PREPARATION OF CHLORONICOTINIC ACID TYPE COMPOUND

PURPOSE:To obtain advantageously the titled compound, by reacting a trifluoromethylpyridine type compound with aluminum chloride in the presence of a chemically inert solid inorganic compound, and hydrolyzing the reaction product in the presence of nitric acid or phosphoric acid. CONSTITUTION:A compound of formula I (X1-X3 are H or Cl, at least one of X1 and X3 is Cl) is reacted with aluminum chloride in the presence of a chemically inert solid inorganic compound, particularly potassium chloride, sodium chloride, potassium sulfate, sodium sulfate, silica powder or silica sand, to give a compound of formula II, which is then hydrolyzed in the presence of nitric or phosphoric acid to afford the aimed compound of formula III in high purity and yield easily and in a short reaction time. The aimed compound is obtained from the economically available raw materials which have been industrially prepared with side reactions not so much, and the intermediate is stable to give the high purity and yield.