Hello everyone.hope you all will be fine. iam synthesising an organic compound but iam facing a problem .when i synthesised it and run from silica plate at 5:1 DCM and Methanol its show movement and give me good result but when i run this compound in the column chromatography my stationary phase is silica and mobile phase is DCM and MEthanol i start from 7:1 and then going down even 1:1 but did not work from it.PLEASE GIVE ME ANY SUGGESTION .because my compound is very complex my second reactant is 1,4 dimethylpyridinium iodide .should i tried recrystalliation method?
hello, why you did not use 5:1 DCM and Methanol? Also the dispersity of silica gel may be different from the TLC plate.
What is the Rf for TLC in 5:1 DCM/MeOH? 20% MeOH in DCM is kind of high already, better to show the reaction detail for better answer, your product may decompose on silica gel. 1:1 MeOH/DCM may elute some stuff from silica gel alone.
sir recommend me some other solvent except DCM and Methanol my compound is very polar
Try reverse phase? Use Acetonitrile or MeOH and water? Use C8-C18!
I do not know your reaction/product, not much to say!
Some compounds contain COOH may need 1%TEA to move on silica gel.
Dear colleague,
I believe that the separation of your synthesized compound on TLC plate and CC was totally different. I am for sure the resolution on TLC is higher because the silica particles are uniform, i.e the particle size are different. Your mobile phase used in CC must be weaker than the solvent used in TLC experiment. So I suggest that you should pack the column with silica fusion in DCM, and dissolve your sample in DCM or the mixture of DCM and MeOH (%MeOH < 20%), you should used air pump to push out and clean up the column with the loading solvent. And apply new mobile phase, start with 100 DCM, and use gradient solvent with the increasing of %MeOH. Hope everything go well.
I usually reduce the polarity of the mobile phase by a factor of 5 when using CC. For example, when I using TLC I need a mobile phase 5:1 DCM/MeOH. Therefore, to use CC, I need a 25:1 DCM/MeOH mobile phase. But this depends on the brand of silica gel and the brand of TLC plates.
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