Author Topic: Replacing Phenyl Lithium GB861350  (Read 2291 times)

0 Members and 1 Guest are viewing this topic.

Bwiti

  • Guest
Replacing Phenyl Lithium GB861350
« on: June 04, 2002, 12:04:00 PM »
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

  • Guest
Wurtz?
« Reply #1 on: June 04, 2002, 12:06:00 PM »
Wouldn't p-bromotoluene/potassium undergo wurtz coupluing to form the 4,4'-dimethylbiphenyl?

hypo

  • Guest
uh huh
« Reply #2 on: June 04, 2002, 12:11:00 PM »
you probably better run fast when adding potassium to bromotoluene  ;)

Bwiti

  • Guest
Oops! Chlorobenzene then. :-P
« Reply #3 on: June 04, 2002, 02:54:00 PM »
Oops! Chlorobenzene then. :P
  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

  • Guest
patent technique
« Reply #4 on: June 04, 2002, 03:15:00 PM »
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.