My 3-CMC synthesis

[draconic123]

Why does my 3 cmc oil turn black during acidification? i get it exactly 5.5-6 and it turns black

 

[Jesse_Pinkman_]

Maybe drop acid too fast...better cool the rm and the acid. Do you acidify the organic layer or with water together?

 

[draconic123]

only the organic layer, yes i suspect i acidify too fast.

 

[UWe9o12jkied91d]

haloketone turn black with acid, check reaction parameters

 

[Jesse_Pinkman_]

Put same amount dest.water into rm, then acidificaction drop by drop slowly, then take water layer to evaporate

 

[xoxoxoxo]

you get visible layers of water and freebase after adding acid??

 

[Jesse_Pinkman_]

Yes, and after that, take the upper layer, bottom layer will be disposed.

 

[Jesse_Pinkman_]

If dcm is used, when ethylacetate is used you take the bottom/water layer

 

[draconic123]

I only get whole black liquid with no layers

 

[UWe9o12jkied91d]

He means IF you add water.

 

[Jesse_Pinkman_]

Then you do something wrong i think...would you like to describe your steps of your synthesis?

 

[draconic123]

I carried out methylamination by leaving 2b3c dcm and methylamine for 12 hours no heat just stirring, disposed of top layer, washed bottom layer 2 times, disposed of top layer, added acid till 6, and the liquid became very dark red.

 

[UWe9o12jkied91d]

procedure sounds good, drip slower with good stirring
also be patient with just DCM, sometimes it decides to crash out in 2 min, sometimes it needs an hour stirring, acetone will help here I advise to use it (cold if poss.)

 

[draconic123]

i also forgot to mention that i used 10/100ml mix of hcl 36% and acetone to acidify i guess its either acetone or me adding acid to quickly... because at first it had rather nice color then went dark all of a sudden

 

[Jesse_Pinkman_]

I do not use acetone/hci mix, just 37% from freezer with dripping funnel, every 2-3 seconds 1drop...maybe you try this way one time

 

[UWe9o12jkied91d]

dcm only or with acetone?

 

[Jesse_Pinkman_]

As solvent for 2b3c i used dcm or ethylacetate, i tried both with similar results...

 

[UWe9o12jkied91d]

i meant for precipitation

 

[Jesse_Pinkman_]

I dont know what you mean? Which precipitation?

 

[draconic123]

Ok I know its dumb, however just to be clear, so after acidification you take top layer or bottom layer to dry using dcm? Im confused

 

[Jesse_Pinkman_]

I
only water layer