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Large scale bromination of 4-MPF with HBr/H2O2

Joni

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This reaction proceeds without the release of unpleasant gases to the outside. This technique is the best choice if it is not possible to work in a fume hood. And therefore - and the most ideal for reproduction on a large scale in the most ordinary home kitchen, in the most ordinary Ukrainian Khrushchev!!!) And at the same time, it is in no way inferior, but rather even superior in efficiency to bromination directly with liquid Br.

Chemical reaction scheme:
qmu05kgcdh-png.png
Реагенты:

  • 4-метилпропиофенион 1000 г,
  • Бромистоводородная кислота 48% водный раствор 1300 г,
  • Перекись водорода 35% 750 г,
  • Пищевая сода,
  • Вода.
Preamble:
The bromination reaction is easily scaled up under these conditions. The rule of thumb is to add the peroxide slowly to avoid splashing the reaction mixture. In the role of a mixing device, it is better to use an upper mixer, a magnetic mixer cannot cope with volumes from 2x l, it stops with sediment. Mixer blades must be coated with Teflon to avoid reaction with HBr acid.

Synthesis:
1.
1000 g of 4-methylpropiophenone is added to the flask.
2. 1300 g of 48% HBr acid is poured into a flask and stirred for 5 minutes.
3. 750 g of 35% hydrogen peroxide are added to the addition funnel.
4. We begin to add hydrogen peroxide dropwise to the stirred reaction mixture.
5. In the process of adding peroxide to the mixture, bromine is released, and when stirred, it dissolves, reacting.
6. Peroxide should drip at such a speed as
7. We control the reaction temperature, do not let the mixture boil.
8. In the second half of the reaction, discoloration takes longer, so add peroxide, focusing on the rise in temperature.
9. When all the peroxide has been added, leave the reaction for 4-12 hours with stirring, at room temperature.
10. After the specified time, we see that the finished bromketone-4 precipitated. We prepare a saturated solution of baking soda to neutralize the remaining acid.
11. After adding the soda solution, drain the water from the sediment through a sieve, rinse again with clean water.
12. Next, bromoketone is used for further reactions. The theoretical yield is 1500g.
 
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Qogete

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Есть тут кто кто это сварит?))
 
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