| 摘要 |
PURPOSE:To obtain a pyridoxine derivative in high yield without forming by- products under mild conditions, by treating a specific compound with a hard acid and a soft base. CONSTITUTION:A compound of formula I (R1 and R2 are lower alkyl) or a mineral acid salt thereof is mixed with a hard acid and a soft base in molar amounts of about 3 times or more of the compound of formula I or a mineral acid salt thereof if necessary in a solvent, e.g. acetic acid, at room temperature for several hours - several tens of hours under agitation to give a pyridoxine or a mineral acid salt thereof. The hard acid includes AlCl3, AlBr3, boron tribromide or boron tribromide complex salt, etc. having a high positive charge of an electron accepting atom, small size and no easily excitable outer shell electron, and bonding strongly to a base having a great tendency toward bonding to proton, and the soft base includes easily oxidizable ethyl mercaptan, methyl sulfide or NaI, etc. having strongly polarized electron donative atoms, low electronegativity, and capable of associating with vacant orbits of low energy.
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