avl Posted April 1, 2013 Posted April 1, 2013 Hello! I'm going to be following a procedure for a reflux reaction and I'm a bit confused on the directions after refluxing for 8 hours. My desired product after refluxing will be a liquid. I'm confused about which "residue" that will be dissolved in ethyl acetate: the liquid product or the solid collected with the celite filter aid. Assuming that everything in bold was done to my liquid solvent collected from vacuum filtration, is it asking to do a second vacuum filtration to remove the drying agents? Also, what's the purpose of adding ethyl acetate to my solution? My theoretical yield should be 1.76 mL of pure Allyl Phenyl Ether. It seems odd to add such a large amount of liquid even though my product is only 1.76 mL. How will it be separated from the product? Here is the procedure: "As a general procedure, to the solution of phenols (1a-h) (20 mmol) in anhydrous acetone (20 mL) was added anhydrous K2CO3 (30 mmole), and allyl bromide (22 mmol). The reaction mixture was stirred and under reflux for 8 h. Then it was filtered through celite 545 under suction, and the filtrate was concentrated in vacuo. The residue was dissolved in ethyl acetate (100 mL), washed with saturated NaCl, and then dried in MgSO4. After filtration, the solvent was removed in vacuo to give crude 2a-h, which was further purified by silica gel chromatographic column (ethyl acetate/nhexane = 1/8)." Thanks for your help!
Knumbnuts Posted April 1, 2013 Posted April 1, 2013 The first filtration is to remove salts. You then take the filtrate (the liquid in the flask) and remove the acetone. The residue left after this evaporation is dissolved in ethyl acetate and washed to remove any further salts. You add magnesium sulphate to dry the ethyl acetate/product solution and remove the magnesium sulphate by filtration. The filtrate is then evaporated to remove the ethyl acetate and the residue chromatographed. 2
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now