P-Toluenesulfonylhydrazide → Ethyl 1-cyclopropyl-3-methyl-4-methoxy-1H-indole-6-carboxylate

Participants

Reaction Steps

To a stirred solution of 3.30 g of ethyl 1-cyclopropyl-3-formyl-4-methoxy-1H-indole-6-carboxylate in 33 ml of EtOH was added 2.57 g of TsNHNH2 and the mixture was refluxed for 30 min. After evaporation of EtOH, the mixture was diluted with 28 ml of DMF and 28 ml of sulfolane, then 2.89 g of NaBH3CN and 0.57 g of TsOH H2O was added thereto successively. The mixture was refluxed for 30 min and cooled to room temperature. After diluted with Et2O, the mixture was washed successively with water, saturated NaHCO3aq, and saturated brine, dried over Na2SO4, concentrated. The residue was purified on SiO2 column chromatography (EtOAc/n-hexane system) to give 2.78 g of Ethyl 1-cyclopropyl-3-methyl-4-methoxy-1H-indole-6-carboxylate as a colorless powder.

Provenance & Evidence