ORGLIST: Removing excess Triphosgene

Date view Thread view Subject view Author view Attachment view

From: Kamal (mailbox$##$invalid)
Date: Wed Aug 31 2005 - 09:42:12 EDT


Hi to all my orglist friends !

I'm still struggling with my developement of an aliphatic Isocyanate. =
(Sorry to Yuehui & Lakshmipathiji, again disturbing you !!)

As per the advice given to me by you, I performed procedure of ORGANIC =
SYNTHESIS by using Amine HCl, Triphosgene, Dichloromethane & aq. =
bicarbonate. The reaction goes so well but I'm feeling difficulties in =
removing the excess triphosgene after completion of reaction.

I used 0.35.......to......0.5 eq. of triphosgene in different =
experiments & all give almost similar results. In all of them, excess =
triphosgene remains in the organic layer & generates a lot of amount of =
acidic solids. It still remains in the distilled isocyanate also ! If I =
use lower ratio of triphosgene (0.33 eq. or less), then some Amine HCl =
remains unconverted & it makes other urea/hydantoin based impurities in =
significant amounts !

Is it possible to remove this excess triphosgene ?

Pls...................give some advice to me.




Thanking you,
Kamal
(mailbox$##$invalid)




_______________________________________________
ORGLIST - Organic Chemistry Mailing List
Website / Archive / FAQ: http://www.orglist.net
To post a message (TO EVERYBODY) send to everybody$##$orglist.net
To unsubscribe, send to everybody-request$##$orglist.net the message: unsubscribe your_orglist_password your_address
List coordinator: Joao Aires de Sousa (coordinator$##$orglist.net)




Date view Thread view Subject view Author view Attachment view

This archive was generated by hypermail 2.1.4 : Thu Feb 18 2010 - 16:58:09 EST