I am trying to extract my products from DMSO without using the evaporation method. I tried mixing with water, then ether, and succeeded in the purification by filtration; this method has been reported before but for the extraction of DMSO (Attached). However, I want to understand what happens when I dilute DMSO with water, then adding a low boiling point organic solvent such as ether, which is initially immiscible with DMSO and water as well as not a solvent for my material?.
Hi
Sorry, but I don't understand your question.
The attached document shows the extraction of the compounds from a DMSO solution using ether without having DMSO extracted out into the ether. Isn't that what you wish to do?
The document shows a method for extraction of DMSO from reaction mixture containing water and ether. I follow the same method, but to separate my compounds from DMSO based on its extraction using a mixture of water and ether. Once it's extracted, I can separate the compounds as particles by filtration.
I want to understand what happens in this solvent mixture.
Hi
I believe the author of the documents provided an explanation at the last few paragraphs:
What is happening here is this: when the quenched mixture is initially extracted in funnel #1, most of the polar solvent goes into the water layer. Some product and ether are also partitioned into the water, and some polar solvent remains in the first ether layer. The aqueous layer moves into funnel #2 where it encounters fresh ether. This extracts product out of the water, and it may also take up some polar solvent. The process is repeated in each funnel.
Hope it helps.
Hi Eugene
I understand these steps, but want to know the importance of ether in that process, especially as my products aren't soluble in ether. Is that may be due to the extraction of part of DMSO in both water and ether layers?
Is your product found in the ether layer or the water layer? If your product is not soluble in both ether and water, I am not sure why you even to do the extraction. The addition of water alone should have cause the precipitation and you can filter directly and wash to dry.
No. It's insoluble in both.
Initially, in the paper, they concentrate the DMSO solution by evaporation, then precipitate the product using ether. I failed to evaporate a part of DMSO, so tried direct precipitation with ether, but need huge amounts of ether which couldn't precipitate much, but with addition of water, then ether, I could purify my product.
I also tried precipitation by adding water only but couldn't and got only emulsion-like mixture, and couldn't separate my product by filtration at all.
You can try adding hexane or petroleum ether to the DMSO solution. Less polar than ether and should be able to cause the product to precipitate out. Ether and DMSO should be fairly miscible and the product will not precipitate out.
Hope it helps
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