Testing Phase Transfer Catalysts in a Malonic Ester Synthesis.
Aim: To test 15 calalysts in the Malonic Ester Synthesis of tButyl MalonicEster.
Experimental: 16 runs (including control) using the Polyethylene Glycols as catalysts. 16 x 120ml Beatson glass medicinals with
polypropylene caps loaded into a multireactor (Fig1) .
The multireactor is placed in a lab oven at 55degC and rotated at 100rev/min via a flexible-drive speed-controlled motor. (Fig2).
The reaction took 24Hr after which each sample was tested with TLC using tBuMeEther/Heptane as solvent, and visualized with iodine. Fig3 is a
summary.
Results: The lower PEGs were best, even triEthyleneGlycol, and there seems no advantage in using capped PEGs. Fig4 is the TLC results showing
the tBuMethylEster standard (Merck), and the pure MalonicEster.
Comment: This method may prove useful in initial screening of PTCs for a given reaction. Curiously there seemed to be no build up of
pressure within the bottles even though the stoic shows the release of CO2. No product was seen for the control (No7) and for the standard
MalonicEster.
   
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