# Bromination of 4-methylpropiophenone with NBS/PTSA and solvent-free conditions (large scale)



## William Dampier (Sep 12, 2021)

*Reaction scheme:*





*Synthesis:*
1. 1000 g 4-methylpropiophenone and 117 g of anhydrous p-toluenesulfonic acid were added to the flask.
2. Start stirring an over-head stirrer at room temperature.
3. 1200 g NBS added with small portions with constant stirring.
4. Control the temperature of the mixture to 75*C.
5. The entire reaction takes about three hours.
6. At the end of the reaction, discoloration and thickening of the solution, we pour gradually cold water and stirring.
7. Filter the resulting crystals from water, can be used crude bromoketon, theoretical yield: 1400 g.


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## Venom2021

1000g 4methylopropiophenone how much will be ml?


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## Venom2021

this synthesis can be done 3 times faster in the microwave.


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## G.Patton

Venom2021 said:


> 1000g 4methylopropiophenone how much will be ml?



Venom20211000 g/0.991 g/ml= 1009.08 mL


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## hustla

So first I should make my ptsa anhydrous if I have monohydrate, right? Melting and boiling it in 115C for 2h will do?

Or I should strictrly follow preparation and keep it molten in 115C for 14+h in inert gas like nitrogen (which I want to avoid)?


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