posted on 2013-01-07, 00:00authored byDale G. Drueckhammer, Steven Qizhi Gao, Xiaofei Liang, Junzhuo Liao
Solvents used in chromatographic purification of intermediates
and products are a major source of waste and expense in synthetic
research and synthetic processes. The ethyl acetate–hexane
mixtures most commonly used for flash chromatography on silica gel
are not readily separable by distillation due to their similar boiling
points and azeotrope formation. Potential solvents for chromatography
that are more amenable to separation and recovery by distillation
were thus explored. Acetone–heptane mixtures were found to
be convenient and sufficiently separable for routine use and recovery
for organic separations. The greater eluotropic strength and especially
the transparent short-wavelength UV window of acetone provide additional
advantages over the commonly used ethyl acetate. The recycling of
solvents from chromatography can greatly reduce the volume of waste
generated by synthetic laboratories while also reducing operating
costs.