The N-protection of 4-amino-1-naphthol (I) with Boc2O by means of BuLi in THF gives the carbamate (II), which is condensed with 4-(2-chloroethyl)morpholine (III) by means of K2CO3 in hot acetonitrile, yielding the corresponding aryl ether (IV). The deprotection of the amino group of (IV) with HCl in dioxane affords the naphthylamine (V), which is finally condensed with 3-(tert-butyl)-1-(4-methylphenyl)-1H-pyrazole-5-amine (VI) by means of COCl2 in toluene/dichloromethane and aq. NaHCO3 to provide the target urea. The intermediate 3-(tert-butyl)-1-(4-methylphenyl)-1H-pyrazole-5-amine (VI) is obtained by cyclization of 4-methylphenylhydrazine (VII) with 4,4-dimethyl-3-oxopentanenitrile (VIII) by means of HCl in refluxing ethanol.
The cyclization of 4-methylphenylhydrazine (I) with pivaloylacetonitrile (II) in refluxing methanol gives the aminopyrazole (III), which is treated with Troc-Cl and NaOH in water/ethyl acetate to yield the carbamate (IV). Finally, this compound is condensed with 4-[2-(4-morpholinyl)ethoxy]naphthalene-1-amine (V) by means of DIEA in hot DMSO to afford the target urea. The intermediate 4-[2-(4-morpholinyl)ethoxy]naphthalene-1-amine (V) is obtained by condensation of 2-(4-morpholinyl)ethanol (VI) with 4-nitro-1-naphthol (VII) by means of NaOH and K2CO3 in hot 1-methyl-2-pyrrolidone to yield the corresponding ether (VIII), which is finally reduced with H2 over Pd/C in methanol.
The reaction of 4-amino-1-naphthol (I) with Boc2O in THF gives the carbamate (II), which is condensed with 4-(2-chloroethyl)morpholine (III) by means of K2CO3 in hot acetonitrile to yield ether (IV). The hydrolysis of the carbamate group of (IV) by means of HCl in dioxane affords the naphthylamine (V), which is finally condensed with 3-tert-butyl-1-(4-methylphenyl)-1H-pyrazol-5-amine (VI) and phosgene (VII) in THF to provide the target urea. The intermediates 3-tert-butyl-1-(4-methylphenyl)-1H-pyrazol-5-amine (VI) and phosgene (VII) are obtained by cyclization of 4-methylphenylhydrazine (VIII) with 4,4-dimethyl-3-oxopentanenitrile (IX) in refluxing toluene or by means of HCl in refluxing ethanol.