Pěkná a účinná cesta pro vlastní syntézu 2b4m (avg 50 usd a kg)

[Dr. MMX]

Ahoj, napíšu jen reagencie používané moudrým výběrem (cena/náročnost), které se dají koupit v Evropě.
takže 1.
PCL5 s elementární sírou > thionylchlorid

thionylchlorid + kyselina propionová > priopionyklchlorid

Syntéza 4mp (zde je téma, takže jen odkaz):
Propionylchlorid
Toluen
AlCl3 bezvodý

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

některépplechovky mají problém s bromováním
Kyselina sírová, která je nutná k získání Hbr, je trochu drahá a není často k dispozici. Místo toho používáme:
K reakci použijeme kyselinu fosforečnou a NaBh > získáme HBR.
H2O2 12 % lze koupit a vydestilovat na více %, například 25-30 %.

takže
4 methylopropion + HBR + h2o2 > 2b4m

Náklady jsem nepočítal, ale jsou velmi malé a není třeba čekat na dodávku nebo se podivovat nad nízkou kvalitou prekurzoru.

 

[chost]

Můžete podrobněji vysvětlit, jak se vyrábí HBR?

 

[Dr. MMX]

Ach, opravdu se omlouvám, že jsem udělal chybu. je to správně:
K výrobě kyseliny hydrobromové (HBr) z kyseliny fosforečné (H₃PO₄) a bromidu sodného (NaBr) lze použít reakci dvojího vytěsnění. Reakci lze znázornit takto:

1. Reaktanty: Kyselina fosforečná (H₃PO₄) a bromid sodný (NaBr).
2. Produkty: Kyselina hydrobromová (HBr) a fosforečnan sodný (Na₃PO₄).

Vyvážená chemická rovnice pro tuto reakci je:


H3PO4+3NaBr→3HBr+Na3PO4


Při této reakci reaguje kyselina fosforečná s bromidem sodným za vzniku kyseliny hydrobromové a fosforečnanu sodného.

 

[chost]

Je nutná destilace?
A v jakém množství vody mám rozpustit bromid sodný?

 

[Dr. MMX]

Jak jinak chcete získat věc, která je v podstatě plyn?

Záleží na tom, jaká % chcete mít, max. je 47 %, pokud si vzpomínám, a to by mělo být už takto

 

[Benz88]

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

 

[TheVacuumGuy]

H3po4 s NaBr za vzniku HBr? Chystám se to za chvíli vyzkoušet.

Mám spoustu HBr, ale jen mě zajímá, jestli tyto dvě látky reagují.

 

[Dr. MMX]

ano a Na3PO4

 

[Dr. MMX]

To je úžasné

 

[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]

.