potisgood (Newbee)
01-13-02 10:38
No 255978
      Mystery Liquid Produced by EtONO Wacker  Bookmark   

OK, it doesn't look like anyone has seen my post in the original thread, so I'll start a new one.  I just ran the KrZ ethyl nitrite wacker for the second time on a 23g safrole scale, but used the proper amount of EtONO this time (which sunlight told me about in the thread on the reaction).  The reaction seemed to run fine, running b/t 30-35C and steadily evolving NO gas.  Workup also went good, but when I distilled it, it really did some fucked up shit.  The first fraction came over between 111-116C and I have no fucking clue what it is.  It was a clear, refractive liquid that smelled somewhat like EtONO dissolved in EtOH.  I collected about 12 g of this stuff.  No safrole came over, and about 7-8 g of ketone came over.  This was from a 23 g safrole reaction.  Under the same vacuum, safrole comes over at around 130C, so the pressure is around 30 mm.  The ketone came over between 154C-164C and was neon yellow/green in color.  I would estimate that this mystery fraction has a bp of 210-220C at atmospheric pressure.  Does anyone have any idea what this fraction might be?  I have two theories:

1) It is some sort of azeotrope formed b/t the ketone and another mystery compound.  This other compound may be the ethyl acetal of the ketone that did not completely hydrolyze, even though I performed the hydrolysis exactly as the procedure described.

2) The mystery liquid is a degradation product of the ketone or the safrole.  Since it has a lower bp, it is not a polymer.  In order for it to have a lower bp than safrole, it would have to have a lesser molecular mass, since safrole contains no polar bonding other than the MD ring, which if hydrolyzed would only increase the bp.

I would put my money on the first theory.  I would really appreciate any help that I could get, as I believe that this reaction is the best and most overlooked method to get ketone.  I have another post detailing the first run I did with this reaction in the thread that the oringinal reaction was posted in (robots are the future).

Also, I could have sworn that I got a good deal of safrole to come over with my first attempt at the reaction.  I redistilled the prerun/postrun for that distillation and did not get back any significant amount of safrole.  I only got the mystery liquid and ketone back.  I had let it sit in my freezer for about a week, diluted with acetone.

One more thing.  The EtOH I am using to run the reaction in is Parks brand denatured alcohol, and the acetone I used to dilute the above mentioned mixture was also Parks brand.