Hello! Yes I was wondering, but I think I confused this with the oxidization. Toluene can be oxidized to benzaldehyde correct? I think I could get by without some of the equipmemt usef in the video. i.e. reactor, rotoevap and overhead stirrer.
Hello! Yes I was wondering, but I think I confused this with the oxidization. Toluene can be oxidized to benzaldehyde correct? I think I could get by without some of the equipmemt usef in the video. i.e. reactor, rotoevap and overhead stirrer.
You can use toluene as a solvent for extraction. You cannot use it for the reaction instead of DMSO. You sir are awesome and I read through your worms quite a bit on the site. So I don't mean to question your expertise on this subject; but I've found multiple online sources talking about the catalytic oxidization of toluene via concentrated H2O2 at 80⁰c. It seems pretty straightforward and on paper the reaction checks out.
You can use toluene as a solvent for extraction. You cannot use it for the reaction instead of DMSO. You sir are awesome and I read through your worms quite a bit on the site. So I don't mean to question your expertise on this subject; but I've found multiple online sources talking about the catalytic oxidization of toluene via concentrated H2O2 at 80⁰c. It seems pretty straightforward and on paper the reaction checks out.
You can oxidize toluene with kmno4, h2o2, etc, but the reaction in the video is a modified swern oxidation which wouldn't work without an alcohol. It will not oxidize a methyl group. Also the oxidation of toluene is difficult to seperate the aldehyde in any kind of high yield, you will mainly get benzoic acid.
You can oxidize toluene with kmno4, h2o2, etc, but the reaction in the video is a modified swern oxidation which wouldn't work without an alcohol. It will not oxidize a methyl group. Also the oxidation of toluene is difficult to seperate the aldehyde in any kind of high yield, you will mainly get benzoic acid.
What was the exact solvent used for the extraction in this video. I know a couple were mentioned, I’m assuming it is DCM because of its low boiling temperature, it would make it quick in easy to strip off in the rotary evaporator ?
So if one where to try to recover the DMSO, where does it go in this reaction ? Does It stay in the Brine solution or does it get carried over with the solvent extraction and distilled of in the rotovap. I thought I understood polarity but after researching it online, I don’t.
In simpleton terms I thought:
You can use toluene as a solvent for extraction. You cannot use it for the reaction instead of DMSO. You sir are awesome and I read through your worms quite a bit on the site. So I don't mean to question your expertise on this subject; but I've found multiple online sources talking about the catalytic oxidization of toluene via concentrated H2O2 at 80⁰c. It seems pretty straightforward and on paper the reaction checks out.
You can oxidize toluene with kmno4, h2o2, etc, but the reaction in the video is a modified swern oxidation which wouldn't work without an alcohol. It will not oxidize a methyl group. Also the oxidation of toluene is difficult to seperate the aldehyde in any kind of high yield, you will mainly get benzoic acid.
I think I have found my answer, Here is the reaction mechanism for the oxidation of benzyl alcohol to benzaldehyde catalyzed by acid in DMSO:
Step 1: Protonation of Benzyl Alcohol
In the presence of acid (such as hydrochloric acid, HCl), the benzyl alcohol (PhCH2OH) is protonated to form a benzyl cation intermediate.
PhCH2OH + H+ → PhCH2OH2+
Step 2: Formation of Carbocation
The protonated benzyl alcohol (benzhydrylium ion) loses a water molecule to form a benzyl carbocation. This step is facilitated by the presence of DMSO, which can act as a dehydrating agent.
PhCH2OH2+ → PhCH2+
Step 3: Oxidation by DMSO
The benzyl carbocation (PhCH2+) reacts with DMSO (dimethyl sulfoxide) as an oxidizing agent, leading to the formation of a benzylsulfoxide intermediate.
PhCH2+ + (CH3)2SO → PhCH2S+(CH3)2
Step 4: Rearrangement of Benzylsulfoxide
The benzylsulfoxide undergoes a rearrangement, facilitated by the presence of acid, to form a new intermediate called a benzyl-sulfinic acid.
PhCH2S+(CH3)2 → PhCH2S(=O)OH(CH3)
Step 5: Homolytic Cleavage
Under acidic conditions, the benzyl-sulfinic acid undergoes homolytic cleavage to form a benzyl radical and a sulfinate anion.
PhCH2S(=O)OH(CH3) → PhCH2• + OSO2(CH3)–
Step 6: Reaction with Oxygen
The benzyl radical reacts with oxygen present in the reaction mixture to form a benzyl peroxy radical.
PhCH2• + O2 → PhCH2OO•
Step 7: Decomposition of Peroxy Radical
The benzyl peroxy radical decomposes to form a benzaldehyde molecule and a hydroperoxy radical.
PhCH2OO• → PhCHO + •OOH
Step 8: Rearrangement and Elimination
The hydroperoxy radical can undergo rearrangement and elimination reactions to regenerate the catalyst (e.g. DMSO) and produce water.
•OOH → DMSO + H2O
Overall Reaction:
The overall reaction for the oxidation of benzyl alcohol to benzaldehyde catalyzed by acid in DMSO can be represented as follows:
PhCH2OH + DMSO + O2 → PhCHO + DMSO + H2O
Note: The above mechanism is a simplified representation of the process. There might be additional steps or side reactions that can occur depending on the specific reaction conditions and catalyst used.
DMSO (Dimethyl Sulfoxide) is not converted into DMS (Dimethyl Sulfide). DMSO serves as a solvent in this reaction and acts as a coordinating solvent for the acid catalyst. It does not undergo any conversion or reaction itself.
So in theory all of the DMSO in the reaction can be recovered
