Mcat synthesis issues #2

MasoN

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Hello again to the experts, friends and all chemists
I have posted a threat about my problem with the yield which it was not more than my finger tip size, and some nice guys gave me some advice and tips, and I considered them.
So this young chemist repeated the synthesis with his broken hand :) and got to the same issue, but enjoyed sharing more details for you comrades hope to solve the riddle:)
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My scale was

-25g propiophenone

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-50 ml of a diluted Hbr (that i had made it via 20g KBr in about 70-80ml Distilled water, adding 15ml H2SO4 dropwise, freezed the solution to divide the side-products, then heated to evaporate then got the distilled solution contain Hbr.)
-15ml H2O2 35%
-75ml DCM
-12g Na2CO3 in 250ml DW(distilled water)
-35ml Methylamine 40% aqueous solution
-25ml HCl 14% solution (I got that from diluting 10ml HCl 38% in 15ml DW)
-another 10ml DCM and 20ml Water contains 0.5ml HCl

Now the process:
1. Adding propio to the flask, adding Hbr solution, then adding H2O2 dropwise in about 40min while the solution was being stirred in room temperature
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2,3. Adding DCM, and washing it to neutralized(for washing i transfer the reaction mixture into the decanter, after that i pour it back into the flask.)
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4. Adding Na2CO3 solution divided in 2 portions(2x125ml), then washing it to neutralized.
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5. I add all the methylamine at once, put the reflux condenser, and stir it for 1.5h in room temperature.
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5.5 I washed it 3-4 times with about 75ml DW, it was still alkaline then.

6. I added Hcl solution (i did it too fast so a lot of fog occured in the flask, next time I will handle that), stirred for 1 hour in room temperature.

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7. I take out the dcm layer, wash it with that acidified DW i had said before. Then i mixed first and this aqueous layer and washed them with 10ml DCM.
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8I poured the solution into a beaker and heated it until crystallization.
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9. Finally this is what i’ve got😑
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___________________
I need to figure my mistake
What did i forget?
Where was i wrong?
Please notify me!
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Great love to all…
 

HeavenChem

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Your bromination process is not clear for me
On what temperature you maintained your reaction ?
How heat was maintained, only on hot plate or it was heated first and supported heat only with adding H2O2 ?
 
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