| 摘要 |
1-(Pyridinyl)-1,1-dialkoxy-1-aminoethane derivatives are prepared by converting acetylpyridine to an acetylpyridine oxime metal salt; reacting the oxime metal salt with a solution of p-toluenesulfonic acid derivative to give an acetylpyridine tosyl oxime; and reacting the tosyl oxime with a mixture of an alkali metal alkoxide, an alkali metal hydroxide, an alkaline earth metal alkoxide or an alkaline earth metal hydroxide with an alcohol. Preparation of 1-(pyridinyl)-1,1-dialkoxy-1-aminoethane derivatives of formula (I), involves: (i) converting acetylpyridine of formula (V) using an aqueous solution of a hydroxylammonium compound or an aqueous solution of hydroxylamine, in the presence of an inorganic base, to an acetylpyridine oxime metal salt of formula (IX); (ii) reacting the acetylpyridine oxime metal salt with a solution of p-toluenesulfonic acid derivative of formula (X) containing a leaving group Y, in a suitable solvent that is water-immiscible or sparingly water-soluble or water-insoluble to give an acetylpyridine tosyl oxime of formula (XI); (iii) reacting the acetylpyridine tosyl oxime with a mixture of an alkali metal alkoxide, an alkali metal hydroxide, an alkaline earth metal alkoxide or an alkaline earth metal hydroxide with an alcohol to produce a compound of formula (I); and (iv) conducting the process continuously or batchwise independently for each process step (converting step and reacting steps). The reaction proceeds in a biphasic mixture of water and suitable solvent, optionally with the use of one or more phase transfer catalysts. The alkoxide is R 1>O -> or R 2>O ->. The alcohol is R 1>OH or R 2>OH. [Image] R 1>, R 2>straight-chain or branched (1-6C) alkyl; or R 1>+R 2>together with the oxygen atoms form a cyclic ketal, where together they are 2-4C alkylidene; n : 1 or 2; M n+>alkali metal or alkaline earth metal ion;and Y : F, Cl or Br. The pyridine radical is substituted in the 2-, 3- or 4-position. |
