New advances in microwave technology

The advent of microwave-assisted synthesis has allowed chemists to rapidly optimize reaction conditions for combinatorial library development17-19. But how can one efficiently produce libraries of compounds employing chemistry developed and optimized 

Similar plate-based systems have been reported in the literature21. The final goal of these efforts was to be able to synthesize several hundred compounds per day using microwave optimized reaction conditions. 

Our initial attempts at using a plate-based systems for microwave synthesis relied upon commercially available systems. A simple plate turntable was available for the CEM Mars 5 system (CEM Corporation, Matthews, North Carolina, U.S.). Heating DMF to 130°C in the plates illustrated that the thermal stability of the plastic was an issue. The wells when heated above 90°C with solvent tended to melt and deform resulting in loss of solvent. In our investigation into higher temperature plates, we 

Our next effort was to more accurately mimic the conditions that we were using for library optimization in the single-mode microwave, namely pressurized reaction vessels. It has been shown that the key to higher yields in microwave-assisted synthesis is not solely the direct heating but also the pressure effect—the ability to run reactions at higher 

Krutzik, P.O., Hart, M.E. and Chamberlin, A.R., Increasing rates of reaction microwave-assisted organic synthesis for combinatorial chemistry, /. Combi. Chem., 2002, 4(2), 95-105. 

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