Phenylacetone (P2P) synthesis from benzaldehyde with butanone
- Thread starter WillD
- Start date
distilled or evaporated under vacuum, at what temperature is it heated, evaporated or distilled? and how many hours will it be distilled
The reference is 270C as the boiling point. I do wonder if the solvent can be removed and just use it as is in step 2.
I need help!
100g of both Benzaldehyde and MEK were added to a 500ml RBF and chilled to zero. The mixture was put on mag Stir and HCL was bubbled through the solution, quickly at first and then slow and steady once the HCl generator was fine tuned. (HCl over Conc. Sulphuric Acid). The solution turned yellow, then red, followed by very dark red. After 1.5 Hours, gas was removed and let stir at room temperature for 1.5 hours. Added 200ml of distilled water, instantly two layers formed. A dark layer (organic bottom) and a aqueous layer clear yellow. 40ml of DCM was added to the solution.
Here is my problem. The DCM appears to have merged with the organic layer. It's a lovely smelling camphur solution, actually it's a beautiful smell. However I cannot see the DCM layer in the sep funnel. Damn, how the fuck to resolve this?
100g of both Benzaldehyde and MEK were added to a 500ml RBF and chilled to zero. The mixture was put on mag Stir and HCL was bubbled through the solution, quickly at first and then slow and steady once the HCl generator was fine tuned. (HCl over Conc. Sulphuric Acid). The solution turned yellow, then red, followed by very dark red. After 1.5 Hours, gas was removed and let stir at room temperature for 1.5 hours. Added 200ml of distilled water, instantly two layers formed. A dark layer (organic bottom) and a aqueous layer clear yellow. 40ml of DCM was added to the solution.
Here is my problem. The DCM appears to have merged with the organic layer. It's a lovely smelling camphur solution, actually it's a beautiful smell. However I cannot see the DCM layer in the sep funnel. Damn, how the fuck to resolve this?
So I separated and did a DCM extraction on the Aqueous phase. Nothing was left after evaporation of DCM. I'm thinking I'm going to have to distill everything in the organic phase and see whats left over as a solid.
This is a real pain, has anyone done this synth successfully? Can anyone tell me if DCM is the issue. I don't want to make Chloroform or buy it
This is a real pain, has anyone done this synth successfully? Can anyone tell me if DCM is the issue. I don't want to make Chloroform or buy it
Unfortunately my glass thermometer broke, so I couldn't read off the fractions. Managed to pull a clear layer of what smells like DCM and HCL. I changed over to an oil bath and got over smoke temp of veg oil around 220, switched on vacuum and pulled a pale yellow oil over. It's an effort without short path to bring the column up to such a high temp. I figure I was pulling over around 200.
I don't think the oil is going to crystallise so I think next step will be DCM extract on the distillate.
I don't think the oil is going to crystallise so I think next step will be DCM extract on the distillate.
So that was a complete failure. DCM dissolves straight into the yellow distillate.
Now I imagine Chloroform would behave the same way. This is really annoying.
Now I imagine Chloroform would behave the same way. This is really annoying.
- By waltjr5858
Use toulene Next time. Much cheaper and easier than chloroform. But yes these solvents should Mix right in with the yellow layer If you mean the organic layer Because they absolutely mix. Now if you're extracting from A water mix Toss some toulene On top And the oil Absolutely migrate over Then just distill off the toulene And reuse. The only way to extract A solvent From the organic layer Is too distill it off.
Aldol Condensation.
The directions for this are in Organic Reactions
This write up seems to be more inline with what I am seeing. Has anyone actually tried to extract with solvent from the organic layer. Using chloroform won't work, as it's miscible with the organic layer. Unless I'm missing something the write up needs to be tested and modified.
Anyone tried this synth before.
The directions for this are in Organic Reactions
This write up seems to be more inline with what I am seeing. Has anyone actually tried to extract with solvent from the organic layer. Using chloroform won't work, as it's miscible with the organic layer. Unless I'm missing something the write up needs to be tested and modified.
Anyone tried this synth before.
I put the distillete in the freezer over night, nothing happened, I dipped a frozen spoon into the mix and it instantly crystalized. Quite extraordinary. I'll move onto step 2.
Why is the first two reactants quoted in MLS, and the H2O2 is quoted in grams. Another point if confusion in this write up.
Can someone please explain, how extraction with Chloroform works when the product is not in the Aqueous phase. Your Chloroform will merge with the organic layer, and you will have 1 phase.
What this should read-
What this should read-
This may prove useful to some for step 2.
Using a common OTC laundry oxidation powder resulted in the baeyer villager reaction success with a yield of 43%.
Using a common OTC laundry oxidation powder resulted in the baeyer villager reaction success with a yield of 43%.
Variation to step 1.
If you are having trouble generating stable dry HCL it seems you can just use NaOH and stir overnight. Yields are lower but your not dealing with the hassle of generating HCL gas.
If you are having trouble generating stable dry HCL it seems you can just use NaOH and stir overnight. Yields are lower but your not dealing with the hassle of generating HCL gas.
C
Can you be specific?
The thermometer was broken, but to distill:
1-methyl-4-fenyl-3-Buten-2-one It was very hot. Without short path distillation and only a 40cm fractional column. It is such a pain to get that to come over even with a vacuum. an oil bath with vegetable oil at smoke temp cleared a clear liquid that was very HCl saturated, and also the DCM that failed to separate. I turned on vacuum and pulled a thin yellow oil above 200. The distillation flask becomes very thick before you can pull it all over. You can read about xtal formation in my earlier posts.
After the oxidation there was no more need for Distillation but you need to make a separation plan early. Even on a <50g scale there is a lot of liquid to extract from. The DCM in this step works really well as you can decant most of the liquid off and then use a sep funnel to get the DCM layer. Unfortunately my vacuum pump broke
so I had to try evap the solvent without vacuum. It's possible but I don't recommend. The volatiles coming off with the DCM are not nice at all. I ended up pouring the last if the DCM into a Pyrex tray and let evap over night. So that adds a whole day into an already 3 day process.
Can you be specific?
The thermometer was broken, but to distill:
1-methyl-4-fenyl-3-Buten-2-one It was very hot. Without short path distillation and only a 40cm fractional column. It is such a pain to get that to come over even with a vacuum. an oil bath with vegetable oil at smoke temp cleared a clear liquid that was very HCl saturated, and also the DCM that failed to separate. I turned on vacuum and pulled a thin yellow oil above 200. The distillation flask becomes very thick before you can pull it all over. You can read about xtal formation in my earlier posts.
After the oxidation there was no more need for Distillation but you need to make a separation plan early. Even on a <50g scale there is a lot of liquid to extract from. The DCM in this step works really well as you can decant most of the liquid off and then use a sep funnel to get the DCM layer. Unfortunately my vacuum pump broke
so I had to try evap the solvent without vacuum. It's possible but I don't recommend. The volatiles coming off with the DCM are not nice at all. I ended up pouring the last if the DCM into a Pyrex tray and let evap over night. So that adds a whole day into an already 3 day process.
