I am synthesizing a compound. The protocol says, that the product should be washed with water, extracted using ethyl acetate and then purified by silica gel column chromatography. The product is not a precipitate. It is liquid, soluble in both water and ethyl acetate. When I add water to the product and then add ethyl acetate to it, two layers are formed. Very little compound comes into ethyl acetate. So, how should I proceed? New to chemical synthesis.
Multiple Extraction is best way to get better recovery. You have to use fresh ethyl acetate at every time and minimum 4 time.
My opinion is that the crude product is dissolve in dichloromethane or chloroform and then do the column chromatography to separate the product.
Dear Kumar,
Washing your mixture with water is often means separating your compound with your reagent that soluble in water such as base / acid and and it means that your compound isn't pure yet. You need to extract it with ethyl acetate multiple times so you could get better yields. But if it remains the same, then that's your product. It's often that you would get less yield than in your reference paper, because difference in condition, personal experience and such. But to be sure it's the same compound as in your reference, you need to compare the Rf between your compound and your reference compound using the same eluent. Your reference paper would surely provide such information.
Good luck with your synthesis
Regards,
Didy Yoga
Dear Kumar
Add brine to the sample and try to extract your sample using Ethyl Acetate. Using Brine will decrease your sample solubility in water and as a result the sample is extracted using EtOAc.
Wash your sample 3 to 4 time using Brine solution.
Best of Luck.
Nadeem
If your protocol says to wash with water then give just very light wash with cold water first, then wash with ethaylacetate in fractions, collect fractions and evaporate or distill ethylacetate.
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