To provide a method for producing a 3-substituted 2-chloro-5-fluoro-pyridine or its salt in high yield from a readily available material through a short process under mild reaction conditions using a reagent which is easy for handling and simple in the reaction operation. Namely, a method for producing the following compound (2) or its salt which comprises selectively reducing a chlorine atom at the 6-position of the following compound (1) or its salt, is provided. Further, a method for producing the following compound (4) or its salt which comprises substituting a Z
1
group of the following compound (2) or its salt obtained by the reduction reaction, by a Z
2
group, is provided. Here, Z
1
is —CO
2
R
1
, etc., and R
1
is a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group or a cycloalkyl group. Z
2
is a group different from Z
1
and is —CO
2
R
5
, etc., and R
5
is an alkyl group, an alkenyl group, an aryl group, an aralkyl group or a cycloalkyl group.
提供一种从易得材料经过短时间过程,在温和反应条件下,使用易于处理且反应操作简单的试剂高产率制备3-取代的2-
氯-5-
氟吡啶或其盐的方法。即提供一种制备以下化合物(2)或其盐的方法,该方法包括选择性还原以下化合物(1)或其盐的6位
氯原子。此外,提供一种制备以下化合物(4)或其盐的方法,该方法包括用Z2基取代通过还原反应获得的以下化合物(2)或其盐的Z1基。这里,Z1是—CO2R1等,R1是氢原子、烷基、烯基、芳基、芳烷基或环烷基。Z2是与Z1不同的基团,是—CO2R5等,R5是烷基、烯基、芳基、芳烷基或环烷基。