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<DIV><FONT face=Arial size=2>Hi to all my orglist friends ! </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I'm still struggling with my developement of an
aliphatic Isocyanate. (Sorry to Yuehui & Lakshmipathiji, again disturbing
you !!) </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>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.
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>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 !</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Is it possible to remove this excess triphosgene
?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Pls...................give some advice to
me.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thanking you,</FONT></DIV>
<DIV><FONT face=Arial size=2>Kamal Morendha</FONT></DIV>
<DIV><FONT face=Arial size=2>(<A
href="mailto:mailbox@prolificint.com">mailbox@prolificint.com</A>)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
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