The Vespiary

The Hive => Chemistry Discourse => Topic started by: Elementary on July 20, 2002, 11:16:00 PM

Title: Vogel Phenylacetic preparation ?
Post by: Elementary on July 20, 2002, 11:16:00 PM

This looks wrong :

(https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000335185-file_hnrd.jpg)

I thought that dry ice was also needed.

Also, can carbon dioxide gas be bubbled into the grignard rxn instead of using dry ice ?

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I've got nothing to do today but smile !

Title: yields
Post by: lugh on July 20, 2002, 11:52:00 PM

Since that's a cognate preparation, one must look at the above synthesis to find little details like using carbon dioxide  ;D  Yields are best by pouring benzylmagnesium chloride directly onto powdered dry ice, bubbling CO2 gas is very low yield  :(

Title: I did this reaction once on a highly substituted ...
Post by: Osmium on July 22, 2002, 11:25:00 AM

I did this reaction once on a highly substituted benzyl chloride by simply throwing chunks of frozen CO2 into the flask containing the grignard and the yields were pretty good. Don't bother with powdering etc, you will introduce too much water. Just crush the CO2 enough so it will go through the joint.

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