In the synthesis of certain 7-hydroxycoumarin conjugated by an amide bond with 5-fluorouracil, the used solvent (DMSO) has distilled off under reduced pressure. The product was still sticky and the FTIR spectrum indicated the presence of the solvent with the product. How can removed that solvent from the product?
Dear Frank T. Edelmann
Thank you very much. Your answer is highly valuable.
Regards
Dear Yasser Fakri Mustafa, depending on the solubility of your product, I would try to triturate the sticky residue e.g. with cold diethyl ether. In detail, you could add pre-cooled (–78 °C) diethyl ether and stir the mixture with a glass rod. Chances are that under these conditions only the residual DMSO dissolves in the diethyl ether and can be separated by decantation. Good luck!
Dear Frank T. Edelmann
Thank you very much. Your answer is highly valuable.
Regards
Dear Yasser Fakri Mustafa
You can wash the product for several times with cold water.
All the best
Dear Yasser Fakri Mustafa
You can suspend the product in water and then distilled the mixture under reduced pressure. This process may be repeated several times until the product becomes free from DMSO.
All the best
Dear Raeid Khalil
Thank you for your kind contribution.
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Dear Mohammed Emam
Thank you for your kind contribution.
Regards
Dear all, the inverse strategy is also possible, i.e., to take off the product from the solvent. Both DMSO and DMF present difficulty to get rid of them. So solvent extraction seems to be the best alternative issue. This avoid excessive heating that may lead to the degradation (especially hydrolysis) of the product. My Regards
Dear Abdelkader BOUAZIZ
Yes, it is also possible. Thank you very much for your answer.
Regards
Dear Yasser Fakri Mustafa I completely agree with answer provided by Frank T. Edelmann . My regards.
DMSO is hygroscopic, and in my experience trituration with a solvent that can dissolve at least some amount of water is often more effective. THF, dioxane, acetonitrile, acetone, and isopropanol can all be tried, so long as your product isn't highly soluble in the chosen solvent.
Dear Mahmood Khudhayer Oglah
Thank you for your kind contribution.
Regards
Dear James Demers
Thank you for your kind contribution and valuable opinion.
Regards
Solvent Removal
It is often necessary to remove solvent from a solution to recover either a solid or a high-boiling liquid. There are several ways to do this.
Distillation
Simple distillation can be used to remove solvent. Distillation works well if the solution is composed of a solid and a low-boiling solvent, or if the solution is composed of a high-boiling liquid and a low-boiling solvent (with boiling point differences greater than 100°). Advantages of distillation are that the solvent can be collected and recycled and that no vapors are released into the atmosphere. A disadvantage is that it can take a long time. Simple distillation is covered on the simple distillation web page.
Open-Dish Evaporation
Solvent can be evaporated by placing the solution in an open container (an Erlenmeyer, evaporating dish, beaker, vial). The container is set on a heat source (steam bath, hot plate, heating mantle, sand bath) and the solvent boiled off. (If the solvent is water, use a heat source other than a steam bath.)
The problem with open-dish evaporation is that the solvent is released into the air. Open-dish evaporation should always be done in a hood if the solvent is anything other than water. Even in a hood, however, vapors are released into somebody's air. If the solvent is a hazardous compound (for instance, methylene chloride), it is probably better to choose another method of solvent removal.
Reduced-Pressure Evaporation
You can accomplish evaporation from a solution quickly by placing it in a side-arm flask, sealing the flask, and then applying vacuum. Under vacuum (reduced pressure) liquids vaporize and boil off at lower temperatures; effectively, the solvents come off a lot faster when under vacuum than at atmospheric pressure.
In the Organic Chemistry Teaching Labs, a small (25 or 50 mL) side-arm flask fitted with a rubber stopper is used to strip off small (5-10 mL) amounts of solvent. As a vacuum source, we use the VacuuBrand systems.
You can removed the solvent from the product by washing with methanol & then dry under vacuum.
Dear Nasser Said Gomaa Abdelrasheed
Thank you very much for your valuable information.
Regards
Dear Madhukar Baburao Deshmukh
Thank you very much for your kind contribution.
Regards
You may find also useful this RG thread: https://www.researchgate.net/post/How_can_I_remove_DMSO_from_my_sample_Ive_done_washing_with_water_and_extracting_with_DCM_and_also_freeze-drying_but_they_were_inefficient/1
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