tag:blogger.com,1999:blog-8964719845369935777.post7389672358363258662..comments2024-03-27T21:23:40.339-04:00Comments on Chemjobber: Process Wednesday: how to choose a scale-up partner? Chemjobberhttp://www.blogger.com/profile/15932113680515602275noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-8964719845369935777.post-34501022251552563522013-04-04T08:48:52.491-04:002013-04-04T08:48:52.491-04:00I agree with the first comment – competence with p...I agree with the first comment – competence with process safety is crucial. <br />I found that the easiest way to learn the ropes is a continuous interaction with process engineers (and it helps to take some engineering courses in college). Getting calorimetry data on chemistry that you develop puts you in the right frame of mind. You have to think about heat transfer and mass transfer on scale (which is a huge field in itself, but I’ll just mention a couple of seemingly trivial issues that stumped people – would your slurry flow, or can it be pumped? Is it possible to filter it, or will the mother liquor evaporate, because the filtering cloth is silted?) You have to balance your equations (your protecting groups do not just “fall off”) and really track the fate of your chemical inputs. You’d be surprised at how many truly bright chemists get themselves painted into a corner when they realize that they generated a gaseous byproduct that makes the reaction mixture erupt on large scale, that their workup conditions result in a highly hazardous byproduct, or that an innocuous quench reagent left as a residue from previous step reacts in the next step. <br />Which bring to mind the next point: I agree with Chemjobber – you have to be very thorough with your analytical methods. In fact, I think process chemist is the last line of defense when it comes to having an adequate set of sound analytical methods for the process. <br />You have to learn about crystallizations (and get at least an inkling of how to develop one). <br />Bottom line, a process chemist needs to think like a/n (organic) chemist, an analytical chemist, a process engineer and a plant operator (you always have to see yourself next to a large reactor performing – with your own two hands - all the steps that you have performed on a small scale, which means you have to have familiarity with large scale equipment). <br />I’m sure I’ve missed some important points – I feel rather strongly about the subject and wanted to give my 2 cents - but it’s time to get to work. :-) Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8964719845369935777.post-7192857495138508902013-04-03T12:41:48.906-04:002013-04-03T12:41:48.906-04:00Colleagues were in Freiburg transferring our (some...Colleagues were in Freiburg transferring our (somewhat tricky) procedure to a German CRO that was scaling it for us under GMP. The guys there were Teutonic-thorough and asked a lot of questions about every damned detail - questions just like those that you mentioned. They made sure to get the same columns as we had for GPC analysis and the same NMR pulse sequence for their NMR like we use (our stuff was polymeric so one needs long acquisition time even for simple proton NMR)milkshakehttp://orgprepdaily.wordpress.comnoreply@blogger.comtag:blogger.com,1999:blog-8964719845369935777.post-6093265608864182442013-04-03T12:01:47.361-04:002013-04-03T12:01:47.361-04:00While I agree a strong sense of quality and analyt...While I agree a strong sense of quality and analytical details is important for process chemist there are many other attributes that can differentiate good process chemists. I always put Safety mindset at the top as although we chemists can sometime be caviler in the lab such unawareness at large scale can be true recipe for disaster (this may be nebulous to determine but also believe can be learned if willing). And even though I never liked PChem it comes in very handy in many aspects of scale-up, again some tied to safety such as thermodynamics but the ability to understand and see alternate reaction mechanisms is vital. The ability to be flexible and adaptable are useful traits, especially under pressure, as is being able to work with diverse teams across many levels and disciplines since for a period of time in development they can play a central role in advancement of projects. A few more I could suggest as well but interested to see others input. CMCguyAnonymousnoreply@blogger.com