Author Topic: Short Questions Thread (Read 10831 times)

dingbow · « **Reply #1100 on:** December 11, 2011, 03:07:40 AM »

What overall length of column are you trying to achieve oldguy? Too long and heat loss is considerable and will lengthen distillation time, which in the case of certain ketones is not desirable as far as yields go. Personally I wouldnt use more then one column.

Dr. Tox · « **Reply #1101 on:** December 11, 2011, 03:45:27 AM »

Do you not have a vacuum? If so, what's wrong with a straight up west condenser?

newbiechem · « **Reply #1102 on:** December 12, 2011, 02:58:34 AM »

hey there everyone!

i wonder if anyone has any experience with a Sodium borohydride reduction, with amonium acetate? to get MDA.

process like one stated on rhodium. by labtop

i need nh3 gas or can i dissolve the AA in cold methanol, since it melta at low temp.
sorry my ignorance.

if anyone could clear up a couple things, would be a nice christmas present

peace!

Dr. Tox · « **Reply #1103 on:** December 12, 2011, 03:31:27 PM »

So... you have a basic solution of amines in IPA? Acidify to neutral and evap?

RoidRage · « **Reply #1104 on:** December 12, 2011, 04:21:36 PM »

I would favor using HCl (if you can get it !) over H2SO4 if you plans on using this ''titration'' method though. The product tends to scorch when excess HCl is present when evaporating, so It's probably even worse with sulfuric acid

.

Dr. Tox · « **Reply #1105 on:** December 12, 2011, 04:50:07 PM »

Also, excess HCl can evaporate, excess H2SO4 cannot....

RoidRage · « **Reply #1106 on:** December 12, 2011, 05:56:02 PM »

Quote from: Dr. Tox on December 12, 2011, 04:50:07 PM

Also, excess HCl can evaporate, excess H2SO4 cannot....

Thanks you for the clarification. As funny as it is, I've never really worked with H2SO4

Reckless: Any reason why you're not distilling the freebase ?

oldguy · « **Reply #1107 on:** December 13, 2011, 02:56:06 AM »

Dingbow and Dr. Tox,

Thanks much. I've seen meter-plus columns, but wasn't sure what problems they might introduce on a relatively small scale.

My friend is planning to use vacuum. A West condenser could be used, but my understanding is that a vacuum jacket provides better insulation than an air jacket, with silvered vacuum jackets being preferred above 100C (assuming one isn't heating the column to within a degree or two of the distillate temperature). Plus a Vigreux has a little better efficiency than a straight tube.

newbiechem · « **Reply #1108 on:** December 13, 2011, 04:59:30 AM »

not one infoon the borohydrate reduction with AA?

dingbow · « **Reply #1109 on:** December 13, 2011, 01:22:45 PM »

oldguy, imo careful temperature control is more important then the use of columns for distillation. I rarely use them, but if you really need one, a single column should suffice. Normally some sort of thermal insulation is wrapped around it, though this may not be required for ones that have a jacket under vacuum.

lugh · « **Reply #1110 on:** December 13, 2011, 03:55:33 PM »

The attached excerpt from a thesis by Ivar J. Halvorsen and Sigurd Skogestad was accepted for publication in the Encyclopedia of Separation Science

The number of theoretical plates needed for a separation is related to the difference in the boiling points and structure of the compounds involved

dream0n · « **Reply #1111 on:** December 30, 2011, 03:01:49 AM »

Looking at structures in Isomerdesign: Are the orientations used in the pictures , the assumed orientation, or is there proofing behind it? - likely done by Dr. Nichols for the particular compound I have found interesting.
This matters when concerned with drug design to achieve specific pharmacologic effects.
NBOMe compounds in particular.

blackr · « **Reply #1112 on:** January 23, 2012, 02:35:07 AM »

Quote from: lugh on May 17, 2011, 07:19:40 PM

sunlight
(Hive Bee)
04-09-01 04:50
No 183054
Re: How would correctly crystallize w. H2SO4 ?

A very easy way is to take your extractions of the base in ether or toluene, then add IPA/H2SO4 1:10 v/v slowly while swuirling, and check pH till 5-6, let cool, filter and wash with acetone a few times to remove the little excess of H2SO4 (it would decompose your salt with the time). That's all.
If you get a red layer at the bottom (some watter, salt and H2SO4) you need to add acetone to put all in solution and release your crystals.

The end results from the effort applied

Should be IPA:H2SO4 10:1 v/v. Definitely don't want to overdue it with the H2SO4

zgoat65 · « **Reply #1113 on:** January 28, 2012, 04:07:46 AM »

In the synth for benzyl chloride by doucherman, it. says to use a 600w halogen lamp with the uv screen removed. Is this because the uv rays affect the reaction? If so, could a high powered uv flashlight (the kind used to detect flourescent dye in refrigeration systems) be used instead. I known that the concentration of uv rays from this source is greater, and the heat produced by it. is significantly less making it. less of a fire hazard.

Assyl Fartrate · « **Reply #1114 on:** January 28, 2012, 10:32:55 AM »

How are we to know what synth you're talking about? Post a link or at least quote it.

You do need UV light if you're chlorinating toluene, it's a radical reaction. You could also use a tad of organic peroxides in there if you have some balls... and want to lose them...

That route is a mess anyway. Lots of hazardous, corrosive colored gas with a powerful odor, refluxing solvents, strong UV light, lachrymator fumes in huge quantities... only to get a mix of PhCH3, PhCl2H, PhClH2, and PhCl3... very hard to separate... just get some benzyl alcohol and heat it with HCl. Cheap, and you get quantitative yields.

Beware. Benzyl chloride is extremely irritating to the eyes and lungs. If you've never worked with lachrymators, you can't even imagine just how little is required to make your eyes feel both on fire and full of sand. You could find yourself clawing said eyes out and jumping out a 3rd floor window in search of relief if you don't handle ventilation VERY well. If you can smell any chemical in your lab when working with it in your ventilated space, you will be in a great deal of pain should you choose to produce benzyl chloride, even if you're wearing "air tight" goggles and a respirator from Home Depot.

Oerlikon · « **Reply #1115 on:** February 01, 2012, 03:41:08 PM »

I got some weird shit going on abotu my ketone and I will need your help...
Just distilled new batch of wacker MDP2P extracted with xylene like I many times before.
I had a HUGHE probelms with foaming and the fact that damn ketone started to come in very low temp ajnd very prue form as emolsuion and foam
(it never happened before with xylene,onyl with toluene and DCM) scorched some but finally menaged to get it.
There were no sharp fraction like usual and last 50ml or so of mine ketone came out BROWN so mine last (and purest) fraction is now brown!
To make it worst it REEKS on acid badly and crated a lot of aerosol when exposed to lower pressure and moisture.
I put a drop of ketone on pH paper,shown red,but since those things are unrealible for media w/o water I added a
drop of water and it instantly changed to neutral and ketone went green/yellow.

Repeating what I did on small scale I did on the whole last fraction,added some water...
No,it didn't helped completly to change color to normal but looks like acid smell si gone,I just feel like a complete moron
since I made an emulsion! Now I am drying it with some Na2SO4 and since it doesn't help much I will probably have to
decant it,wash the Na2SO4 with soem solvent to get all the ketone and evaporate the water and solvent under reduced pressure later.
I was thinking that acetone might be the best solvent here (ketone in ketone),right?!

Does anyone know why this happened!? Any advices what to do here?!

Happyman · « **Reply #1116 on:** February 02, 2012, 12:48:38 AM »

Quote from: Goldmember on November 17, 2011, 06:14:38 AM

Any suggestion on what one could do with a shitload of 5,5-dimethylhydantoin?
I had an idea for a use for it ages ago but that brainwave escapes me(coke analogue synth` perhaps?). $:-\$
Im thinking n condensation ,along the lines of Benzylhydantoin / Phe-hydantoin etc, but unless I can come up with some wizz-bang ring opening ,"hey presto and now its drugs", this wasnt my original thought and is quite boring really.

This shit is building up and she would really like to put it to good use.

Please all and any suggestions welcome. No spoon feeding required just a hint will do.

What about rehalogenating it?

newbiechem · « **Reply #1117 on:** February 11, 2012, 04:30:30 AM »

Quick question....

When letting a hgcl2/meoh solution stirring, with a condenser on top, and leave it stirring like overnight, could be any dangerous with hg vapors of any kind?
Also at a hg/al is there any dangerous mercury vapors?
Thanks

If one chose to test an area for hg vapors, drying the filter strip with the 1% pdcl2 solution must be done at a dissector? Or can be done at other room? Just to avoid contamination?
Peace

Sedit · « **Reply #1118 on:** February 11, 2012, 11:33:48 PM »

I would not be overly concerned with Mercury contamination under those conditions even though I have shown that evaporation of an HgCl solution allows for sublimation to occur. The fact that you are dealing with reflux means that most if not all of any vapors will be contained and remain in solution as long as the solvent levels remain high enough to assure complete dissolution.

Sedit · « **Reply #1119 on:** February 11, 2012, 11:42:10 PM »

Quote from: Oerlikon on February 01, 2012, 03:41:08 PM

I got some weird shit going on abotu my ketone and I will need your help...
Just distilled new batch of wacker MDP2P extracted with xylene like I many times before.
I had a HUGHE probelms with foaming and the fact that damn ketone started to come in very low temp ajnd very prue form as emolsuion and foam
(it never happened before with xylene,onyl with toluene and DCM) scorched some but finally menaged to get it.
There were no sharp fraction like usual and last 50ml or so of mine ketone came out BROWN so mine last (and purest) fraction is now brown!
To make it worst it REEKS on acid badly and crated a lot of aerosol when exposed to lower pressure and moisture.
I put a drop of ketone on pH paper,shown red,but since those things are unrealible for media w/o water I added a
drop of water and it instantly changed to neutral and ketone went green/yellow.

Repeating what I did on small scale I did on the whole last fraction,added some water...
No,it didn't helped completly to change color to normal but looks like acid smell si gone,I just feel like a complete moron
since I made an emulsion! Now I am drying it with some Na2SO4 and since it doesn't help much I will probably have to
decant it,wash the Na2SO4 with soem solvent to get all the ketone and evaporate the water and solvent under reduced pressure later.
I was thinking that acetone might be the best solvent here (ketone in ketone),right?!

Does anyone know why this happened!? Any advices what to do here?!

Please clarify as I have a very hard time understanding what you are attempting to accomplish or exactly what is going on. Why do you want to use Acetone and what is it for?

If you have acidic ketone then obviously you need to perform a few simple water washes to remove any contamination.

There is no way your purest fraction is the brown fraction and if that's the case then you are dealing with a very dirty mixture that needs serious purification. I suggest brine washes followed with a Sodium Bisulfate wash... Keep the (aq) layer and wash this with a non-polar solvent repeatedly before freeing your ketone from its adduct at which point you can exact it with Dichloromethane.

I am a huge fan of Dichloromethane and I suggest this as the main solvent for use in many of the steps needed in purification and synthesis of MDMA.

Author Topic: Short Questions Thread (Read 10831 times)

dingbow

Re: Short Questions Thread

Dr. Tox

Re: Short Questions Thread

newbiechem

Re: Short Questions Thread

Dr. Tox

Re: Short Questions Thread

RoidRage

Re: Short Questions Thread

Dr. Tox

Re: Short Questions Thread

RoidRage

Re: Short Questions Thread

oldguy

Re: Short Questions Thread

newbiechem

Re: Short Questions Thread

dingbow

Re: Short Questions Thread

lugh

Re: Short Questions Thread

dream0n

Re: Short Questions Thread

blackr

Re: Short Questions Thread

zgoat65

Re: Short Questions Thread

Assyl Fartrate

Re: Short Questions Thread

Oerlikon

Re: Short Questions Thread

Happyman

Re: Short Questions Thread

newbiechem

Re: Short Questions Thread

Sedit

Re: Short Questions Thread

Sedit

Re: Short Questions Thread