The invention discloses a method for preparing 2-alkoxy4-amino5-chlorobenzoic acid, which includes steps of sequentially carrying out
acylation reaction, Kolbe-Schmitt reaction,
esterification reaction and etherification reaction for compound 3-amino-4-
chlorophenol to obtain a compound represented by formula G, and carrying out
alkaline hydrolysis to the G. By employing the cheap 3-amino-4-
chlorophenol as
raw material, the invention avoids using of expensive NCS, greatly reduces
raw material cost, and avoids safety and
environmental protection hidden trouble caused by NCS employed by prior art; by introducing
solvent to Kolbe-Schmitt reaction, yield of the reaction is greatly increased, cost is lowered, needed pressure is greatly reduced, and equipment investment of industrial production and safety hidden trouble due to
high pressure reaction are reduced; in addition, the
esterification reaction and the etherification reaction are carried out for one step, thereby avoiding production equipment
corrosion problem caused by employing common esterification method, namely strong acid condition under
catalysis of concentrated
sulfuric acid or
hydrogen chloride gas, and further reducing cost.