Sciencemadness Discussion Board
Not logged in [Login - Register]
Go To Bottom

Printable Version  
Author: Subject: Sandmeyer head aches
Babs
Harmless
*




Posts: 16
Registered: 28-7-2017
Member Is Offline


[*] posted on 10-11-2017 at 22:26
Sandmeyer head aches


Hi guys/gals

So he has been looking at turning an aliphatic amine to an OH group, replacing the amine, which I think is simply a SN2 reaction between OH2 and the positively charged, post reaction with thr nitrite salt under slightly acidic conditions, be it
(+) NN-(CH2)xC00H > HO(CH2)xCOOH + N2. The problem is excessive foaming, My friend always msg's me when stuck, so on a theoretic level, how can extreme foaming occur. He sent me a picture post slowly dripping in HCl solution, one drip per 8 - 10 seconds under rapid stirring, He said he was trying to reduce the amount of NO2(brownish gas from forming) so I asked

Did you get the pure amine, YEP he stated. Hmmm
Did you buy tech grade NaNO2, Absolutely AKA no fillers and anti clumping additives.
Did you add this to a bath predominantly of ICE, Yep, of course I did.
So to determine the amount of HCL, Did you use the Moles required times the MW of HCL then pending THE mass, dividing that bu the concentration, be it 0.32, YEP he said, then you divided that by the density of g/ml, absolutely he stated

So We talked about the mechanism and how it (If I am correct) eventually leads to an SN2 reaction between OH2 and the positively charged N2 group, bubbling off and that could result in excess bubbling but knuckhead, stated, post the addition of HCl there was two inches of foaming, which was removed, and the pot left to reach room temperature over night, and in the next morning, there was 3 inches of foaming.

Any clues, tips, abuse for being a dumbass, well all is welcome. As fAR as iM concerned the only real unknown is the concentration of HCL, hence a titration maybe the thing to do. My other thoughts is they have added a non polar molecule with a polar end, that could form miscells but Im not sure.

Advice and or help with this will be very much be appreciated. Ive asked KH to join this place, but he is a tad shy, especially with respect to chemistry. Rolls eyes repetivilly, as Ive learnt it more about the amounts of things you do have, than anything else, but hey, the Amanda Duncans of this world, can twist and slant it in anyway they want, so I get KHs reservations.

[Edited on 11-11-2017 by Babs]

[Edited on 11-11-2017 by Babs]
View user's profile View All Posts By User
Cryolite.
Hazard to Others
***




Posts: 172
Registered: 28-6-2016
Location: CA
Member Is Offline


[*] posted on 10-11-2017 at 23:40


Let me guess, your amine here is GABA?

Do you have any sort of experimental writeup indicating what exactly you did here?
View user's profile View All Posts By User
Babs
Harmless
*




Posts: 16
Registered: 28-7-2017
Member Is Offline


[*] posted on 11-11-2017 at 00:06


Well the ratio was 1:1:1.1 namely amine, NaNo2 and HCl, I was told he scaled this down to one mole of all the contributing molecules, but a mild increase in the HCl used, that being 1.1 moles.
The flask sat in an ice bath, that included CaCl2, and slowly dropping in the acid. He has done this before, and spun out about such frothing, which had not ever happened before, I posted this, just in case that slowing the reaction down, aka, one drop every 8 -10 sec0nds may cause some effect. Im personally at a loss.

Rapid stirring to

[Edited on 11-11-2017 by Babs]
View user's profile View All Posts By User
gdflp
Super Moderator
Thread Moved
11-11-2017 at 00:37
gdflp
Super Moderator
*******




Posts: 1297
Registered: 14-2-2014
Location: NY, USA
Member Is Offline

Mood: Staring at code

[*] posted on 11-11-2017 at 00:41


The SWIM tone of your post is not allowed and, frankly, it's not fooling anybody.

Your intentions are painfully obvious, and this type of discussion is not welcome on SciMad.

[Edited on 11-11-2017 by gdflp]




View user's profile View All Posts By User

  Go To Top