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Author: Subject: The Short Questions Thread (4)
solo
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[*] posted on 9-12-2022 at 19:01


....original post was deleted

[Edited on 10-12-2022 by solo]




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[*] posted on 9-12-2022 at 20:32


Please comment on... MDP2P

By all means discuss the chemistry. But don't let it turn into something that will spoonfeed a procedure to some kewl whose only interest is class A drugs.
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[*] posted on 15-12-2022 at 02:36


I have a procedure that calls for drying bromonitromethane dissolved in dichloromethane over sodium sulfate prior to evaporating the dichloromethane. Can I substitute the sodium sulfate for calcium chloride? Obviously sodium sulfate is easily obtained, I just don't have any on hand right now and am eager to get started.
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[*] posted on 24-1-2023 at 11:17


........not having any resuts looking for CuNiAlx catalysst, would like some help on its preparation or who sell it....solo



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[*] posted on 24-1-2023 at 16:47


Quote: Originally posted by B(a)P  
I have a procedure that calls for drying bromonitromethane dissolved in dichloromethane over sodium sulfate prior to evaporating the dichloromethane. Can I substitute the sodium sulfate for calcium chloride? Obviously sodium sulfate is easily obtained, I just don't have any on hand right now and am eager to get started.


Don't see any reason CaCl2 would not work well, it is not basic or reactive with that, as best as I can see. DCM should be fine as well. Good luck.
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[*] posted on 31-1-2023 at 11:34



What is in Bakers No. 3 flux for soft soldering.
There is zinc chloride, anything else? and how much?

Cheers.
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[*] posted on 31-1-2023 at 11:53


Quote: Originally posted by yobbo II  

What is in Bakers No. 3 flux for soft soldering.
There is zinc chloride, anything else? and how much?

Cheers.


Ammonium chloride

Attachment: 564987s_v1.pdf (348kB)
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[*] posted on 2-2-2023 at 08:28



Thanks B(a)P,

Before I read the post I decided to make some myself. (Did not know it contained Ammonium Chloride).
Added some Zinc Chloride to water and a sup of HCl acid. The stuff works great. Far better than the paste type flux.
The paste type is probably far less corrosive etc, for electrics, but I am doing big rough stuff.

Cheers,
Yob
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[*] posted on 3-2-2023 at 06:04


Quote: Originally posted by solo  
........not having any resuts looking for CuNiAlx catalysst, would like some help on its preparation or who sell it....solo


...found the information....

Catalyst preparation.
CuNiAlOx was prepared by the coprecipi-tation method. 1.44 g (5.96 mmol) of Cu(NO 3 ) 2·3H 2 O, 3.48 g (11.97
mol) of Ni(NO 3 )2·6H 2 O, and 6 g (15.99 mmol) of Al(NO 3 ) 3·9H2 Owere added into 150 mL of deionized water at 80 °C in a 250 mL flask,and under vigorous stirring, 60 mL of Na2 CO3 solution (1.415 mol)was added dropwise into the solution. The mixture was mechanically stirred for 5 h and then cooled to room temperature and filtrated.

Following, the filtrate was washed with deionized water to neutral,
dried at 100 °C for 5 h, calcined at 400 °C for 4 h, and then reducedunder hydrogen flow at 450 °C for 2 h. Finally, the obtained catalystwas denoted as CuNiAlOx. The catalysts denoted as CuAlOx, NiAlOx,and CuNiOx were prepared with the same procedure

......Sustainable Catalytic Amination of Diols: From Cycloamination to
Monoamination --Yajuan Wu




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[*] posted on 14-2-2023 at 14:14


Is it generally safe to use allihn condensers and vigreux columns under vacuum? Esp for vigreux, all the little indents make me think twice, but given the size of each hole is small...
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[*] posted on 20-2-2023 at 17:52


Might someone know what these "natural lava stones" are made of and what makes them a bit pricey. They mention calcium. Perhaps they take a lot of heat to make as one reason for cost?

Hamster Chew Toy Lava Teeth Grinding Square Stone For Hamsters Chinchillas and Rabbits Mineral Stone
https://youtu.be/YTbHAg4aLhw

Another aspect is they don't crumble or become friable when heated like some "pumice stones" I have cracked when hitting them with a torch.
https://youtu.be/RET638sfKNk
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[*] posted on 20-2-2023 at 20:00


i want to tosylate the Oh function of a carboxylic acid, but don't know if the conditions for the process is the same as for alcohols, perhaps with its not the same....i've looked but have not found anything specific on the procedure if its possible.....solo


...at the end i want to substitute the totsyl wih CN. or is there a direct way to add the CN to the carboxyic acid OH position?

[Edited on 21-2-2023 by solo]




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[*] posted on 21-2-2023 at 08:49


the goal is to make a ketone from an existing carboxylic acid, but maybe if i use acetic acid and tosylate the OH and substitute with a halogen ...giving me a acid choride that i can easiy use to acylate the benzene ring....solo



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[*] posted on 21-2-2023 at 10:53


It's not exactly the same. Tosylated alcohols are tosylate esters, while a tosylated carboxylic acid would effectively be a mixed anhydride, so much more labile. Based on a quick literature search though, it appears that benzoyl tosylate has been prepared in moderate yield either from benzoyl chloride and silver tosylate in acetonitrile (which would of course defeat your purpose since you are after the acyl chloride, and the stoichiometric silver is rough too), from tosyl chloride and sodium benzoate with a phase transfer catalyst in DCM, or from tosyl chloride and benzoic acid with triethylamine as a proton scavenger in acetone. The latter sounds the most promising, if you have tosyl chloride available.

Edit: just noticed it sounds like you're after the acetic-tosylic anhydride, which apparently can be prepared by the same methods I described above, or alternately from acetic anhydride and tosylic acid in toluene at reflux. Seems like a rather roundabout way of making acetyl chloride, and it depends on you having access to acetic anhydride or tosyl chloride, both of which may be just as hard or harder to acquire.

[Edited on 2-21-2023 by Texium]




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[*] posted on 21-2-2023 at 13:24


....thanks for the input, but my goal is the 4 amino acetophenone, i tried the claisen condensation....its just to delicate and just gave up on it and i have no access to acid chloride to acylate hence i chosen to go around and tosylate the carboxyic acid then swap with CN with (NaCN) and reduce to an amine with NaBH4/I in THF ...thereby acquireing the ketone and and amine which i will use to hang tert butylbromide....the end goal is clenbuterol ......solo

[Edited on 21-2-2023 by solo]




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[*] posted on 22-2-2023 at 05:24



Is there a difference in the boiling points of Silicone oils of different viscosities?

Silicone Oil 50 cPs (Polydimethylsiloxane PDMS) - Dimethicone 50
and
Silicone Oil 350 cPs

which would be the best for a diffusion pump?

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[*] posted on 26-2-2023 at 17:09



The Silione 350cPs has a boiling temperature of >315C

Yob

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[*] posted on 26-2-2023 at 17:10



What % approx. of Barium Carbonate would be in rat poison (assuming the rat poison contains BaCarb)?
I was going to make some.
The wax blocks are only fattening the rats around here!

Yob
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[*] posted on 6-3-2023 at 08:09


Breaking hot update on the rat poison................

I made some rat poisong using barium perchlorate (somewhere between 10 and 20%).
I was thinking that the perchlorate would be too unpalatable and that obtaing carbonate would give a more palatable feed.
The rats did not appear to be eating the stuff. I had also mixed some icing sugar with the meal and perk. to try and sweetin things.
Only small amounts of the meal (poison) disappeared but the rats are all gone!
The stuff appeares to be lethal and edible.

Yob
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[*] posted on 23-3-2023 at 07:26



Can anyone suggest a heat sink compound for a very high temperature. It has to work at 320C to perhaps 360C.
It is between two stainless steel surfaces.

Cheers,

Yob
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[*] posted on 23-3-2023 at 08:11


For easy to apply and moderately safe, I've had good experiences using
boron nitride based thermal paste. It dries hard and can be difficult to separate the parts.
The dust is also dangerous. It is electricly non conductive, chemically resistant. And not to expensive.
Some places sell 5cc for 10~20 usd, as a therm paste for cpu/gpu whish soft sets. The cheaper
Kind sets hard and is much cheaper. 500g for $25 last time I restocked.

Depends on what other specs you have.
That tempature range will ware out normal paste like materials.
Paste rated for the tempature range have lower conductivity values
usually below 40 W/mK

Soft metals are the way to go, requiring a pressure fit. Giving the best
thermal conductivity possible. Over 400W/mK depending on the metal used.

If you do not care about electrical or magnetic characteristics
then a wide range of materials will work.

If the parts will not be seperated under normal conditions,
a high temperature solder would work great, but then their stuck together.
Application will be difficult to.





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[*] posted on 23-3-2023 at 11:08



It does not matter if the paste is electrically conductive or not. Magnetic properties are irrelevent.

I was thinking copper paste.
If I obtained something like this:
https://www.ebay.co.uk/itm/171155282670?hash=item27d9a65aee:...

Burned out all the organics at 400C (under argon ) and I would be lift with copper powder.
I could just buy copper powder.

I will be lapping the surfaces. Total area is about 100 square cm

Yob

[Edited on 23-3-2023 by yobbo II]

[Edited on 23-3-2023 by yobbo II]
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[*] posted on 23-3-2023 at 12:36


That product is a high heat lubricant, dought it will have many organics if any. Likely clay/silicone oil with copper filler.
You can use annealed copper foil, will be same price and less work





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[*] posted on 8-4-2023 at 12:26
Auto brake cleaner solvent


I'm after some cheap non-polar solvent for some oil extraction and bought some brake cleaner last week.

It contains n-alkanes and isoalkanes as main constituents.

If I distil this would it be a useful solvent?
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[*] posted on 8-4-2023 at 13:34


Assuming it doesn’t contain other volatile components that are problematic, that sounds good. Depending on what range of alkanes are in it you may even be able to fractionate it into portions with different boiling ranges. Also look for “non-flammable” brake parts cleaner. It is usually pure tetrachloroethylene. It seems to be getting more difficult to find, though.



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