Flash chromatography is the most commonly used purification tool for organic and medicinal chemists whose reaction scales typically range from milligrams to grams. The column size to be used for the purification of these reaction mixtures is selected either by using the 1% rule which states that for many reaction mixtures, a crude reaction mixture load equaling 1% of the column’s media weight often will provide the needed purity, assuming the right elution method is selected. While this strategy can work, often chemists either overload or underload the selected column resulting in low product purity which requires re-purification. In both situations, the chemists wastes time, solvent, and the cost of the column.
How Scalable is Flash Chromatography?
January 11, 2022 at 2:08 PM / by Bob Bickler posted in Scale-Up, reaction, scale
Can Reaction Temperature Impact Synthetic Product Yield and Purity?
November 17, 2021 at 7:01 PM / by Bob Bickler posted in reaction, flash chromatography
Though this is a purification blog I do, from time to time, like to address synthetic chemistry experimentation findings in the desire to assist you with your reactions, as this is the front-end of your synthesis workflow. So, in this post, I report on some findings of the effect of reaction temperature on the synthesis of an amide, 2-amino-N-benzylbenzamide, a potential antibacterial compound[1].
Does reagent and reaction solvent order impact product yield and purity?
October 19, 2021 at 6:00 PM / by Bob Bickler posted in Solvents, Synthesis, reaction, reagent
This is a question I asked myself while I have been studying synthesis variables to see what, if any, impact each variable has on reaction product yield and purity. For this post, I evaluated the order in which I added reactants and solvent.
Can maximizing product yield and purity from messy reaction mixture be green?
October 5, 2021 at 8:42 PM / by Bob Bickler posted in Green, purification, reaction, orthogonal
Chemical reactions gone wrong, I’m sure we all have experienced this issue, I know I have. You add your reagents in the proper amounts with a suitable solvent and perform your reaction only to find your by-product yield was greater than your product; by a lot. So, what do you do to isolate what little product you created with maximum yield and purity without breaking the proverbial bank on a big flash column and the solvent required for the purification?
In-line Scavenging Simplifies Flash Column Chromatography Reaction Mixture Purification
November 20, 2020 at 2:55 PM / by Bob Bickler posted in Scavenger, reaction
I am always grateful for the feedback I get from my blog readers. Today's blog is in response for multiple requests for tips on purifying complex mixtures and suggestions for alternative sample loading techniques.
In this post, I will attempt to address both, to some degree anyway, with a single example using a scavenger resin.