This report described that a hapten of racemic phosphonate 3 designed as the mimic of the transition state of hydrolysis of naproxen ethyl ester was successfully synthesized from easily available 2-acetyl-6-methoxy-naphthalene 5. Then BALB/C mice were immunized and one of the monoclonal catalytic antibodies, N116-27, which enantioselectively accelerated the hydrolysis of the R-(−)-naproxen ethyl ester was given. The Michaelis– ...