Oh, I thought MnSO4 + H2SO4, while concentrated produced Mn persulfate easily, at least more easily then MnO2. But now that I think about it the MnO2 probably plays an important roll in making the Mn persulfate in the first place when heating the H2SO4.

Mn2O7 with ANY organic is stupidity. I got it to ignite with sodding powdered rubber, gasoline, diesel, oil, paper, cotton, plastics, sugar, and it burned my flesh and felt like skin was aflame! With Xylene it goes BANG. I wonder how Turpentine reacts, its supposedly a cery reactive reducer. Somethingymajiggy (yep this is a word!) about the unsaturated C-1 terpene or some such bullshit, I was half asleep that day. Basically its reactive as fuck. Anyone got a structure of Turpentine for me? Or is it a mixture? All I know is that its good in ANFO and a paint stripper and it lights from CL2 and its hydrocarbon

ANYWAYS, enough off topic. Playing with Mn2O7 is like making a big huge massive multi kilo pile of dry AP and smoking while playing with sparklers and sitting on it! NOT safe.

My results here are screwing my head up terribly and all I want to know is how concentrated my BnO is.

The adduct hardly has been forming at all and has been erratic to say the lest. That made me believe that there was alot of BnO at first then very little BnO after other test....

Then. I decided to get a better idea by using (aq)NH3 to form the trimmer product of BnO and all but a trace amount of the oil went into solution as a milky white suspension indicating a high degree of conversion to Benzaldahyde.

Non of this is quantative data and the only way I see around this to determine my concentration is to bubble dry NH3 into a known volume and weighing the solid ammonia product that precipitates. Chi told me this undergoes hydrolysis in hot H2O but I have a hard time believing that BnO would be the product and I feed that BnOH seems more likely of a product.

Does anyone have any information of the hydrolysis of Hydrobenzamide?


[EDIT]

Just went A lookin ...... And I am happy to announce that Chi is right 100% and I am wrong. For once I am very pleases to say im wrong. Under acidic conditions Hydrobenzamide undergoes hydrolysis to BnO and ammonia so this seems like an idea way to extract my BnO from the solution.

Here is the quote that google turns up, I don't have access to the full paper though. Im going to figure out how to make the douments think Im google sooner or later.

The ready hydrolysis of hydrobenzamide by acids into benzaldehyde and ammonia is a characteristic reaction, but its stepwise decomposition by ...

http://pubs.acs.org/doi/abs/10.1021/ja01338a042

More to come......

And it all turns into benzaldehyde?
It seems like it would be a possibility that some of it could turn into benzyl alclohol, etc.

This is great though.

If one were to ever do such a pointless thing, it could make it easy to produce lots of benzaldehyde. Mn persulfate oxidation, react with toluene, shake in ammonia, separate remaining toluene to be re-used, and then add an acid to get the purified benzaldehyde.

hydrobenzamide isn't regulated and I'd bet is probably is more stable = better to keep it in that form anyways..

Does contamination of other metals cause problems? Considering your source of sulfuric acid and MnO2, they might be playing a roll in the low yield?

Oh and just curious, what is it you are basing your yield off of? The Mn persulfate, or the toluene?

Well, if it weren't for the fact that Fe reacted with sulfuric acid you could always count on this:
CuSO4 + Fe = FeSO4 + Cu
FeSO4 + O2 = Fe2O3 -- precipitating both metals and leaving an acid.

The Cu shouldn't react, unless it is more reactive then manganese, which doubt it is.

It will be interesting to hear any results you might get Vesp. On a whim I would think that the mixture of Sodium and Mangenese persulfate would be strong enough to take things right to the carboxylic acids which will be nice to get a quantitive oxidiser on the cheep for making Glacial acetic acid from Ethanol or just as useful Formic acid from Methanol.


Im starting to get up on my feet again but it may be some time before I get my self into anything major. I started to clean my MnSO4 yesterday by filtering thru a fritted glass and now im going to wash the hell out of it with ether when I get the chance because the smell of Cherrys and crud is really powerful comming off of the solution. I figure best bet is to boil some air thru the solution and see if I can precipitate any FeSO4 and then condense and recrystalize after washing the whole mess with alot of ether to rid organic. As for the Cu contamination I can see it there when I drip it on zinc and where as I don't think theres alot I am a purity freak and wanna find a way to remove it.

I didn't want to post to this thread before I had a little experience with the topic. I didn't want to look clueless when I have the opportunity to go all the way to stupid! So here goes.

I've tried making Mn(SO4)2 several times, now. The first couple were very sloppy, I guess to convince myself that it could really be done. Both times the result was that I got a little whiff of cherries (almond), but there wasn't enough quantity to amount to anything.

I tried to do it right the next time, and things were looking better. I have a beaker with a nice layer of pink goo at the bottom. It's the color of Pepto Bismol. This fell out of solution as I was heating the pretty pink--almost cherry red--solution of MnSO4. I separated it out from the liquid and continued heating, thinking there would be more, but something else seemed to be coming out instead. It was more of a clear or brownish crystal. What was left of the liquid was now dark brown. I thought maybe I needed to add more acid and cook it again, so I tried that but nothing changed.

I was puzzling over this so I went back to look again at the patent. (US patent #837,777) That's when I happened to re-read Example 4--"In solution", which says:

- - - - - - -
"Example 4. Manganese Peroxid Sulfate by the Interaction of Manganous sulfate and Permanganate.

a) In solution.--Dissolve one hundred and sixty-nine (169) parts of manganous sulfate dried at one hundred and fifty degrees C. (MnSO4.H2O) in forty seven hundred and eighty (4,780) parts of sulfuric acid containing about seventy percent of H2SO4 and add one hundred and eight (108) parts of finely powdered potassium permanganate in small portions at a temperature of from fifty to sixty degrees C while stirring well. Red manganic sulfate is at first formed. It is then converted into the brown manganese peroxid sulfate. Instead of manganous sulfate the equivalent quantity of manganic sulfate can be employed, in which case only half the above quantity of permanganate is necessary."
- - - - - - -

I realized that I had essentially followed the instructions from this example, and converted a lot of my MnSO4 into MnSO4.H2O. So I followed the rest of the instructions, meaning I added a little KMnO4 with stirring at 50-60C, and right away I had Mn(SO4)2! That easy. Just add a little potassium permanganate, stir, and I was good to go. I couldn't believe it, but it's easier and much quicker than the electrolysis, and I liked that.

I decided next to use it to make some benzaldehyde as a sanity check. I was adding the Mn(SO4)2 a little bit at a time like the patent said I should, although it didn't say how much "a little bit at a time" is--so I used about 1 ml, and then waiting until it looked like it was played out before adding more. I got tired of that after awhile, so I added more. This time it might have been 3-5 ml all at once, maybe a bit less. The instant it hit the toluene there was a bright flash as a blue flame suddenly popped into existence inside the flask. It wasn't at all like something had burned, and there was still a lot of toluene left over afterward. I lightly plugged the flask because it was producing white vapors and I didn't know what they were. The flash was so close to being an explosion that I had to sit down for awhile to reassure myself that it hadn't just blown up in my hand.

I think the reason may have been that I had a few grains of KMnO4 too much, and which never dissolved in the liquid. I don't know if toluene and KMnO4 dislike each other that badly, but if not it was the reaction between the persulfate and the toluene. In my mind this last would be worse. The bottom line, though, is when the guy who wrote the patent says to do something a little bit at a time, his reason may be other than to help you maximize yields. It would have been nice if he had stated his reasons. I didn't expect anything like that to happen. Not at all!

Still, this is a really easy procedure, but there's one other problem with it as written, at least for me. That's that the author leaves too much between the lines. For example, I found it impossible to get the pink MnSO4 to dry out completely. The patent author doesn't explain how to do this, yet he measures everything by weight. I had no way to do the calculations as he did, hence the reason I may have added a bit too much KMnO4. There are several other similar examples in the patent.

If anyone has a good idea what I did wrong that caused my near explosion I'd sure appreciate knowing what it is.

I might mention that the Mn(SO4)2 that I made last night settled out in the container overnight, and this morning looked exactly as the patent author described it. For obvious reasons I haven't tried it again on toluene. Not until I learn more!

Cheers,
PP

Here are a few more notes on my experiments, detailed in the previous post.

In each case I started with MnO2 from fresh super heavy duty batteries. I washed the black mush just as sedit details, but stopped using HCl prior to adding H2SO4 because it makes a hell of a lot of chlorine. With fresh batteries I don't think there's much that you have to worry about mixed into it, but by the time you finish it should be gone anyway. Or so I reasoned.

After the water wash it's really hard to decant the liquid because the MnO2 is so slippery and tends to pour off with the water. I finally dealt with it by placing a Charmin plug in a funnel, with a piece of filter paper on top of that. I placed the funnel in a vacuum flask and pulled the liquid through, and it came through without any MnO2. Then I rinsed the filter cake with acetone to get the last of the water out and dry it quickly.

This method of filtration does not work once the H2SO4 has been added. Not thinking I tried it, and the Charmin plug very quickly turned into a mass of quivering gel.

sedit has been doing the elctrolysis at a very high current density--was it fifteen amps? The patent author says likewise. Personally, I don't know how this is possible. When I was doing electrolysis I had the supply set for ten volts and the solution was drawing about 30 mA. If I turned the voltage higher to increase the current, the solution would start to react furiously, and had I left it like that it would have become so hot it would have cooked itself away. At 30 mA I could watch the red material being formed quickly, and it only took a few minutes to react everything I had in the small container. Maybe others are processing much larger quantities than I was. Electrode placement makes a difference too, but not that much!

When heating the MnO2 to form MnSO4, every time I've done this I've had to use a propane torch to get the solution hot enough to boil. I've tried to be very conservative in applying the heat and don't think I've gotten it significantly hotter than it should be. The reason I have to do this is that H2SO4 boils at about 300C and my hotplate can't do it.

The white fumes that come off during the conversion of MnO2 to MnSo4 are not sulfuric acid. I don't know what they are, but I dampened a piece of indicator paper and held it in the fumes. The PH was 7.

Every time I've done the process of changing MnO2 to MnSO4, the mixture has reached a point right after the first wisps of white fumes come off where the process nearly runs away from me. The first time I tried it I had the flask connected to a distillation tube, and it blew some of the contents of the flask into the tube. The flask was a 300 ml one, and I had less than 1/2 inch of materiial at the bottom. I quickly began stirring and took it off the heat, and this avoided any additional overflowing. I am now very careful when I get near the same point, but even so it happens very quickly. Constant stirring helps a lot, but is no guarantee.

When I had the near explosion detailed in the previous post, sedit thinks I may have made Mn3O7.... VERY VIOLENT OXIDISER. That certainly sounds worth considering, but doesn't agree with what the patent author says. I'd rather not blow myself up, though, so I'd appreciate it if anyone with additional information would speak up.

PP

Since you where having trouble drying your MnSO4 there was almost no doubt some H2SO4 in there. You can wash this sparingly with some H2O and it should dry nicely after that.

There is also the possibility that such as you said and some KMnO4 was still present causing the flashes. Check out the gummy bear permagnate experiments on you tube and see if that discribes what you seen. Still though if it was "wet" then there is good odds that some of the permagnate was converted to the heptoxide.

What did we learn today about chucking strong oxidisers into organic solvents class .


PS: Can you link the patent PP if it has not been done already. I don't remeber reading where they regenerated with KMnO4 but I also was more concerned with electro synthesis anyway.