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- Dec 17, 2023
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Hallo guys,
I also prefer method in DCM.
I mixed 100g of Bromketon in 300ml DCM and slowly added 200ml of Methylamin 40%a.q. solution.
Now my question, what temperature and what time would be the best.
Last time I kept temperature at 36 - 37 degrees and reaction-time was 3hours.
But the product was extremly blue after acification.
How can I repair the relation between temperature and cooking time best.
Smaller temperature = longer reaction time?
Which temperature are not working.
Can anybody help and explain the reasons of temperature and cooking time?
Thank you a lot.
I also prefer method in DCM.
I mixed 100g of Bromketon in 300ml DCM and slowly added 200ml of Methylamin 40%a.q. solution.
Now my question, what temperature and what time would be the best.
Last time I kept temperature at 36 - 37 degrees and reaction-time was 3hours.
But the product was extremly blue after acification.
How can I repair the relation between temperature and cooking time best.
Smaller temperature = longer reaction time?
Which temperature are not working.
Can anybody help and explain the reasons of temperature and cooking time?
Thank you a lot.
Hallo guys,
I also prefer method in DCM.
I mixed 100g of Bromketon in 300ml DCM and slowly added 200ml of Methylamin 40%a.q. solution.
Now my question, what temperature and what time would be the best.
Last time I kept temperature at 36 - 37 degrees and reaction-time was 3hours.
But the product was extremly blue after acification.
How can I repair the relation between temperature and cooking time best.
Smaller temperature = longer reaction time?
Which temperature are not working.
Can anybody help and explain the reasons of temperature and cooking time?
Thank you a lot.
You have a problem with bromoketone, most likely it is dirty. you need to watch its melting point and try to recrystallize the bromoketone, or you will have aniline homologues mixed with mmc
- Joined
- Sep 20, 2023
- Messages
- 101
- Reaction score
- 34
- Points
- 28
Hallo guys,
I also prefer method in DCM.
I mixed 100g of Bromketon in 300ml DCM and slowly added 200ml of Methylamin 40%a.q. solution.
Now my question, what temperature and what time would be the best.
Last time I kept temperature at 36 - 37 degrees and reaction-time was 3hours.
But the product was extremly blue after acification.
How can I repair the relation between temperature and cooking time best.
Smaller temperature = longer reaction time?
Which temperature are not working.
Can anybody help and explain the reasons of temperature and cooking time?
Thank you a lot.
Either way. That relation time/temp thing is only important for those in a constant hurry. The fact that a reaction takes a certain time doesn't mean you need to stopwatch tightly. Product doesn't walk away. On 35 overnight, 25 overnight, 40 in 2 hours, 40 in 8 hours . you'll get the same output (where, imho, longer = better).
↑View previous replies…
experimentsciAfaik methylamine is added in quadruple excess (foolproof). It depends on the conditions. High temps, rapid stirring, open vessel, ensures a lot of it evaporates (which is not what we want).
I roughly use x 1.5
It's actually a matter of just trying and find the optimal variables as you go . There are too much for a "one size fits all".
Last Saturday did 200g batch using 400ml ethyl acetate and 400ml methylamine. That failed heavily (twice).
as I'm typing, doing another 200g batch (image). 350ml methylamine, 500ml ethyl acetate. Never fails (for me, at least).
If I would use DCM i take 600ml DCM.
TheVacuumGuy400g bromoketone
1000ml DCM
800ml Methylamine
39 Celsius
6 hours (unintentionally, fell asleep)
In the morning added 1000ml water.
TheVacuumGuyAnd how much gram 4mmc u get?
$!$It finished drying to complete dryness just now. i got 265,5 gram. Could have been higher if i actually didn't forget to wash it 3 times.
Will also get losses when crystallization to account for, so finally it will end up bit lower.
$!$i just finished reacting another one, 200g, 800ml DCM, 400ml Methylamine. ~2.5h 40 celcius.
now in freezer to prepare for acidify. curious to see if it yields more and better.
TheVacuumGuyyesterday acidified, white yellowish-hue (Cream-like), started with 500ml (freebase-in-solvent) when took it from the freezer.
Acidifying, became thick, pouring aceton made volume much larger , still thick., so sended up 2000ml still quite thick creamy like substance which looks beautiful.
I decide not for adding more acetone as, a moderate thickness keeps vacuumdistill much more clean.
This morning took it from freezer. Still the same beautiful off-white color. Took it through vacuum distill, no acetone needed ecept for rinsing the beaker of leftovers.
I used the same dish as the (400g couple of reactions above), to dry.
can't see by the eye exactly, but it looks like nearly (minus a bit) as much. will report when dry.
- Joined
- Sep 20, 2023
- Messages
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- Reaction score
- 34
- Points
- 28
Thank you very much for your answer. I am just afraid, that, when I let everything react longer, that more side-products will increse and impury my product.
My last batch, I washed out the blue colour with acetone during filtering. I will send product to a labor to check, if it is good.
I also checked, that I used a little to much Methylamine. For 100g Bromketone I added 200ml Methylamine 40%a.q. solution.
I think 160ml should be enough (after calculation 1mol Bromketone vs. 2 moles Methylamine and a little buffer for Methylamine)
I roughly use x 1.5
It's actually a matter of just trying and find the optimal variables as you go . There are too much for a "one size fits all".
Last Saturday did 200g batch using 400ml ethyl acetate and 400ml methylamine. That failed heavily (twice).
as I'm typing, doing another 200g batch (image). 350ml methylamine, 500ml ethyl acetate. Never fails (for me, at least).
If I would use DCM i take 600ml DCM.
Attachments
- Joined
- Sep 20, 2023
- Messages
- 101
- Reaction score
- 34
- Points
- 28
Afaik methylamine is added in quadruple excess (foolproof). It depends on the conditions. High temps, rapid stirring, open vessel, ensures a lot of it evaporates (which is not what we want).
I roughly use x 1.5
It's actually a matter of just trying and find the optimal variables as you go . There are too much for a "one size fits all".
Last Saturday did 200g batch using 400ml ethyl acetate and 400ml methylamine. That failed heavily (twice).
as I'm typing, doing another 200g batch (image). 350ml methylamine, 500ml ethyl acetate. Never fails (for me, at least).
If I would use DCM i take 600ml DCM.
1000ml DCM
800ml Methylamine
39 Celsius
6 hours (unintentionally, fell asleep)
In the morning added 1000ml water.
![Cws7XTDVEa Cws7XTDVEa](https://bbmarket.biz/data/attachments/38/38027-ed864676c1370b2d8f081a503a4a8b68.jpg)
400g bromoketone
1000ml DCM
800ml Methylamine
39 Celsius
6 hours (unintentionally, fell asleep)
In the morning added 1000ml water.
View attachment 38021
- Joined
- Sep 20, 2023
- Messages
- 101
- Reaction score
- 34
- Points
- 28
And how much gram 4mmc u get?
Will also get losses when crystallization to account for, so finally it will end up bit lower.
Last edited:
- Joined
- Sep 20, 2023
- Messages
- 101
- Reaction score
- 34
- Points
- 28
And how much gram 4mmc u get?
now in freezer to prepare for acidify. curious to see if it yields more and better.
- Joined
- Sep 20, 2023
- Messages
- 101
- Reaction score
- 34
- Points
- 28
i just finished reacting another one, 200g, 800ml DCM, 400ml Methylamine. ~2.5h 40 celcius.
now in freezer to prepare for acidify. curious to see if it yields more and better.
Acidifying, became thick, pouring aceton made volume much larger , still thick., so sended up 2000ml still quite thick creamy like substance which looks beautiful.
I decide not for adding more acetone as, a moderate thickness keeps vacuumdistill much more clean.
This morning took it from freezer. Still the same beautiful off-white color. Took it through vacuum distill, no acetone needed ecept for rinsing the beaker of leftovers.
I used the same dish as the (400g couple of reactions above), to dry.
can't see by the eye exactly, but it looks like nearly (minus a bit) as much. will report when dry.
Last edited: