The 2006 ACS meeting in SF was interesting. In a much earlier post I lamented the recent trend of boring ORGN section meetings. That was definitely not the case this time around.  Of course, there was the usual assortment of faculty rockstars with their fawning groupies (OK, I’ve done that too). A lot of interesting insights into obscure stuff.  But I have to say that there was more buzz in the air in the ORGN talks.  My favorite profspiels included Toste, Doyle, Knochel, and Trost.

This time I noted a distinct lack of talks on room temperature ionic liquids (RTIL’s). After far too much breathless ballyhoo, the worker bees in this “area” seem to have hunkered down a bit.  Do I sound cynical? I have actually developed a manufacturing process for a commercial RTIL species. I can say that the economics of RTIL manufacture and certain kinds of applications of these expensive solvents can be awful.  At least awful in direct comparison to solvents like THF, toluene, ether, etc. If you’re using an RTIL, say, in a two-phase catalytic extraction process, then the comparison is faulty and the RTIL may be quite efficient to use.  However, if you need batch reactor volumes, i.e., 50 to 1000 gallons, then the batch process costs may require scientific notation.

Even pharma companies with deep pockets extending to the MOHO layer will worry about these economics.  In order to justify an $50-$250/kg solvent (!!), there has to be some whiz-bang process improvent to justify such costs.  In batch processing, RTIL’s are prone to the concentration of ionic species or water from the previous run. The practical consequence of this is that the RTIL may be a different material from one run to the next. It may or may not be an issue. But you’ll have to investigate and qualify it. You may have to polish the solvent (!!!) after each run to qualify the subsequent use of the RTIL. How green can that be?  

I cannot speak from the perspective of a pharma industry chemist. But I can speak as someone who makes specialty products for the pharma business. From bitter experience I can testify that the last thing you want to be is the supplier of the most expensive reagent in the customers process.  It is like a rock in their shoe. They’ll squirm and fitch around until they find a cheaper supplier or engineer a way around the offending reagent. Hell, I’d do the same thing in a heartbeat. Nothing wrong with that. But it is this sort of raw cost pressure that makes the commercial viability of RTIL’s difficult. 

The disposal of bulk RTIL’s may be expensive too.  Since as a group they are resistant to incineration, the natural question is- How do we safely and ethically dispose of bulk RTIL’s?  I’m sure that someone out there in the blogosphere has a comment on this.

<END RANT>