So lets try to figure stuff out so we wont waste precursors.
we have 2 ways
1. from 4MP we brominate -> methylation
or we skip bromination and get 2br4mp and just do one reaction.
i saw various posters run into trouble so we will try to solve the problems one by one.
Synthesis:
2-bromo-4-methylpropiophenone (BK4) added to the reactor or have calculated amount of crude BK4 after halogenation reactions.
2. n-methyl-2-pyrrolidone poured, start stirring and heating to 40 *C.
3. Upon reaching 40 *C within the mixture, pour 8 liters methyl amine 40% aq.soln and continue stirring 20 minutes.
#___should the temprature stay 40*C or should it be closer to 60 like one of the posts i saw ?
#___also what time would the reaction need to run for DMSO, DMF, Sulfolane?
4. Next, we pour 20 liters of clean cold water, stirring a few minutes.
5. Pour 15-20 liters benzene or other suitable extractor, stirring a few minutes.
#___What would be the ideal suitable extractor ? i saw many people dont want to use benzene as its carcinogenic
would DCM or toluene do the same job?
Can the extractor be evaporated only leaving crude 4mmc and just dissolve it in acetone for the powder to participate?
if not is there any benefit to benzene AS AN EXTRACTOR compared to DCM or Toluene , would any of the steps be modefied if those are used instead ?
also can the water be just tap water or need Distilled water?
6. Stop stirring, waiting for the separation of the mixture into two layers.
7. The bottom aqueous layer was drained through the bottom valve of the reactor.
the bottom layer will contain H2O and NMP right? can the NMP be distilled and used again ?
8. 20 liters of ice acetone was poured and add hydrochloric acid with stirring to pH - 5
9. Overload the mixture in the freezer.
10. Filter on the nutshe-filter, dry.
Trouble shoot !
1.i saw people try the steps and come with a blue product , do you know the reason for it ? , maybe they used something different then NMP thus the reaction didnt complete ? , or added hcl to fast? , maybe add diluted hcl 1:1 acetone would be better?
2.Low yield , as i understand a good enough yield would be 60% , but i saw people get low as 15% , maybe they replaced NMP and the reaction needed more time and it didnt complete? , of that happen , can you try to evaporate everything that didnt became powder and try and do the reaction again ? (if the bk4 is still there unreacted?)
ok so we can also start with 4mp but then we need to do bromination
getting elemental bromine can be pain in the ass , i can distill it with Kbr sulfuric acid and h2o2 , but i guess no need to destill it , can just generate the bromine in situ and just use the BK4 for later reactions.
bbzzzsvqcrqtki6umym6itiixfhni37ybtt7mkbjyxn2pgllzxf2qgyd.onion/threads/bromination-of-4-methylpropiophenone-with-hbr-h2o2-large-scale.215/
so what am i getting here ? only a cheaper reagent and an additional reaction ?
how much is the bk4 yield ? , from the benzene sythesis the operator gets 100g 4mmc from 100g 4mp which is great id say , but lets say we get 1000g bk4 from 1L 4MP we will still end up with about 600g 4mmc , but according to original sythesis with bromine we get ~1:1
1L 4MP = 1kg 4mmc , is it because bromination with elemental bromine is more efficient? maybe more 400g of 4mmc worth the pain in the ass of making bromine?
we have 2 ways
1. from 4MP we brominate -> methylation
or we skip bromination and get 2br4mp and just do one reaction.
i saw various posters run into trouble so we will try to solve the problems one by one.
Synthesis:
2-bromo-4-methylpropiophenone (BK4) added to the reactor or have calculated amount of crude BK4 after halogenation reactions.
2. n-methyl-2-pyrrolidone poured, start stirring and heating to 40 *C.
3. Upon reaching 40 *C within the mixture, pour 8 liters methyl amine 40% aq.soln and continue stirring 20 minutes.
#___should the temprature stay 40*C or should it be closer to 60 like one of the posts i saw ?
#___also what time would the reaction need to run for DMSO, DMF, Sulfolane?
4. Next, we pour 20 liters of clean cold water, stirring a few minutes.
5. Pour 15-20 liters benzene or other suitable extractor, stirring a few minutes.
#___What would be the ideal suitable extractor ? i saw many people dont want to use benzene as its carcinogenic
would DCM or toluene do the same job?
Can the extractor be evaporated only leaving crude 4mmc and just dissolve it in acetone for the powder to participate?
if not is there any benefit to benzene AS AN EXTRACTOR compared to DCM or Toluene , would any of the steps be modefied if those are used instead ?
also can the water be just tap water or need Distilled water?
6. Stop stirring, waiting for the separation of the mixture into two layers.
7. The bottom aqueous layer was drained through the bottom valve of the reactor.
the bottom layer will contain H2O and NMP right? can the NMP be distilled and used again ?
8. 20 liters of ice acetone was poured and add hydrochloric acid with stirring to pH - 5
9. Overload the mixture in the freezer.
10. Filter on the nutshe-filter, dry.
Trouble shoot !
1.i saw people try the steps and come with a blue product , do you know the reason for it ? , maybe they used something different then NMP thus the reaction didnt complete ? , or added hcl to fast? , maybe add diluted hcl 1:1 acetone would be better?
2.Low yield , as i understand a good enough yield would be 60% , but i saw people get low as 15% , maybe they replaced NMP and the reaction needed more time and it didnt complete? , of that happen , can you try to evaporate everything that didnt became powder and try and do the reaction again ? (if the bk4 is still there unreacted?)
ok so we can also start with 4mp but then we need to do bromination
getting elemental bromine can be pain in the ass , i can distill it with Kbr sulfuric acid and h2o2 , but i guess no need to destill it , can just generate the bromine in situ and just use the BK4 for later reactions.
bbzzzsvqcrqtki6umym6itiixfhni37ybtt7mkbjyxn2pgllzxf2qgyd.onion/threads/bromination-of-4-methylpropiophenone-with-hbr-h2o2-large-scale.215/
so what am i getting here ? only a cheaper reagent and an additional reaction ?
how much is the bk4 yield ? , from the benzene sythesis the operator gets 100g 4mmc from 100g 4mp which is great id say , but lets say we get 1000g bk4 from 1L 4MP we will still end up with about 600g 4mmc , but according to original sythesis with bromine we get ~1:1
1L 4MP = 1kg 4mmc , is it because bromination with elemental bromine is more efficient? maybe more 400g of 4mmc worth the pain in the ass of making bromine?
