long time ago. Until I figured this out.......

200 g Oxalic Acid Dihydrate
300 ml Water
100 ml H2SO4 37% (battery acid)
not all Oxalic Acid will dissolve - no problem
With this one can process a minimum 200 ml 20230 red oil
Really strong stirring all the time is needed.
The water/acid mix can be re-used.
Not over 95 °C gives light yellow P2P directly without steam or other distillation.
When you use a sep-funnel you best separate as long its still hot and the oxalic does not drop out.Or you put it in a beaker in the freezer with the bottom of the beaker touching the cold so it starts to crystallize from there. If you do this you need no solvent at all, the acid and watere crystallizing from the bottom will drive the P2P to the top and you can just pour it out after two or three hours and NO P2P will be left back.

I did a lot of work on this one, lol

OrgUnikumindicate the yield of the substance p2p please.
do you have red oil? strangely, I had yellow oil under the same number.

 

[OrgUnikum]

indicate the yield of the substance p2p please.
do you have red oil? strangely, I had yellow oil under the same number.

w2x3f520230-59-6 - Diethyl(phenylacetyl)malonate is supposed to be a dark red oil, it is also so described in the scientific literature.
Its molecular weight is ~278 g, the molecular weight of P2P is ~134 g this says that you can get a maximum of 134 g P2P from 278 g 20230-59-6 - Diethyl(phenylacetyl)malonate or 480 g from one kilo, the maximum theoretical yield being 48 %. I got 45 g pure steamdistilled and dried P2P from 100 g BMK 20230 after finalizing the method and thats as good as it gets, 93 % of whats possible is more then ok with me.

The 20230 is a bit a heavy compound and yields therefor per kilo not so much as other BMKs and its therefor not really cheap but it produces excellent quality easily.

I attach the article where the 20230 is first time synthesized and converted to P2P, look at the very end for the procedure. I replaced the acetic acid with oxalic acid as the oxalic has certain protective properties including scavenging metal ions (often in consumer grade HCl or H2SO4) which could catalyze decomposition of the P2P

PS: I just realized that if the 20230 was prepared by a different pathway then it might not be red but of an milder color, prepared as described in the article its red.

 

[w2x3f5]

20230-59-6 - Diethyl(phenylacetyl)malonate is supposed to be a dark red oil, it is also so described in the scientific literature.
Its molecular weight is ~278 g, the molecular weight of P2P is ~134 g this says that you can get a maximum of 134 g P2P from 278 g 20230-59-6 - Diethyl(phenylacetyl)malonate or 480 g from one kilo, the maximum theoretical yield being 48 %. I got 45 g pure steamdistilled and dried P2P from 100 g BMK 20230 after finalizing the method and thats as good as it gets, 93 % of whats possible is more then ok with me.

The 20230 is a bit a heavy compound and yields therefor per kilo not so much as other BMKs and its therefor not really cheap but it produces excellent quality easily.

I attach the article where the 20230 is first time synthesized and converted to P2P, look at the very end for the procedure. I replaced the acetic acid with oxalic acid as the oxalic has certain protective properties including scavenging metal ions (often in consumer grade HCl or H2SO4) which could catalyze decomposition of the P2P

PS: I just realized that if the 20230 was prepared by a different pathway then it might not be red but of an milder color, prepared as described in the article its red.

OrgUnikumMost likely, oil of varying degrees of purification, although I only hydrolyzed this substance a few times, Google agrees with me that there is red and yellow on sale. It’s good that you found it.
Please don't write 48 percent yield - that's not true, the theoretical yield is always 100 percent. But in terms of moles, you counted everything correctly.
Oxalic acid mixed with acetic acid works, but it seems to me easier with phosphoric acid)))
93% good yield!

 

[OrgUnikum]

Most likely, oil of varying degrees of purification, although I only hydrolyzed this substance a few times, Google agrees with me that there is red and yellow on sale. It’s good that you found it.
Please don't write 48 percent yield - that's not true, the theoretical yield is always 100 percent. But in terms of moles, you counted everything correctly.
Oxalic acid mixed with acetic acid works, but it seems to me easier with phosphoric acid)))
93% good yield!

w2x3f5Well I believe it is important that people know that they can in the best case get 480 g P2P from 1000 g of this BMK whats 48 % w/w.

 

[w2x3f5]

Well I believe it is important that people know that they can in the best case get 480 g P2P from 1000 g of this BMK whats 48 % w/w.

OrgUnikumIt sounds so much better

 

[MarinaX]

Introduction​

This is one of the simplest ways to obtain 1-Phenyl-2-propanone (P2P). Diethyl(phenylacetyl)malonate can be bought in some web market quite easy or synthesized by yourself using this method. Also, you can learn other P2P synthetic paths in our forum by following links: Synthesis of P2P from benzaldehyde with MEK, Synthesis of P2P by oxidation of alpha-methylstyrene with Oxone, Phenylacetone (P2P) syntheses via Grignard reagents, Industrial phenylacetone (P2P) production from benzene, Synthesis of P2P from P2NP with NaBH4 via K2CO3/H2O2 system.

Difficulty Rating: 3/10​

View attachment 4670 View attachment 4672 ​

Equipment and glassware: View attachment 4673 ​

• 500 mL round bottom flask;
• Reflux condenser;
• Boiling chips;
• Retort stand and clamp for securing apparatus;
• 1 L Separatory funnel;
• Vacuum distillation setup;
• Water bath and ice;
• Heating plate;
• 100 mL x3; 250 mL x2 Beakers;
• pH indicator paper;
• Rotovap machine;
• Vacuum source;
• Laboratory scale (0.01-100 g is suitable);
• Measuring cylinder 10 mL and 100 mL.

Reagents:​

• Phenylacetylmalonate (1) 48.5 mL (55.66 g, 0.20 mole) [Diethyl(phenylacetyl)malonate; cas 20320-59-6];
• Glacial acetic acid (AcOH) 60 mL;
• Concentrated sulfuric acid (H2SO4) 7.5 mL;
• Distilled water ~240 mL;
• Sodium hydroxide (NaOH) solution 20 % ~100 mL;
• Diethyl ether (Et2O) ~150 mL;
• Sodium sulfate (Na2SO4) anhydrous ~100 g;
• Drierite ~50 g (optional).

Procedure​

To a diethyl phenylacetylmalonate (1) 48.5 mL (55.66 g, 0.20 mole) was added a solution of 60 mL of glacial acetic acid, 7.5 mL of concentrated sulfuric acid and 40 mL of water, and the mixture refluxed in 500 mL round bottom flask with reflux condenser for four or five hours until the decarboxylation was complete. The reaction mixture was chilled in an ice-bath, made alkaline with 20 % sodium hydroxide solution, and extracted in a separatory funnel with several portions of ether (~3 x 50 mL). The combined ethereal extracts were washed with water (~200 mL), dried with anhydrous sodium sulfate (Na2SO4) followed by Drierite (optional), and the solvent distilled off. The residue containing the ketone (2) was distilled in vacuo to give 1-Phenyl-2-Propanone (2) in 71 % yield (b.p. 97-98.5 °C/13 mmHg, 214-215 °C/760mmHg).​

View attachment 4671 ​

---

An Alternative Diethyl(phenylacetyl)malonate Hydrolysis to BMK and PAA (phenylacetone and phenylacetic acid)​

Download Video

Easy P2P synthesis from Diethyl(phenylacetyl)malonate

• Novator
• Apr 12, 2023
• 15
• 1-phenyl-2-propanone bmk diethyl(phenylacetyl)malonate hydrolysis methamphetamine p2p paa phenylacetic acid phenylacetone

Diethyl(phenylacetyl)malonate Hydrolysis to BMK and PAA (phenylacetone and phenylacetic acid)...

​

This is an alternative synthesis method which is allow to get Phenylacetone (P2P) from Diethyl(phenylacetyl)malonate. This method consist of Diethyl(phenylacetyl)malonate alkaline hydrolysis into Phenylacetyl-malonic acid sodium salt with subsequent hydrolysis by cheap and easy available hydrochloric acid. In addition, this synthesis way takes less equipment and produce height quality product.​

Equipment and glassware:​

• 5 L Three necked round bottom flask or batch chemical reactor;
• Top stirrer;
• Reflux condenser;
• Retort stand and clamp for securing apparatus;
• 1 L Separatory funnel;
• Water bath and ice;
• 1000 mL x2; 500 mL x2; 250 mL x2 Beakers;
• pH indicator paper;
• Laboratory scale (0.01-100 g is suitable);
• Measuring cylinder 100 mL and 1000 mL;
• Heating plate;
• Filter paper;
• Funnel;
• Frige;
• Glass rod;​

Reagents:​

• Diethyl(phenylacetyl)malonate 800 g (cas 20320-59-6);​
• Sodium hydroxide (NaOH) 115 g;
• Distilled water 1115 ml;
• Hydrochloric acid (HCl aq);

Phenylacetyl-malonic Acid Sodium Salt From Diethyl(phenylacetyl)malonate

1. An alkali aqueous solution 50 % is prepared in advance so that it has time to cool down. Sodium hydroxide 115 g (NaOH) is dissolved in water 115 g and cooled down to room temperature.
2. The cooled NaOH aqueous solution of is poured into a dropping funnel and this funnel is installed onto a reactor.
3. Diethyl(phenylacetyl)malonate 800 g is poured into the reactor. The reaction is carried out at room temperature but a forced cooling can be used during the hydrolysis.
4. A stirrer is turned on and NaOH aq solution adding is begun slowly. Reaction temperature has to be controlled (the mixture is self-heated). As the solution is added, reaction mixture (RM) color is changed and thickened until it is become completely thick and lumpy. The lumps is broken into a homogeneous mass.
5. RM is moved from the reactor to a vacuum filtration system funnel and filtered. Phenylacetyl-malonic acid sodium salt is obtained.​

View attachment 13878 ​

Phenylacetic Acid and Phenylacetone (P2P) synthesis from Phenylacetyl-malonic Acid Sodium Salt​

6. Phenylacetyl-malonic acid sodium salt from the previous step is placed into the reactor and water 1L is added.
7. A reactor jacket is heated up to 60-65°С during a constant stirring. Phenylacetyl-malonic acid sodium salt has to be completely dissolved.
8. After complete dissolution, hydrochloric acid (HCl aq) is added until <3 pH.
9. After about one hour, the phenylacetyl-malonic acid sodium salt hydrolysis is complete. The stirrer is turned off. Layers are separated.
10. While the mixture is still hot, the bottom water layer is drained out and discarded. Layers can be separated by separatory funnel. The top layer is collected.​

View attachment 13879 ​

Phenylacetic Acid and Phenylacetone Separation​

11. During the top layer cooling in a frige, phenylacetic acid is crystallized. The yield is about 400 g of the mixture.
12. After separation by decantation, 200g of phenylacetic acid and 200g of phenylacetone are obtained. A phenylacetone (P2P) purity is quite good for further synthesis without additional purification.​

G.PattonAppreciate

 

[rothschild33]

Performed the 20320 -> PAA and Phenylacetone method,


1. An alkali aqueous solution 50 % is prepared in advance so that it has time to cool down. Sodium hydroxide 115 g (NaOH) is dissolved in water 115 g and cooled down to room temperature.
2. The cooled NaOH aqueous solution of is poured into a dropping funnel and this funnel is installed onto a reactor.
3. Diethyl(phenylacetyl)malonate 800 g is poured into the reactor. The reaction is carried out at room temperature but a forced cooling can be used during the hydrolysis.
4. A stirrer is turned on and NaOH aq solution adding is begun slowly. Reaction temperature has to be controlled (the mixture is self-heated). As the solution is added, reaction mixture (RM) color is changed and thickened until it is become completely thick and lumpy. The lumps is broken into a homogeneous mass.

After adding the NaOH, the mixture turns lighter and lighter over the course of minutes getting thicker. Then, at one point the mixture turns back into the color of 20320-59-6.

This was the mixture color after a few minutes of NaOH addition

As time progressed, it started reverting back to the original color:

Then afterwards it just remained in this state:

Anyone know what I can do to fix this, any trial and error / troubleshooting methods?
Also what should I research, what kind of reaction is this, so I could dig deeper into the optimal reaction condition?

 

[rothschild33]

Performed the 20320 -> PAA and Phenylacetone method,


1. An alkali aqueous solution 50 % is prepared in advance so that it has time to cool down. Sodium hydroxide 115 g (NaOH) is dissolved in water 115 g and cooled down to room temperature.
2. The cooled NaOH aqueous solution of is poured into a dropping funnel and this funnel is installed onto a reactor.
3. Diethyl(phenylacetyl)malonate 800 g is poured into the reactor. The reaction is carried out at room temperature but a forced cooling can be used during the hydrolysis.
4. A stirrer is turned on and NaOH aq solution adding is begun slowly. Reaction temperature has to be controlled (the mixture is self-heated). As the solution is added, reaction mixture (RM) color is changed and thickened until it is become completely thick and lumpy. The lumps is broken into a homogeneous mass.

After adding the NaOH, the mixture turns lighter and lighter over the course of minutes getting thicker. Then, at one point the mixture turns back into the color of 20320-59-6.

This was the mixture color after a few minutes of NaOH addition
View attachment 17347


As time progressed, it started reverting back to the original color:

View attachment 17348


Then afterwards it just remained in this state:



View attachment 17349


Anyone know what I can do to fix this, any trial and error / troubleshooting methods?
Also what should I research, what kind of reaction is this, so I could dig deeper into the optimal reaction condition?

rothschild33update: increased the added NaOH solution by 50% and it worked!

 

[qwe111]

Performed the 20320 -> PAA and Phenylacetone method,


1. An alkali aqueous solution 50 % is prepared in advance so that it has time to cool down. Sodium hydroxide 115 g (NaOH) is dissolved in water 115 g and cooled down to room temperature.
2. The cooled NaOH aqueous solution of is poured into a dropping funnel and this funnel is installed onto a reactor.
3. Diethyl(phenylacetyl)malonate 800 g is poured into the reactor. The reaction is carried out at room temperature but a forced cooling can be used during the hydrolysis.
4. A stirrer is turned on and NaOH aq solution adding is begun slowly. Reaction temperature has to be controlled (the mixture is self-heated). As the solution is added, reaction mixture (RM) color is changed and thickened until it is become completely thick and lumpy. The lumps is broken into a homogeneous mass.

After adding the NaOH, the mixture turns lighter and lighter over the course of minutes getting thicker. Then, at one point the mixture turns back into the color of 20320-59-6.

This was the mixture color after a few minutes of NaOH addition
View attachment 17347


As time progressed, it started reverting back to the original color:

View attachment 17348


Then afterwards it just remained in this state:



View attachment 17349


Anyone know what I can do to fix this, any trial and error / troubleshooting methods?
Also what should I research, what kind of reaction is this, so I could dig deeper into the optimal reaction condition?

rothschild33Sir: Have you successfully obtained pure phenyl acetone? Are there any additional steps? Have the ratios of any solvent additions been changed?

 

[OrgUnikum]

BMK 20230 must be done with acid alone, with base you will get not P2P but something else. The author of the original paper used diluted H2SO4 and acetic acid but any mineral acid works, better together with an organic acid. I used HCl or H2SO4 with oxalic acid and it worked great.

Attached the article but beware! The method is not optimized at all. The addition of lye to render the reaction alkaline at the end is outright dangerous as there is a good chance you will polymerize the P2P this way )some of it at least). Its also unnecessary. Also no need to reflux for 3 hours. 90 °C for 30 minutes is fine, but heat it up to this temperature slowly (2 hours).

 

[Xiao hua]

can diethyl malonate instead of diethyl (phenylacetyl)malonate?

 

[HIGGS BOSSON]

can diethyl malonate instead of diethyl (phenylacetyl)malonate?

Xiao huaNo

 

[hy16a]

I don't understand the meaning of 0.2 moles at all. Can 99%CAS 20320-59-6 diethyl phenylacetylmalonate be used directly?