|
 the
Hive BB  Methods
Discourse  Bright
Star Al-Hg bad ending.
|
| next newest topic | next oldest topic |
| Author | Topic: Bright Star Al-Hg bad ending. |
| McDog unregistered |
posted 06-01-99 03:49 PM
My friend has twice dreamed the Bright Star recipe and each time it went fine until the end of the Al-Hg. Both times, this is what happened: He let the Al-sludge-ketone etc mixture stir for 9-10 hours till he was sure it was done, then added 25 ml of 25%NaOH. Let it stand 1/2 hr. Then added 25ml more NaOH. Then because there was no change in it, i.e. the sludge didn't fall out, he added another 100ml of NaOH. Still nothing happening so he added some IPA. He then poured the mix thru a strainer to strain out the bits of aluminum left. What was left was a black liquid. This is a mix of the original stuuf which should have at lwast 5-10 g of freebase in it, since it was done exactly as the Bright Star recipe (40g ketone and 50 g MeAm etc) So how can he recover the goods from this black liquid? It's a watery consistency. Adding more IPA or even a bit of DCM has no effect, it's miscible with them. He could vac distill off the extra water and IPA from it, but then thre'd be a lot of NaOH left behind with the honey. So can he get the honey out? Maybe he could add some HCl to it after vacuuming off the water and IPA and neutralize the NaOH? |
| Osmium Member |
posted 06-02-99 03:45 AM
Steep learning curve ahead for your friend, tell him next time he should understand the basics first before trying it. Black colour? This is strange. How did your friend purify the ketone? Ok, to save this run from going down the sink, try the following: |
| maryjo666 Member |
posted 06-13-99 04:48 PM
My friend's dream of the Bright Star method was going really well up to the last part...the Al-Hg part. It started off OK...exactly as in the recipe. 20 g Al, a smidgeon of HgCl2, wash out, then added 50g MeAm in 300 ml IPA and 40 g ketone in 50 ml IPA and then 25 ml 25%NaOH, then let stir 8 hr. After 8 hr. the sludge seemed to be drying up...it was no longer liquidy because most of the water seems to have evaporated. It was sort of a thick pasty consistency. Has anyone else had this problem? How can my friend get the freebase out of this thick paste- just start to add more IPA? |
| maryjo666 Member |
posted 06-13-99 05:28 PM
So anyway my friend proceeded with the Bright Star method...after adding 25ml NaOH she then added 200 ml IPA because it was pasty. She then strained the sludge through a strainer...and found that most of the aluminum hadn't reacted. It was not even thick foil but regular kitchen foil. This is so frustrating for her. The reaction had actually gone on for 10 hours, there should not be any foil left. The ketone had been carefully distilled. The MeAm was clean. What went wrong? |
| maryjo666 Member |
posted 06-13-99 05:57 PM
Here's 2 points she's pondering for the failure: 1. Maybe she didn't use enough HgCl2 at the beginning. She used one of those McDonald's Restaurant coffee stirsticks with the tiny spoon on the end to measure the HgCl2, using 2 tiny spoonfuls. That should be enough for 20 g Al. 2. The Bright Star method perhaps doesn't use enough of the 25% NaOH solution to get the MeAm-HCl reaction going. i.e. 25 ml of NaOH may not be enough, because in TS2 Strike uses a lot more NaOH solution in this reaction. Comments anyone. |
| Osmium Member |
posted 06-14-99 04:15 AM
Filter/decant away the solvent from the sludge, extract it several times with more solvent and work it up. Take care that all sludge is removed from the solvent, or you will learn the meaning of the word emulsion. You can't tell if it went wrong just by looking at the reaction. |
| maryjo666 Member |
posted 06-14-99 07:57 AM
There's got to be something wrong with Bright Star's Al-Hg recipe (as posted in the big post in the General Discourse). In the book T.S.2 Strike uses a whole shitload more NaOH solution for the Al-Hg part...186 ml NaOH for 67 g ketone. Bright Star only uses 25 ml NaOH for 40 g ketone. They can't both be right- there's too much discrepancy. I would tend to think one has to use quite a bit more NaOH solution in this recipe because the methylamine is not aqueous, it's MeAm HCl, so as I recall there was once a post somewhere that said when you use MeAm HCl you have to use a lot of NaOH to get it to react properly. So who will agree that the Bright Star needs more NaOH? |
| maryjo666 Member |
posted 06-14-99 08:02 AM
Oh- and 1 more thing that Bright Star should mention that I found in Strike's book- when you do the acid-base extracction at the end of the Al-Hg, and you add 500ml 0.5M HCl acid to the freebase liquid, then extract the crap out with DCM, Strike says save that DCM because there's probably some unreacted ketone in it. |
| Semtex
Enigma Member |
posted 06-14-99 10:02 PM
Ok first, don't question Bright Star, as the Bright one has probably done a battery of analytical tests on EVERY aspect of this. If Bright Star says there is nothing of any use, throw it out. Next SWIM(Someone Who Isn't Me) has noticed similar problem(s) with the ass end of the Al/Hg. When NaOH was added solution turned into a black single layer and after 36h+ standing no change was evedent. SWIM therefor surmises that if your having problems with that part, then vac filter the sludge instead(Strikey ala TS II) or I belive that Osmium suggest the best way to extract it too. Conclusion: When one speaks analytically, Bright Star is a god. When one wonders about the Al/Hg Osmium is Ala. But then again what the fuck do I know?
|
| Osmium Member |
posted 06-15-99 03:17 AM
Black colour after basification probably means that your ketone contains hydroquinone/benzoquinone from the last step. The hydroquinone is rapidly oxidised in strongly basic solution, producing the usual ugly black or brown colour typical for phenolic chemistry. Also use enough NaOH in the Al/Hg reaction to neutralise all the HCl from the MeNH2. This is a point where BS and O's opinions differ, but in my experiments all the MeNH2 used was in the form of 40% aq. solution. Calculate the necessary amount yourself. Adding excess NaOH causes higher reaction rate of the Al. Too much and it is likely that the whole thing will boil over, especially when using foil. So when you think the reaction is way too slow, add some more NaOH. |
| maryjo666 Member |
posted 06-15-99 07:34 AM
Thanks, Os. I didn't use the wacker anyway. I dreamed about the modified performic. The ketone was carefully distilled and was clear yellow. Anyway in my dream the sludge at the end of the Al was totally removed fairly easliy and quickly using 2 kitchen strainers- a coarse one and a small fine one. Then it was pretty easy to vac filter the rest of the sludge thru a buchner with a layer of thin kitchen sponge cut to fit well instead of using filter paper. Then what was left was a black watery liquid with a lot of NaOH and a lot of IPA. Then I made the next mistake- I dreamt I didn't vac distill enough of the liquid off. When I added the 0.5M HCl there was much too much IPA still there. Then when I basified with NaOH and added DCM, there was 3 layers- top, black watery IPA layer, middle, black DCM, and bottom, a huge clear layer of NaOH. So I decanted the black layers and I'll try to vac dist. off more IPA and water. |
| scwam Member |
posted 06-15-99 05:05 PM
I have a question a little off the topic but dont want to waste opening a new thread just for it. The first reaction I ran was just under 4.5 hours with a mixer/blender. The ending sludge was so finely chopped up that you could barely see little pieces of aluminum as very fine sparkles throughout the nice grey solution. I found it easy as hell to filter out the oil with this method as nothing was left (big aluminum chuncks). Would these be an undesirable way of doing the reaction since you got mechanical chopping of the aluminum fromt he sharp blades? It created a HELL of a STIRRING mechanism and didnt burn out the blender. Final result was somewhat active crystals with only 4.5 hours running. Could someone comment? |
| Semtex
Enigma Member |
posted 06-15-99 11:34 PM
Osmium: This maryjane person read SWIMS thoughts, the ketone was from a preformic rxn, bright yellow with the slightest hint of orange. The black stuph SWIM was reffering to was watery, not a sludge, fucked if I know. In my opinion it's better to filter the sludge off rather than adding a shitload of NaOH to seperate it. |
|
All times are CT (US) |
next newest topic | next oldest topic |
 
|
|
Contact Us | the Hive
Powered by: Ultimate Bulletin Board, Version 5.39a
© Infopop Corporation
(formerly Madrona Park, Inc.), 1998 -
1999.