Crooked way, ethyl acetate vs water, ultrasonic shock helps high-boiling oil crystallization
Chemical experimental operation method
Operation steps
The specific operation method is as follows, and the applicability of this operation is at the bottom
- In the spin-dried high-boiling oil system, add water and ethyl acetate at will
- Ultrasound vibrates all the time, keeps shaking (Ps: my hand hurts when I shake, and the top gifter with mechanical stirring can be used by machine)
- Shake out system status:
- Let stand overnight (or directly down), filter, collect the filter cake separately, separate the filtrate, and extract the water layer with ethyl acetate at one time to obtain:
Purity monitoring TLC:
Applicability points
- The polarity of the product should be larger, preferably water-insoluble or insoluble, ethyl acetate insoluble or slightly soluble, the ratio of dichloromethane to methanol can be dissolved, and TLC also requires the ratio of dichloromethane to methanol.
- The product should be determined to be a solid and the main component of the system. It cannot be that the proportion of impurities is relatively large. Do not do useless work
- The principle is very simple, two beggars, a bowl of stinky rice, there is always one person to eat, eat until the stomach can't stand it, cycle a bit, and spit out the insoluble stomach.
- When the impure product is an oil, the crystallization effect is better than when it is a solid. It feels that the oil will have a complete dissolution process, while when it is a solid, some of it does not enter the solvent.
- Due to the large number of impurities in the filtered mother liquor, it may also play a dissolving effect. At this time, the filtrate can be mixed with silica gel and passed through the column, or it can be concentrated and shaken for another round
- A method is such a method, it can only be understood without words.
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