potisgood (Stranger)
04-10-01 05:00
No 183176
      fucked up synth for mdp2p  Bookmark   

I don't know if anyone's come up with this before or if it is known not to work, but I came up with a synth using general knowledge of organic chemistry to make mdp2p from acetone and catechol. Take a look at it and see if anything won't work:

1) Methylate catechol to give methylenedioxyphenyl.  Easy as fuck to do.

2) Brominate aromatic ring using Br2 (lewis acid catalyst shouldn't be necessary since the ether group is extremely activating for electrophilic substitution).

3) Convert to a grignard reagent (there's an example of this in my organic textbook.  would only require magnesium strips).

4) Brominate acetone at the alpha carbon with Br2.  Should be easy as fuck.

5) Convert carbonyl group on acetone to an acetal with ethylene glycol and acid. This is one step that might not work since the electronegativity of the alpha bromine might make the intermediate carbocation unstable.  Probably will work though.

6) React acetal/bromide with grignard reagent. If this synth doesn't work, this is the step that will fuck it up. The basic grignard should attack the alpha carbon, displacing the bromide in an sn2 fashion. The main difficulty is that the ajdacent carbon is fully substituted and may give steric hindrance. Then again, the grignard is such a strong base that the reaction will probably occur anyway.

7) Convert the acetal back to a ketone to get the fucking product!!

If this shit works, is could mean a fairly quick and easy synth of ketone from fucking catechol and acetone. The best part is that the two *pieces* are made separately in quick, easy, and most likely already documented processes, producing maximum efficiency due to the cheap ass starting materials. This would prevent the loss from building up as a single path synth would (as opposed to this two path syth). Also, you can carry out both paths simultaneously (make acetal/bromide and grignard at the same time in two separate ba...
04-20-01 00:52
No 185345
      EXTREME CAUTION  Bookmark   

You'd best be VERY careful of you want to go through with this type of synthesis. Bromoacetone is a severe lachrymator (read: tear gas). This is why in college organic lab you are told to never wash glassware containing bromine with acetone. Please don't fuck with this unless you've got a good fume hood.

Other possible problem with this synthesis is as you've described. The Sn2 displacement of brmoide from the ketal may be problematic as the bromide resides at what basically amounts to a neopentyl position. Not the best for Sn2. Perhaps if you have access to butyllithium, make the organolithium instead of the Grignard--much more basic, and more importantly, much more nucleophilic. Use 2 eq. of BuLi to the aryl bromide for best results.

Ketal formation is trivial if you use the right acid. Best bet is p-toluene sulfonic acid if you can get it.

07-13-01 04:05
No 190252
      Re: EXTREME CAUTION  Bookmark   

You'd probably have better luck buying it from some Chink overseas.

Assrash Ouch!
(Hive Elder)
07-13-01 19:14
No 190398
      EXTREME CAUTION  Bookmark   

Watch your fucking mouth, joke or not, racial slurs are NOT permitted in any way, shape or form...