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Klute
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Registered: 18-10-2006
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Arg, such a pity I didn't think about it earlier... Too bad, I hope the methyl salicylate goes well!
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
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DJF90
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I'll type up the prep. for thise interested:
Add to a 50ml pear-shaped flask 9g of 2-hydroxybenzoic acid (salicylic acid), 15ml of methanol, and 2ml of concentrated sulphuric acid. Fit the flask
with a reflux condenser and boil the mixture for about an hour.
Cool the mixture to room temperature and pour ir inro a separating funnel (we used a 50ml sep funnel) that contains 30ml of cold water. Rinse the
flask with 15ml of ethyl ethanoate and add this to the separating funnel.
Mix the contents of the serarating funnel and allow them to settle; if an emulsion forms try adding a little more solvent (the EtOAc). Run the lower
aqueous layer into a conical flask.
Wash the organic solvent extract in the separating funnel with 30ml 0.5M aqueous sodium carbonate, carefully releasing the pressure in the separating
funnel frequently as there is likely to be considerable evolution of carbon dioxide. Separate the aqueous and organic layers by running into seperate
small conical flasks. The aqueous layer can be discarded (I can't remember if this is the upper or lower layer... you'll have to find out for yourself
I'm afraid).
Dry the organic solvent extract with solid anhydrous sodium sulphate. Leave to dry for about 10 minutes while you set up the apparatus for simple
distillation. Then remove the sodium sulphate by filtering. Remove the organic solvent by distillation (ethyl ethanoate boils at 77C). Complete the
distillation, collecting the distillate boiling above 220C as oil of wintergreen (medical name I think); methyl salicylate.
I also have a prep. for aspirin on the opposite page if anyone is interested.
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S.C. Wack
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Everyone does methyl salicylate. If I was asked "what is the most tired synthesis in modern lab manuals?", this ester would be my reply OTOH.
Why start with chloroacetic acid for diethyl malonate? Why not start with malonic acid?
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Tsjerk
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If you are going for a high yield (which looks nice in your report), you can use a big excess of methanol since it's easily separated afterwords duo
the high boiling point of wintergreen.
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