AHR-53338 is synthesized in an overall yield of 62% from ethyl isonipecotate (I): Ethyl isonipecotate (I) is protected with benzyl bromide (II) to give (III), which is then treated with 2.5 moles of 4-fluorophenylmagnesium bromide to give the tertiary alcohol (IV). The benzyl group is removed by catalytic hydrogenolysis to give the secondary piperidine (V). The reaction of 1-bromo-3-chloropropane (VI) with acetovanillone (VII) gives 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone (VIII) in excellent yield. A mixture of (V) and (VIII) in 1-butanol and triethylamine heated at reflux yields AHR-53338 isolated as the mandelic acid salt.

AHR-53338 is synthesized in an overall yield of 62% from ethyl isonipecotate (I): Ethyl isonipecotate (I) is protected with benzyl bromide (II) to give (III), which is then treated with 2.5 moles of 4-fluorophenylmagnesium bromide to give the tertiary alcohol (IV). The benzyl group is removed by catalytic hydrogenolysis to give the secondary piperidine (V). The reaction of 1-bromo-3-chloropropane (VI) with acetovanillone (VII) gives 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone (VIII) in excellent yield. A mixture of (V) and (VIII) in 1-butanol and triethylamine heated at reflux yields AHR-53338 isolated as the mandelic acid salt.