I prepared a pryrrolo [2,3-d] pyrimidin-2(5)-one compound using dihydroxybenzaldehyde and 1-methyl-2-pyrrolidone and monitor the progress of the reaction through TLC by dissolving aliquots of the reaction mixture at time intervals in methanol and taking TLC. At a certain stage of the reaction, it was no longer soluble in methanol nor any other solvent apart from DMF and DMSO which are not suitable solvent for TLC monitoring. I allow the reaction to continue for 2 hours and work up to remove the catalyst. The compound obtained is still not soluble in any other solvent apart from DMF and DMSO. It is difficult for me to grow crystals of this compound.
You might be able to dissolve the compound in a mixture of solvents. I have had luck using a combination of dichloromethane and ethanol (or methanol) to dissolve similar compounds. A ternary mixture of toluene, dcm and ethanol may also work (toluene will interfere with pi-stacking interactions, while the alcohol breaks up hydrogen bonding interactions). One possible advantage with the dcm/ethanol mixture is that slow evaporation of the dcm may produce crystals (if the compound is insoluble in ethanol alone)
Whether the compound is soluble in one of these mixed solvents, or whether you need to use dmf or dmso, if you can find a miscible antisolvent, diffusion crystallization might be the best way to proceed. This will be much easier for a toluene/dcm/ethanol mix (something like diethyl ether or pentane should work nicely as an antisolvent). For dmf or dmso, I might recommend cyclohexane, dioxane or ethyl acetate...
Good luck!
Dear
Ibanga Isaac
You may try using t-butanol, dioxan, THF or ethyl acetate as solvent of crystallisation.
Dissolve your sample in DMSO/DMF and add few mL of CHCl3 or DCM, keep it in refrigerator (below -10). You might have some luck there.
I sincerely appreciate all of you for your contributions. Diffusion crystallization really worked for me, I dissolve the compound in DMF and place it in tank containing DCM and left overnight and I got some crystals of the pure compound.
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