Pyridine → 3-Amino-5-cyano-3-(2-ethoxyphenyl)indol-2-one

Participants

Reaction Steps

8.0 g (27.2 mMol) of intermediate 1b and 43 ml (54.4 mMol) of pyridine were dissolved in 70 ml of methylene chloride. Then, at 0° C., 3 ml (40.8 mMol) of SOCl2 were slowly added dropwise. The reaction mixture was then stirred for a further 30 minutes. The reaction solution was subsequently poured into ice-water, and the organic phase was separated off, washed with water, dried and concentrated in vacuo. This residue was added at 0° C. to a solution of 300 ml of 0.5M NH3 solution in dioxane and 150 ml of methylene chloride. The mixture was stirred at room temperature for 16 h. The reaction solution was concentrated in vacuo, and the residue obtained in this way was suspended in water. The precipitate was separated off and recrystallized from a little methanol. 4.7 g of the product were obtained.

Provenance & Evidence