Lepa in učinkovita pot za lastno sintezo 2b4m (povprečno 50 ameriških dolarjev za kg)

[Dr. MMX]

Hej, jaz bom samo vnesel reagente, ki jih uporablja pametna izbira (cena/napor), ki jih je mogoče kupiti v Evropi
torej 1.
PCL5 z elementarnim žveplom > tionilklorid

tionilklorid + propionska kislina > priopionilklorid

sinteza 4mp (tukaj je tema, zato bom samo povezal):
propionil klorid
Toluen
brezvodni AlCl3

http://bbzzzsvqcrqtki6umym6itiixfhni37ybtt7mkbjyxn2pgllzxf2qgyd.onion/en/threads/synthesis-of-4-methylpropiophenone-from-toluene-by-friedel-crafts-reaction-1kg-scale.209/

nekaterepleksne težave z bromiranjem
žveplova kislina, ki je potrebna za pridobitev Hbr, ki je nekoliko draga in ni pogosto na voljo. Namesto tega uporabimo:
fosforno kislino in NaBh za reakcijo > dobimo HBR
H2O2 12 % lahko kupimo in destiliramo do nekaj več %, na primer 25-30 %.

Torej
4 metilopropion + HBR + H2O2 > 2b4m

nisem izračunal stroškov, vendar so zelo majhni in ni treba čakati na pošiljko ali biti presenečen nad nizko kakovostjo predhodnika

 

[chost]

ali lahko podrobneje razložite, kako izdelati HBR?

 

[Dr. MMX]

O, res mi je žal, da sem se zmotila. pravilno je:
Za proizvodnjo hidrobromne kisline (HBr) iz fosforne kisline (H₃PO₄) in natrijevega bromida (NaBr) lahko uporabite reakcijo dvojnega izpodrivanja. Reakcijo lahko predstavimo na naslednji način:

1. Reaktanti: Fosforna kislina (H₃PO₄) in natrijev bromid (NaBr).
2. Produkti: Vodikrobromna kislina (HBr) in natrijev fosfat (Na₃PO₄).

Uravnotežena kemijska enačba za reakcijo je:


H3PO4+3NaBr→3HBr+Na3PO4


Pri tej reakciji fosforjeva kislina reagira z natrijevim bromidom, pri čemer nastaneta hidrobromna kislina in natrijev fosfat.

 

[chost]

Ali je destilacija potrebna?
In v kolikšni količini vode naj raztopim natrijev bromid?

 

[Dr. MMX]

Kako drugače nameravate dobiti stvar, ki je v osnovi plin?

Odvisno je, kakšen % želite imeti, največ je 47 %, kot se spomnim, in to bi moralo biti že tako

 

[Benz88]

is it Safe to Distille the h2o2 to maybe 30-35% from 12%?

 

[TheVacuumGuy]

H3po4 z NaBr za nastanek HBr? To bom poskusil v eni minuti.

Imam veliko HBr, vendar me zanima, ali bosta reagirala.

 

[Dr. MMX]

da in Na3PO4

 

[Dr. MMX]

To je čudovito

 

[TheVacuumGuy]

Didn't work. I think it would be easier to add sulfuric acid to a solution of KBr (or NaBr) , which would readily yield HBr at 125c

 

[Dr. MMX]

I tried to override having sulfuric acid becasue here is troubles to get it. It was very extreme attempt
if there is access to sulfuric acid its easy job

 

[Dr. MMX]

you can get elemental bromine from potasium bromide, dont need to use acids.
it was quite cheap as i remember

 

[Toddler]

Hbr2 48% can work ?
(CAS.No: 10035-10-6)

how much ration use for bromination
Hbr2
H2O2
for 100g of 4MPP

 

[TheVacuumGuy]

Roughly,

H2o2 50ml
HBr 100ml

 

[Toddler]

for 100g of 4MPP

 

[w2x3f5]

Instead of propionyl chloride, can use propionic anhydride (obtain phosphorus oxide from propionic acid), can also use propionic acid directly with polyphosphoric acid (there are many options for this reaction, you can choose the best one). If propionyl chloride is used with anhydrous aluminum chloride (can be replaced with cheaper and simpler options). Then it is best to carry out a bromination reaction before hydrolysis in Fridel-Crafts (the complex of 2b4m and aluminum chloride is very active for bromination with a high yield).

 

[Dr. MMX]

In chemistry trade buissness in europe propionic acid is considered with "silent restriction" with reason it can be used as biological weapon, so should be avoided there.

very interesting choice of propionic anhydride

 

[Osmosis Vanderwaal]

@TheVacuumGuy you gave him bad figures and he used them and probably ruined 100G 2B4-MP. I dont know what he paid, but I got $200 all day for 10g if it's domestic . In th rules there are a few gold nuggets. "Use the fucking search engine." That's a rule. Another one is " a good chemist i an accurate chemist." Make sure that you clearly state you are guessing when you don't know. You could say nothing at all, you could show your math or you could tell him he needs to figure it himself, but please, dont just throw out random numbers, with no disclaimer.

 

[TheVacuumGuy]

Show me what's wrong then. I used these figures with success. note that hydrogen peroxide is a solution of 35%.

 

[TheVacuumGuy]

i stated roughly , not stoicimeticly

reactants	Coeff	Molar Mass	Moles (g/mol)	Weight (g)
C10H12O	1	148.20168	0,67	100
HBr	1	80.91194	0,67	54,595831842122166
H2O2	1	34.01468	0,67	22,951615663196257
products	1
C10H11BrO	1	227.09774	0.67	153,23560434672535
H2O	2	18.01528	1,35	24,311843158593074

HBr 48% = 8.77 mol/L => for required 0.67m corresponds to 0,0764L (76ml)
h2o2 35% = 11.63 mol/L => for required 0.67m corresponds to 0,0576L (57ml)

Yes that's a bit off from 100 and 50, but these numbers are theoretically, which almost never applies in practice. ( like a mephedrone synthesis is given methylamine x2 but theoretically only needs x1/5 )

furthermore excess reagents are neutralized afterwards.

 

[w2x3f5]

You have not taken into account the purity of precursors, at the end of the reaction you will not have acid. No acid = no protonation

 

[TheVacuumGuy]

.