PURPOSE: To obtain the subject compound in high purity and high yields by a short step by reacting 3-chloroanthranilic acid with phosgene in an inert organic solvent to form 3-chloroisatoic anhydride and reacting this with an alkanol.

CONSTITUTION: 3-Chloroanthranilic acid of formula I is reacted with 0.8-5 pts.wt. phosgene in an inert solvent to obtain 3-chloroisatoic anhydride of formula 2. Next, the 3-chloroisatoic anhydride is reacted with an alkanol in the presence of optionally a esterification catalyst to obtain a 3-chloroanthranilic acid alkyl ester of formula 3 (wherein R is an alkyl). The inert solvent is exemplified by especially toluene, xylene, a xylene isomer mixture, chlrobenzene, dichlorobenzene or chlorotoluene. The esterification catalyst is exemplified by especially hydroxides, carbonates and hydrogencarbonates of sodium and/or potassium. The 3-chloroanthranilic alkyl ester is useful as an important intermediate for producing pharmaceuticals and agricultural chemicals.