PURPOSE: To obtain a compound useful as a synthetic intermediate for thiadiazabicyclononane-based herbicides by hydrolyzing thioacetates and reacting the hydrolyzate with an haloacetic acid methyl ester and then reducing the resultant product.

CONSTITUTION: S-(2-Chloro-4-fluoro-5-nitrobenzene)thioacetate is hydrolyzed using a mineral acid (e.g. hydrochloric acid) to afford 2-chloro-4-fluoro-5- nitrothiophenol, which is then reacted with a haloacetic acid methyl ester in the presence of a base (e.g. triethylamine) in a solvent such as dichloromethane to give S-(2-chloro-4-fluoro-5-nitrobenzene)thioacetic acid methyl ester. Then the compound is reduced with iron powder and mineral acid to provide the objective S-(5-amino-2-chloro-4-fluorobenzene)thioacetic acid methyl ester.