The Vespiary

The Hive => Methods Discourse => Topic started by: uemura on September 27, 2001, 03:40:00 AM

Title: P2P Steam Destillation
Post by: uemura on September 27, 2001, 03:40:00 AM

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?prep=cv4p0573 (http://www.orgsyn.org/orgsyn/prep.asp?prep=cv4p0573)

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.

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Cape Diem

Title: Re: P2P Steam Destillation
Post by: Rhodium on September 27, 2001, 08:38:00 AM

It will work for P2P and 4-MeOP2P as far as I know. I don't think it would work with TM-P2P.

Title: Re: P2P Steam Destillation
Post by: terbium on September 27, 2001, 07:16:00 PM

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.