09-27-01 03:40
No 217667
after a long summer break uemura browsed thru the hive and found a procedure for preparation of ketones on Rhod's page. See http://www.orgsyn.org/orgsyn/prep.asp?pr
This variant uses p2np solved in toluene which is converted to the ketone with HCl and iron. The authors prepare the o-methoxyP2P which is removed from the rxn mix by steam destillation and say at the end, This procedure is quite general for other aromatic aldehydes.
NOW, Question: does any bee know of ketones (x-P2P) which CANNOT bee steam destilled?
Will this procedure work for P2P, p-methoxy-P2P, TMA-P2P?
Thanx for attention.
Cape Diem
(Chief Bee)
09-27-01 08:38
No 217738
It will work for P2P and 4-MeOP2P as far as I know. I don't think it would work with TM-P2P.
(Old P2P Cook)
09-27-01 19:16
No 217997
It works very well for P2P. As Osmium has said, and as a vapour pressure table I recently saw indicates, it will not work very well for MDP2P.
MDP2P has a vapour pressure of only about 1 mmHg at 100°C. This means that the distillate will be about 0.13 mol% MDP2P
or about 1.3 weight % MDP2P.
I presume that TMAP2P would have an even lower vapour pressure than MDP2P and thus give an even lower mol% distillate.