Suzuki coupling of 4-bromonaphth-1-ylamine (I) with 4-pyridylboronic acid (II) furnished 4-(pyridyl)-1-naphthylamine (III), which was further converted into isocyanate (IV) by treatment with triphosgene.

Catalytic hydrogenation of 1-acetyl-6-nitroindoline (V) afforded amine (VI). Condensation of (VI) with mechlorethamine hydrochloride (VIII) in the presence of K2CO3 in refluxing n-butanol produced piperazinylindoline (X). Alternatively, intermediate (X) was obtained by Sandmeyer reaction of amine (VI) in the presence of CuBr, followed by condensation of the resulting bromide (VII) with N-methylpiperazine (IX). Chlorination of (X) with N-chlorosuccinimide provided (XI). The acetamide function of (XI) was then hydrolyzed in refluxing 2M HCl to give amine (XII). Finally, coupling of (XII) with isocyanate (IV) gave rise to the corresponding urea.

Suzuki coupling of 4-bromonaphth-1-ylamine (I) with 4-pyridylboronic acid (II) furnished 4-(pyridyl)-1-naphthylamine (III), which was further converted into isocyanate (IV) by treatment with triphosgene.

Catalytic hydrogenation of 1-acetyl-6-nitroindoline (V) afforded amine (VI). Condensation of (VI) with mechlorethamine hydrochloride (VIII) in the presence of K2CO3 in refluxing n-butanol produced piperazinylindoline (X). Alternatively, intermediate (X) was obtained by Sandmeyer reaction of amine (VI) in the presence of CuBr, followed by condensation of the resulting bromide (VII) with N-methylpiperazine (IX). Chlorination of (X) with N-chlorosuccinimide provided (XI). The acetamide function of (XI) was then hydrolyzed in refluxing 2M HCl to give amine (XII). Finally, coupling of (XII) with isocyanate (IV) gave rise to the corresponding urea.