6-nitro-1H-indole-3-carbaldehyde → tert-butyl (Z)-4-({6-hydroxy-2-[(6-nitro-1H-indol-3-yl)methylene]-3-oxo-2,3-dihydrobenzofuran-7-yl}methyl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of tert-butyl 4-[(6-hydroxy-3-oxo-2,3-dihydrobenzofuran-7-yl)methyl]piperazine-1-carboxylate (0.050 g, 0.14 mmol) obtained in Example A16, Step 1 in methanol (2.0 mL) was added with 6-nitro-1H-indole-3-carboxaldehyde (0.026 g, 0.14 mmol). Then, the mixture was added with 5 drops of piperidine, and the mixture was stirred at 50° C. for 2 hours. The solvent was evaporated under reduced pressure, and then the residue was washed with a mixed solvent of chloroform and methanol to obtain tert-butyl (Z)-4-({6-hydroxy-2-[(6-nitro-1H-indol-3-yl)methylene]-3-oxo-2,3-dihydrobenzofuran-7-yl}methyl)piperazine-1-carboxylate (0.049 g, 67%).

Provenance & Evidence