4-Methyl-3-nitroanisole was used as external standard in synthesis of antibody catalysts by bait and switch hapten strategy. It was used as starting material for synthesis of 4-fluoro and 2-fluoro-substituted acetylcholinesterase inhibitors. 4-Methyl-3-nitroanisole was used as external standard in synthesis of antibody catalysts by bait and switch hapten strategy. It was used as starting material for synthesis of 4-fluoro and 2-fluoro-substituted acetylcholinesterase inhibitors.