反应详情

A second related synthesis route provided for hydrogenation of the 5-nitrobenzofuran-2-carboxylic acid ethyl ester with Raney nickel and H2 in MeOH to give the corresponding compound of 5-aminobenzofuran with bis(2-chloroethyl) amine in dichloromethane to give 5-(1-piperazinyl)-benzofuran-2-carboxylic acid ethyl ester. The reaction of the latter compound with di-tert-butyl dicarbonate in THF provides the protected amino compound 5-[4-(tert-butoxycarbonyl)-1-piperazinyl]benzofuran-2-carboxylic acid ethyl ester, which is first reacted with formamide and sodium alkoxide in N-methylpyrrolidone to provide the corresponding amide, and then deprotected by treatment with HCl/MeOH to give 5-(1-piperazinyl)benzofuran-2-carboxamide. Finally, this amide is condensed with 3-(4-chlorobutyl)-1H-indol-5-carbonitrile to give vilazodone.