Bwiti (PVC-Analog Taste-Tester)
06-04-02 12:04
No 317580
      Replacing Phenyl Lithium GB861350  Bookmark   

EXAMPLE 7. from GB861350:

A mixture of 196 g. of cyclohexanone, 146 g. of n-butylamine, and 600 ml. of benzene was refluxed under a water trap until 36 ml. of water had been removed, The solution of cyclohexylidene-n-butylamine was added to a previously prepared, stirred solution of three moles of phenyl lithium in 3 liters of ether.
The resulting solution was stirred and refluxed for two hours, then decomposed by the cautious addition of 500 ml. water, blah, blah, blah.


  In the above example, I'd like to replace the phenyl-lithium with p-bromotoluene/potassium. <- How much of each should I use to convert the cyclohexylidene-n-butylamine? Would I need a Lewis acid like Mg-chloride or bromide? 

Love my country, fear my government.
 
 
 
 
    Rhodium
(Chief Bee)
06-04-02 12:06
No 317581
      Wurtz?  Bookmark   

Wouldn't p-bromotoluene/potassium undergo wurtz coupluing to form the 4,4'-dimethylbiphenyl?
 
 
 
 
    hypo
(Hive Addict)
06-04-02 12:11
No 317584
      uh huh  Bookmark   

you probably better run fast when adding potassium to bromotoluene wink
 
 
 
 
    Bwiti
(PVC-Analog Taste-Tester)
06-04-02 14:54
No 317623
      Oops! Chlorobenzene then. :-P  Bookmark   

  Oops! Chlorobenzene then.tongue
  Also, if cyclohexylidene-n-butylamine was added to phenyl-magnesium-bromide(PMB), would the yield of product be just as good as with using phenyl-lithium? Does the cyclohexylidene-n-butylamine need to be made into a salt by addition to p-toluenesulfonic acid before PMB is added. All of the patents that say Mg can be used instead of lithium don't say if the reaction needs to be altered because of this change in metals used. A few patents say that phenyl-potassium or phenyl-sodium can be used, but the bastards don't show their use in the example sections.

Love my country, fear my government.
 
 
 
 
    Rhodium
(Chief Bee)
06-04-02 15:15
No 317637
      patent technique  Bookmark   

They only write that to cover as much ground as possible with their patent, it doesn't mean you can use Na/K in practice with good results.