kamal - 14-9-2005 at 06:21
Hello friends !
I'm doing one reaction in which an aliphatic isocyanate is formed thro' reaction of Amine HCl with Triphosgene (0.35-4 eq.) in aq.
bicarbonate & dichloromethane media.
The reaction goes so well but only the problem here is I could not get rid of the excess triphosgene remained after the reaction. If I use lower ratio
of triphosgene, then reaction does not being complete & urea formation occurs.
Can anyone pls suggest me how can I remove this excess triphosgene ?
Awaiting yr comments !
Regards & Thanx in advance,
Kamal
kazaa81 - 15-9-2005 at 13:32
Hello kamal,
I think which knowing triphosgene properties may help....
http://en.wikipedia.org/wiki/Triphosgene
It is writed which it decomposes at 130°C....it this temp. won't damage your experiment.....
Hope this helps 
kamal - 15-9-2005 at 21:20
No dear !
I can not go upto this temperature during or after my reaction to remove the TPG. It decomposes my Isocyanate at this temp.
Do you have any suggetions for this by using act. charcoal or some other reagent ?
Rgds,
Kamal
Nicodem - 16-9-2005 at 06:22
Does triphosgene really decompose so slowly in an aqueous solution that you actually have to remove it?
Unless the isocyanate reacts faster you might use ammonia to remove triphosgene.