Author Topic: Questions re: alkyl halide and pipe bomb...  (Read 675 times)

0 Members and 1 Guest are viewing this topic.

spectralmagic

  • Guest
Questions re: alkyl halide and pipe bomb...
« on: December 21, 2003, 06:36:00 PM »
While SWISM is on hiatus, he's asked me to do research...

alkyl halide:

In theory, would it be possible to form a bromoallylbenzene from a propenylbenzene using HBr solution which had been formed by mixing equimolar amounts of KBr and either HCl or H2SO4 in aqueous solution?  Would the KCl or K2SO4 interfere with the bromination?

Does the reaction with HCl to form chloroallylbenzene work worth beans?  Seems no, from what I've read...

aminating via pipe bomb:

I've read conflicting things about this, won't work, will work, yields from nothing to 50%...  assuming yield is 20% or higher SWISM is interested (the unreacted alkyl halide can be re-used, yes?)...  now, again in theory, assuming under normal conditions this method works, what would happen if instead of just MeAm in MeOH one were to use a solution of MeOH which contained both MeAm and NaCl (from freeing MeAm from HCl by adding NaOH)?  Would the NaCl interfere?  (presumably a molar excess of MeAm.HCl would be used, to prevent excess NaOH from decomposing the alkyl halide)


Rhodium

  • Guest
no, no, no...
« Reply #1 on: December 21, 2003, 09:13:00 PM »
(the unreacted alkyl halide can be re-used, yes?)...

There will be little unreacted halide left, most will have eliminated to propenylbenzene or alkylated already formed meth (which is at least as reactive as methylamine).

what would happen if instead of just MeAm in MeOH one were to use a solution of MeOH which contained both MeAm and NaCl (from freeing MeAm from HCl by adding NaOH)?  Would the NaCl interfere?  (presumably a molar excess of MeAm.HCl would be used, to prevent excess NaOH from decomposing the alkyl halide)

Water is formed: MeNH2.HCl + NaOH -> MeNH2 + NaCl + H2O

The halide won't dissolve in aqueous methanol, and the reaction works even more badly...


spectralmagic

  • Guest
Not as elegant as it looked.
« Reply #2 on: December 22, 2003, 05:35:00 AM »
There will be little unreacted halide left, most will have eliminated to propenylbenzene or alkylated already formed meth (which is at least as reactive as methylamine).

Oh.  That changes the attractiveness of this route...  hadn't realized *any* amine could/would react with the halide.

Water is formed: MeNH2.HCl + NaOH -> MeNH2 + NaCl + H2O

The halide won't dissolve in aqueous methanol, and the reaction works even more badly...


I knew H2O was formed, but thought the amount in question wouldn't make much difference, as I've read aqueous methylamine can be used in the pipe bomb (along with methanol), and figured that my method would involve much less water so should react better...  gassing MeOH with MeAm seems to be worth the extra work then...

Hmmm...  moving this idea to the back burner...  if SWISM ever investigates further he'll report back.