合成路线1

The bromination of styrene (II) with N-bromosuccinimide in the presence of cyanamide (I) provided 2-bromo-1-phenylethylcyanamide (III). Further addition of MeOH to (III) in the presence of HCl, followed by Na2CO3-promoted cyclization, produced the methoxyimidazoline (IV). Acylation of indoline (V) with trifluoroacetic anhydride and pyridine gave amide (VI) and subsequent chlorosulfonation yielded sulfonyl cloride (VII). This acid chloride was coupled to imidazoline (IV) in the presence of NaHCO3 in aqueous acetone to furnish a mixture of sulfonyl imidazolines (VIII) and (IX). The major isomer (IX) was isolated by column chromatography, and then, hydrolysis with HCl in MeOH at r.t. provided imidazolidinone (X). The trifluoroacetamide group of (X) was further hydrolyzed by treatment with NaOH in aqueous MeOH to give (XI). Subsequent condensation of (XI) with 4-nitrobenzoyl chloride (XII) in the presence of pyridine yielded 4-nitrobenzamide (XIII), which was finally reduced to the aminobenzamide by hydrogenation using Raney-nickel as the catalyst.