Synthesis of P2P by oxidation of alpha-methylstyrene with Oxone (Potassium Peroxomonosulfate) (1kg scale)
- Thread starter WillD
- Start date
Nice. I found and attached the article and well, you miscalculated the amount of Oxone needed. You need 2 molar equivalents of Oxone and Oxone has a molecular weight of ~630 g/mol. a-methylstyrene has a mol weight of 118 g/mol and so 1 kg is about 8,5 mol. This by two and then by the Oxone mol weight and we get a whopping 10.700 g lets say 11 kg. And thats the problem. Otherwise it would be better then sliced bread as I can buy the styrene for less the 10 € per liter. Damn!
Nevertheless a great method and iodohydrin synthesis is something what comes handy in other places and very handy indeed.
And yes I calculated that correctly, I know of the nonsense that Oxone is sometimes said to have 314 g/mol but as half-molecules do not exist thats nonsense. It is 630 g/mol and it has 2 OXIDATIVE equivalents per mol. I attach another paper where you can see that at least 1,5 OXIDATIVE equ. are needed to get to the iodohydrin so with only two of those at all it cannot work.
Yields in the article were 81%, that would be 922 g, we usually do not get what those guys get, 800 g would be a realistic great result I would say.
Maybe this could be done with another oxidizer? Something less bulky. H2O2 should work, if somebody has access to concentrated H2SO4 and 30%+ H2O2 then Caros acid could be used and the volume greatly reduced. Just as a quick but sure shot.
sir i want to do this in 10 liter flask for testing sir can you help me with that should i divide everything with 20?
Sir, I can get all the reagents I need, but the consumption of acetonitrile and Oxone is too large, and the value of completing the experimental P2P will be very expensive. Is there any reagent that can replace acetonitrile? Or do you already have a more reasonable way to complete this work?
You can replace it with ethanol
200L reactor to get only 1kg of P2P?
- By lalalander
Yes. But hey! It is practically dump it all and stir. The only labor-intensive part is the extraction.
- By OrgUnikum
Oxone is the so called triple salt and consists of potassium peroxymonosulfate the actual oxidizer, potassium sulfate and potassium disulfate in the ratios 2 to 1 to 1 molar. So obviously there comes a lot of unwanted stuff which takes up a lot of volume as the persulfate makes up only about45% of the total weight.
This matters as you need 11 kg of Oxone per kg of methylstyrene.
Plus iodine, thats not a cheap way - you get 970 g of P2P at best.
But regarding solvent volume: It is possible to extract the persulfate from the Oxone and to use this alone what reduces solvent volume by half rather more. Ten to twenty liter should be enough. Some other approach then "sump all in" for adding reagents could reduce this even further.
The 200 liter are a joke which is caused by extrapolating numbers from millimol in articles to fictive 1kg reactions. It does not work this way.
This matters as you need 11 kg of Oxone per kg of methylstyrene.
Plus iodine, thats not a cheap way - you get 970 g of P2P at best.
But regarding solvent volume: It is possible to extract the persulfate from the Oxone and to use this alone what reduces solvent volume by half rather more. Ten to twenty liter should be enough. Some other approach then "sump all in" for adding reagents could reduce this even further.
The 200 liter are a joke which is caused by extrapolating numbers from millimol in articles to fictive 1kg reactions. It does not work this way.
Oxone is the so called triple salt and consists of potassium peroxymonosulfate the actual oxidizer, potassium sulfate and potassium disulfate in the ratios 2 to 1 to 1 molar. So obviously there comes a lot of unwanted stuff which takes up a lot of volume as the persulfate makes up only about45% of the total weight.
This matters as you need 11 kg of Oxone per kg of methylstyrene.
Plus iodine, thats not a cheap way - you get 970 g of P2P at best.
But regarding solvent volume: It is possible to extract the persulfate from the Oxone and to use this alone what reduces solvent volume by half rather more. Ten to twenty liter should be enough. Some other approach then "sump all in" for adding reagents could reduce this even further.
The 200 liter are a joke which is caused by extrapolating numbers from millimol in articles to fictive 1kg reactions. It does not work this way.
This matters as you need 11 kg of Oxone per kg of methylstyrene.
Plus iodine, thats not a cheap way - you get 970 g of P2P at best.
But regarding solvent volume: It is possible to extract the persulfate from the Oxone and to use this alone what reduces solvent volume by half rather more. Ten to twenty liter should be enough. Some other approach then "sump all in" for adding reagents could reduce this even further.
The 200 liter are a joke which is caused by extrapolating numbers from millimol in articles to fictive 1kg reactions. It does not work this way.
You need potassium peroxymonosulfate, KHSO5, peroxysulfate is the di-sulfate and has to be converted to the monosulfate first to work. But if you use the di-sulfate sodium peroxysulfate is the better choice as it has a much higher solubility and allows to reduce solvent volume. AFAIK the üperoxy-di-sulfates are hydrolyzed to the monosulfates at temperatures >55°C.
Caros Acid aka Piranha solution made from H2O2 50% and >70% H2SO4 can also be used, thats is the correspondensing acid to peroxy monosulfate.
Caros Acid aka Piranha solution made from H2O2 50% and >70% H2SO4 can also be used, thats is the correspondensing acid to peroxy monosulfate.
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- By OrgUnikum
Also 50% H2SO4 converts sodium or potassium persulfate into persulfuric acid what is Caros acid.
One mol Oxone has 630 g and contains two oxidation equivalents. One mol of Caros acid has one oxidation equivalent.
As with all per-compounds it is a good idea to add something what prevents decomposition, say oxygen just bubbling off for nothing. Oxalic acid, Sodium Stannate and EDDTA can be used, best in combination. Only small amounts are needed, say a teaspoon to 2 liter reaction? Should do the trick.
One mol Oxone has 630 g and contains two oxidation equivalents. One mol of Caros acid has one oxidation equivalent.
As with all per-compounds it is a good idea to add something what prevents decomposition, say oxygen just bubbling off for nothing. Oxalic acid, Sodium Stannate and EDDTA can be used, best in combination. Only small amounts are needed, say a teaspoon to 2 liter reaction? Should do the trick.