By reaction of 1-(2,3-epoxypropyl)-2-nitroimidazole (I) with aziridine (II) in refluxing methanol.
[2H]-Labeled RSU-1069 is synthesized as follows: The condensation of 2-nitroimidazole (I) with 3-chloro-1,2-epoxypropane (II) gives 1-(3-chloro-2-hydroxypropyl)-2-nitroimidazole (III), which is oxidized with CrO3 - H2SO4 in acetone yielding 1-(3-chloro-2-oxopropyl)-2-nitroimidazole (IV). The reduction of (IV) with NaB[2H]4 in ethanol affords 1-(3-chloro-2-hydroxy-2(2H)-propyl)-2-nitroimidazole (V), which is cyclized with NaOH to the corresponding labeled epoxide (VI). Finally, this compound is condensed with aziridine (VII) by means of triethylamine in refluxing ethanol.
[2H]-Labeled pimonidazole is synthesized as follows: The condensation of 2-nitroimidazole (I) with 3-chloro-1,2-epoxypropane (II) gives 1-(3-chloro-2-hydroxypropyl)-2-nitroimidazole (III), which is oxidized with CrO3 - H2SO4 in acetone yielding 1-(3-chloro-2-oxopropyl)-2-nitroimidazole (IV). The reduction of (IV) with NaB[2H]4 in ethanol affords 1-(3-chloro-2-hydroxy-2(2H)-propyl)-2-nitroimidazole (V), which is cyclized with NaOH to the corresponding labeled epoxide (VI). Finally, this compound is condensed with piperidine (VII) in refluxing ethanol.