sYnThOmAtIc (Hive Addict)
09-10-02 04:37
No 354769
      Dipolar aprotic solvent selection???? Electro-epox  Bookmark   

Ok in the sodium bromide assisted electro-epoxidation they say to use a dipolar aprotic solvent. Now I know that a diploar aprotic solvent is a solvent capable of dissolving ionic substances because of the presence of a dipole, which allows the formation of an ion-dipole force bond and that a short list of these solvents are MEK, acetone, DMSO, DMF, Acetonitrile, EtOAc, and some others that are to non polar and would probably give low yields. Now the two solvents that were stated to be preffered are MeCN and DMF. Now ethyl acetate is too time consuming to make and would have o-h bond containing comtaminats and it's dipole moment and dielectric constant are too low. Formamide, DMSO, acetone and MEK in that order are next in preference to their dipolar properties. The first two again being too hard obtianed. Now my friend had success using mek a while back which everybody denoted. But it was quite unrealiable  it would yield good then nothing at all. My main question is of acetone and mek would any of them be oxidized or react with the free br ions to form any nasty chemicals or such that would interfere with the reaction particularly the iso or epoxide. Now I have heard of bromoacetone and it doesn't sound too wonderful but I believe that such a chemical would not be easily made under these mild conditions but am unsure since I know little to nothing chemical niteractions and such.

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