2) The condensation of 4-nitrobenzyl bromide (VI) with 1,2,4-triazole sodium salt (VII) in DMF gives 1-(4-nitrobenzyl)-1,2,4-triazole (VIII), which is reduced with H2 over Pd/C in ethanol/ethyl acetate yielding the aniline (I). The diazotization of (I) with NaNO2/HCl followed by reduction with SnCl2 affords the corresponding hydrazine (IX), which is cyclized with 4-chlorobutanal dimethylacetal (X) by means of HCl in refluxing ethanol/water to afford 2-[5-(1,2,4-triazol-1-ylmethyl)-1H-indol-3-yl] ethylamine (XI). Finally, this amine is methylated with formaldehyde, sodium cyanoborohydride and acetic acid in methanol.
3) The condensation of 4-nitrobenzyl bromide (VI) with 4-amino-1,2,4-triazole (XII) in refluxing isopropanol gives 4-amino-1-(3-nitrobenzyl)-1,2,4-triazolium bromide (XIII), which is deaminated with NaNO2/HCl to afford 1-(4-nitrobenzyl)-1,2,4-triazole (VIII). The reduction of (VIII) yields amine (I), which by diazotation and reduction with Na2SO3 yields the corresponding hydrazine (IX). Finally, (IX) is cyclized with 4-(dimethylamino)butanal dimethylacetal (XIV) in acidic water.
1) The iodination of 4-(1,2,4-triazol-1-ylmethyl)aniline (I) with ICl and CaCO3 in methanol/water gives the 2-iodoaniline (II), which is cyclized with 1-(triethylsilyl)-4-(triethylsilyloxy)-1-butyne (III) by means of paladium acetate and Na2CO3 in hot DMF yielding 5-(1,2,4-triazol-1-ylmethyl)-3-[2-(triethylsilyloxy)ethyl]-1H-indole (IV). The desilylation of (IV) with HCl in methanol affords the corresponding alcohol (V), which is condensed with dimethylamine by means of methanesulfonyl chloride and triethylamine to give MK-0462 free base (VI). Finally, this compound is treated with benzoic acid in isopropyl alcohol/isopropyl acetate solution.