Sciencemadness Discussion Board

Synthesis of o-chlorophenyl Cyclopentanone

zhouxiaogui - 22-1-2022 at 22:59

I use chlorocyclopentane and toluene as Grignard reagent and toluene as solvent. Grignard reagent is OK. O-chlorobenzonitrile was added dropwise at 80 ℃, and then kept at 80 ℃ for 6 hours. Then quench the reaction with water after cooling, and drop hydrochloric acid at no more than 25 ℃. After dropping, keep at 70 ℃ for 5 hours Acid water extraction, combined with the organic layer, first distill out the toluene solvent, and then distill it under reduced pressure. There are also yellow liquids distilled out, but it is not o-chlorophenyl cyclopentanone. Later, it was found that o-chlorobenzonitrile did not react well.I wonder if the reaction temperature of o-chlorobenzonitrile at 80 ℃ is wrong.

Antigua - 23-1-2022 at 03:10

A copper(I) catalyst is required :)

zhouxiaogui - 23-1-2022 at 03:40

Quote: Originally posted by Antigua  
A copper(I) catalyst is required :)


If copper catalyst is not used, can the reaction be carried out by raising the reaction temperature?

Antigua - 23-1-2022 at 04:16

Yes, but why would you do that? Copper iodide or bromide is very easy and cheap to make...
https://pubs.acs.org/doi/abs/10.1021/jo00226a033

zhouxiaogui - 23-1-2022 at 04:18

Quote: Originally posted by Antigua  
Yes, but why would you do that? Copper iodide or bromide is very easy and cheap to make...
https://pubs.acs.org/doi/abs/10.1021/jo00226a033


I don't know other methods. The process given to me by others is made of chlorinated cyclopentane. And in China, all people use chlorinated cyclopentane.

Antigua - 23-1-2022 at 04:36

Leave if you're a wannabe cook. Stay if you want to be a chemist.
Following "processes" or "recipes" from others will surely lead you to success...
This Grignard reaction still uses cyclopentyl halide, I just suggested to add a copper catalyst to make it quicker. I'm sure that they came up with that in China too. You guys are after all the largest ketamine consumers on earth :P

zhouxiaogui - 23-1-2022 at 04:39

Quote: Originally posted by Antigua  
Leave if you're a wannabe cook. Stay if you want to be a chemist.
Following "processes" or "recipes" from others will surely lead you to success...
This Grignard reaction still uses cyclopentyl halide, I just suggested to add a copper catalyst to make it quicker. I'm sure that they came up with that in China too. You guys are after all the largest ketamine consumers on earth :P

Do you add copper bromide after dropping o-chlorobenzonitrile? What's the ratio? Whether copper bromide needs to be added in whole or in batches. Just read the literature you gave, which says that the highest yield is the reaction for more than 3 hours. Thank you first.The process they gave me was the Chinese process. They must have given me an incomplete process without the step of adding copper bromide. Thank you again

karlos³ - 24-1-2022 at 09:27

The Cu(I) halide is only used in minute quantities, and it can result instead of merely around fourty percent in twice as much, substrate-dependant of course.

Use the attached method.

Attachment: Procedure for Grignard addition to nitriles for ketone synthesis.pdf (5.9MB)
This file has been downloaded 97 times


zhouxiaogui - 24-1-2022 at 15:53

Quote: Originally posted by karlos³  
The Cu(I) halide is only used in minute quantities, and it can result instead of merely around fourty percent in twice as much, substrate-dependant of course.

Use the attached method.


Hello, can I add ketone bromide to the Grignard reagent, and then add the solution of o-chlorobenzonitrile dropwise to the Grignard reagent?

zhouxiaogui - 24-1-2022 at 21:38

Quote: Originally posted by Antigua  
Leave if you're a wannabe cook. Stay if you want to be a chemist.
Following "processes" or "recipes" from others will surely lead you to success...
This Grignard reaction still uses cyclopentyl halide, I just suggested to add a copper catalyst to make it quicker. I'm sure that they came up with that in China too. You guys are after all the largest ketamine consumers on earth :P


I'm not a cook, I'm just a craft sent by a friend. I experimented in the lab, but the result didn't come out. Just to answer some questions, o-chlorobenzonitrile and Grignard reagents should haveEasy to react, I just don't understand why they don't react. I have done a Magnesium Bromide Grignard reaction with a nitrile and it went well.