Sciencemadness Discussion Board

dimethylformamide

greenyppols - 7-7-2005 at 19:21

I'll probably get slapped for this, I have googled this and searched various forums. This one too. Cant find how this would be made or if it was possible. Perhaps a nudge in the right direction where to look?
Thanks

IrC - 7-7-2005 at 20:08

You are right you should. Took 30 seconds to find a patent on it's synthesis. Extremely dangerous solvent used in making polyurethane, on at least 4 federal regulatory lists. I hope your chemistry skills are better than your searching skills. If not do not read this link.

http://www.freepatentsonline.com/4251460.html

chromium - 7-7-2005 at 21:50

Following US patents are also about DMF synthesis: 1777777, 2204371, 2677706, 2866822, 3412151, 4218398, 4558157, 4853485, 6723877
Just curious, has anyone here worked with this solvent?

greenyppols - 8-7-2005 at 02:46

Sorry I dont have your searching fortitude, IrC. I also found that freeonlinepatent thing..less than 30 seconds though. Maybe I should be more specific and post all my ?s at 11pm after being awake all day?
My chemistry skills? Sorry bub, I never claimed to be a chemist.
If I were, I would have chemist buddies to tolerate my dumb ?s, instead of a professor convinced everyone wants to be like (insert name of your favorite drug lord or baddie here)but more likely I wouldnt have any questions, as I'd BE a chemist.
At least a chemist not posting here.

Extememly Dangerous solvent? No Shit, Sherlock. 4 federal lists? Tell me something I dont know, but what if I was looking on behalf of a family member in Canada? Which "federal list" are you referring? US, or Canada? Or elsewhere?
I was looking for something like..a setup for how this is made. I found setups for ammonia, chlorine, hydrogen, CO2 and such. Even a diagram of the FatMan atomic bomb. With pictures, too!
The reason I posted here is, some clown (I hope, or I have crow to eat) tried to tell me acetone was the same damn thing. Acetone??????? Thats why I posted here.
Imitation is the sincerest form of flattery, I say, and little of anything I've read here is what I'd say is "where no man has gone before." Just following in someone else's footsteps.
I always figured it didnt hurt to ask, I could be wrong.

Yea, I know my posts arent the brightest, Thanks for pointing it out.

Thanks for the info chromium. And not for venting your spleen as I just have. I have better places to look now.

Tacho - 8-7-2005 at 03:44

I'm not a chemist either, but here goes what I know:

DMF and acetone are not the same thing but they are both aprotic solvents, that is, they don't have H+ ions floating around like acetic acid or water. In a rather empirical substitution list, the closest solvent to DMF is DMSO, folowed by acetone.

DMF is thicker then acetone and smells like fish soup gone sour.

DMSO is quite harmless. In my opinion, DMF is not extremely dangerous, but should be handled with care. Check the info about it and come to your own conclusions. I suggest you use the google-groups search, that will give you access to the usenet, and the posts of people who had first hand experience with it.

jimwig - 8-7-2005 at 12:47

oh boy here goes

looking at the molecular models of dmf, dmso and acetone.

engaging and changing that central atom be it S, CH2, or whatever is probably fairly difficult, right?

the patent says ammonia and methanol react to give methylamine and then onward via co2 to dmf.

the pictures sure don't give a clue. ain't chemistry funny, guess i had better get more than a degree in cartoons.

chemoleo - 8-7-2005 at 16:35

IrC, it isn't THAT dangerous, there are far more dangerous ones. We use DMF for peptide synthesis, and yes, its viscosity seems fairly high, and it smells. The BDH and Sigma bottles just have an irritant sticker on it, only on a couple I saw the toxic sticker.

Anyway - I always liken to think - if you can smell it, what do you think the concentration will be? femtomolar per litre of air? Probably less. Not even the most toxic compounds on earth are that toxic. Rule of thumb- as soon as you can smell it, hold your breath and move away.
You know, people get so stressed about solvents, but they are very happy to forget (or to remain ignorant) that normal petrol contains a significant proportion of BENZENE, which people handle every day, and noone gives a shit about. And benzene is a carcinogen, DMF clearly isn't. It's all relative.

Aromatics

chloric1 - 8-7-2005 at 17:06

Off subject here but chemleo, at least in the USA, they really cracked down on aromatics in gasoline. I know this is a fact becuase back in the 90's I could distinctivly make out a benzene odor especially on the hottest days. During the winter it was treated with low boiling alkanes for that little boost. Now the gas pretty much smells of alkanes all the time and it does not turn my stomach anymore either. Alot cleaner smelling brew these days.

IrC - 8-7-2005 at 17:50

"IrC, it isn't THAT dangerous, there are far more dangerous ones."

No doubt, and it has a low acute toxicity. It is what it does with chronic exposure that I refer to, having suffered liver problems do to it years ago. I usually tend to rag about something which has done me harm more that those things I merely read about. It can fool you into thinking it is not that bad while working with it, and then one day you are spending serious money at doctors with weird conflicting symptoms which the doctors cannot seem to figure out. Very much exposure to this stuff ends up giving you a liver similar to a veteran alcoholic. As to smell versus toxicity, some things I would fear to go by, such as H2S, which can sneak up and kill you while you think you are still safe. Other than that, sometimes if I perceive a person seems to be inexperienced I will usually try to warn them sternly, hoping it will cause them to think and research before they go and play with it.

"Anyway - I always liken to think - if you can smell it, what do you think the concentration will be? femtomolar per litre of air? Probably less. Not even the most toxic compounds on earth are that toxic. Rule of thumb- as soon as you can smell it, hold your breath and move away."

There are some exceptions to this, as in the H2S I mentioned, where if you suddenly find yourself in a 600 ppm area it will deaden your sense of smell, that is how the poison wells in S.A. take out oil workers. Likewise HCN and Phosgene will deaden your smell and taste receptors, and for Phosgene the toxic limit is lower than the odor threshold. So I over many years have always taken a better safe than sorry stance. In a gold recovery plant there was a vat 30 feet long and 5 feet wide full of cyanide, thalium salts, and other things, where the room was sealed off with a sliding door and a lone man in there in regular street clothes with no breathing equipment at all. Around 5 times a year he would be rushed to the hospital after using the CN kits onsite. He used to brag about his ability to tolerate it. The room itself had an air system and still the water cooler in the break room would always turn golden yellow before a third of the crystal water jug was used up.

The whole building always smelled like almonds except in the vat room where you never noticed any smell at all. Strangely enough the coffee made from that water cooler was the best tasting I ever drank.

[Edited on 9-7-2005 by IrC]

Chris The Great - 9-7-2005 at 18:05

Rhodium had some easy synthesis for DMF using simple chemicals as well. Alot easier than that patent using CO, and making methylamines etc.

Formic acid is nuetralized by dimethylamine to form dimethylamine formate. Dimethylamine is made by reacting hexamine, hydrochloric acid and formaldehyde in the right proportions. There is also a synth for this on rohodium. The dimethylamine formate is then refluxed at 95*C for 3 hours, during which it gives off a molecule of water and forms DMF in a 73% yield. They are then seperated. I'm sure you can find a rhodium backup somewhere on the web, the process is more accuratly described in the document titled "Amides from Carboxylic Acids and Amines".

I'm going to try it when I get some dimethylamine and formic acid made. I always thought it was a cool solvent, and of course it appears to be easier than DMSO.

Oh, always look up MSDS data before you make something. I am planning to make POCl3 this summer and I am extremely glad I read the sigma MSDS which mentioned it was lethal by inhalation at 35-50ppm. That would not be my idea of a nice surprise!

Also, why are halogenated hydrocarbons listed under incompatibles for DMF? There doesn't seem to be a reason why they would react....

greenyppols - 9-7-2005 at 21:59

1st, Irc I apologize for..uhm..venting on you. I woke up on the wrong side of the bed.
Chris the Great, Thanks. I have a few more good leads now.

And this is off subject too I guess. I can understand why everyone is tight lipped with a "go find out yourself" attitude, nevermind the general "attitude" lol. Just when I think I've acquired whatever I think is needed, WHAM, something pops up. SOMEthing to be overcome. Or just something thats gonna cost..which puts in the back burner. And after being in "acquistion mode" for the last few months..spending mucho dinero on various gizmos and contraptions and "stuff" to make "more stuff", if I ever figure this "stuff" out...I ain't tellin' NoBody Nuthin'. Go find out will be my attitude too. I figure this tends to weed out the dumb ones. hehehehe. Maybe me, who knows.

Anyway..enough rambling, and thanks.

IrC - 9-7-2005 at 22:53

Didn't bother me. I believe the more research you do on your own the more you learn, which usually makes whatever you do safer in the end. Besides, I always end up finding other things along the way to learn which are interesting. I can hear +Fravia bitching at me now for not paying attention the the prime directive of searching, stay tightly on track. I try, but there is so much other interesting stuff to learn along the way. In any case, the better you get at research on your own the better you get at whatever it is you are doing. And you are right, best to weed out the real lazy and/or real lamerz, better for them, better for all of us. Besides, I really did suffer a year or three with liver problems over that damn solvent, and I wanted to make you learn much about it before you played around. I have been trashed by some of the worst of the worst chemicals in over 50 years and it has taught me caution (as well as made me bitchy from time to time).

12AX7 - 10-7-2005 at 03:49

Quote:
Originally posted by IrC
Besides, I always end up finding other things along the way to learn which are interesting. I can hear +Fravia bitching at me now for not paying attention the the prime directive of searching, stay tightly on track.


I don't know who the heck Fravia is, but he must be thick. I've found lots of random, useful information unreleated to my searches :) For example, did you know aluminum can be MIG welded to steel? :P

Tim

[Edited on 7-10-2005 by 12AX7]