Wednesday, February 20, 2013

Bonus Process Wednesday: small-scale agitation parameters

If you're following Blog Syn #002 (Selective C-H Olefination of Pyridines, by J.Q. Yu et al.), it seems that that agitation is the key to the reaction. From Professor Yu's e-mail:
Put the reaction tube in the middle of hot plate to obtain a stable stirring (500 rpm is enough). Don't let the solid adhere to the tube wall. 
I wonder if, for heterogeneous reactions, there should be a standardization of the parameters for agitation, i.e. size/weight of stir bar, inner/outer diameter of reaction flask, type/size of stirplate, etc.

It'd probably save some people a little bit of grief. 

1 comment:

  1. It makes sense if the ultimate oxidant is air (although you have plenty of silver carbonate). It slowly gets used up over time and you only have a 50mL tube. If it was possible to put a needle connected to an air cylinder at the bottom of the reaction and bubble it, maybe the result would have been better, but you can't really do that at 140C with DMF.

    At least the reaction works. IBX on the other hand? Well...

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