While looking for something else, I did find a paper that oxidises pyridine to the N-oxide in quantitative yield using cyclohexanone dioxirane (compound h). I don't have any experience with the cyclohexanone version, but have worked with DMDO extensively in the past with a lot of success. The only obvious concern is in terms of safety - dioxiranes tend to be vigorously unstable. DMDO you make at such low concentrations that the risk is negligible, or you generate it in situ; I wonder if you couldn't adapt their procedure to use in situ generation of the cyclohexanone dioxirane as well.
While looking for something else, I did find a paper that oxidises pyridine to the N-oxide in quantitative yield using cyclohexanone dioxirane (compound h). I don't have any experience with the cyclohexanone version, but have worked with DMDO extensively in the past with a lot of success. The only obvious concern is in terms of safety - dioxiranes tend to be vigorously unstable. DMDO you make at such low concentrations that the risk is negligible, or you generate it in situ; I wonder if you couldn't adapt their procedure to use in situ generation of the cyclohexanone dioxirane as well.
I know that you can make pertrifluoroacetic acid from trifluoroacetic acid and sodiumpercarbonate, this is a strong reagent. I dont have a reference, sorry. You should find in in Fieser&Fieser Reagents for Organic Synthesis I think.
I know that you can make pertrifluoroacetic acid from trifluoroacetic acid and sodiumpercarbonate, this is a strong reagent. I dont have a reference, sorry. You should find in in Fieser&Fieser Reagents for Organic Synthesis I think.
Thanks guys, I think I found the review (not sure if its the exact one, Im at home atm) but they mention UHP+TFAA and it seems to work. Might have to fiddle with the equivalents a bit but it works at room temperature
Thanks guys, I think I found the review (not sure if its the exact one, Im at home atm) but they mention UHP+TFAA and it seems to work. Might have to fiddle with the equivalents a bit but it works at room temperature
Hopper had a review in 2009 in Progress in Heterocyclic chemistry. The reagents discussed are MCPBA, peracetic acid, peroxy triflic acid, urea - peroxide complex, and triflic anhydride with sodium carbonate and hydrogen peroxide. The last one is supposed to be good for resistant pyridines.
Do you really mean triflic anhydride? Trifluoromethanesulphonic anhydride? A question is do you get bad conversion or byproduct formation? If the latter it does not help with stronger oxidizer maybe?
Hopper had a review in 2009 in Progress in Heterocyclic chemistry. The reagents discussed are MCPBA, peracetic acid, peroxy triflic acid, urea - peroxide complex, and triflic anhydride with sodium carbonate and hydrogen peroxide. The last one is supposed to be good for resistant pyridines.
Do you really mean triflic anhydride? Trifluoromethanesulphonic anhydride? A question is do you get bad conversion or byproduct formation? If the latter it does not help with stronger oxidizer maybe?
While looking for something else, I did find a paper that oxidises pyridine to the N-oxide in quantitative yield using cyclohexanone dioxirane (compound h). I don't have any experience with the cyclohexanone version, but have worked with DMDO extensively in the past with a lot of success. The only obvious concern is in terms of safety - dioxiranes tend to be vigorously unstable. DMDO you make at such low concentrations that the risk is negligible, or you generate it in situ; I wonder if you couldn't adapt their procedure to use in situ generation of the cyclohexanone dioxirane as well.
https://doi.org/10.1021/ja00030a032
Thanks, I tried running the raction in acetone and using oxone to make it in situ but didnt work. However, I got full conversion using TFA+H2O2 or TFAA+UHP so Im fine now THanks for help guys
While looking for something else, I did find a paper that oxidises pyridine to the N-oxide in quantitative yield using cyclohexanone dioxirane (compound h). I don't have any experience with the cyclohexanone version, but have worked with DMDO extensively in the past with a lot of success. The only obvious concern is in terms of safety - dioxiranes tend to be vigorously unstable. DMDO you make at such low concentrations that the risk is negligible, or you generate it in situ; I wonder if you couldn't adapt their procedure to use in situ generation of the cyclohexanone dioxirane as well.
https://doi.org/10.1021/ja00030a032
Thanks, I tried running the raction in acetone and using oxone to make it in situ but didnt work. However, I got full conversion using TFA+H2O2 or TFAA+UHP so Im fine now THanks for help guys
Hopper had a review in 2009 in Progress in Heterocyclic chemistry. The reagents discussed are MCPBA, peracetic acid, peroxy triflic acid, urea - peroxide complex, and triflic anhydride with sodium carbonate and hydrogen peroxide. The last one is supposed to be good for resistant pyridines.
Hopper had a review in 2009 in Progress in Heterocyclic chemistry. The reagents discussed are MCPBA, peracetic acid, peroxy triflic acid, urea - peroxide complex, and triflic anhydride with sodium carbonate and hydrogen peroxide. The last one is supposed to be good for resistant pyridines.
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https://doi.org/10.1021/ja00030a032
https://doi.org/10.1021/ja00030a032
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Here is a reference:
https://www.organic-chemistry.org/chemicals/oxidations/trifluoroacetic-peracid.shtm
Here is a reference:
https://www.organic-chemistry.org/chemicals/oxidations/trifluoroacetic-peracid.shtm
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Do you really mean triflic anhydride? Trifluoromethanesulphonic anhydride?
A question is do you get bad conversion or byproduct formation? If the latter it does not help with stronger oxidizer maybe?
Do you really mean triflic anhydride? Trifluoromethanesulphonic anhydride?
A question is do you get bad conversion or byproduct formation? If the latter it does not help with stronger oxidizer maybe?
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Thanks, I tried running the raction in acetone and using oxone to make it in situ but didnt work. However, I got full conversion using TFA+H2O2 or TFAA+UHP so Im fine now
THanks for help guys
Thanks, I tried running the raction in acetone and using oxone to make it in situ but didnt work. However, I got full conversion using TFA+H2O2 or TFAA+UHP so Im fine now
THanks for help guys
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