Triethylamine → N-(4-methoxy-3-pyridyl)-4-oxo-4,5,6,7-tetrahydro-1H-indole 3-carboxamide

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Reaction Steps

To a stirring solution of 4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxylic acid (179 mg, 1 mmol) and triethylamine (293 μl, 2.1 mmol) in N,N-dimethylformamide (3 mL) at 0° C. was added ethyl chloroformate (191 μl, 2 mmol). After stirring an additional 30 minutes, a solution of 2-methoxy-5-amino-pyridine (216 mg, 2 mmol) in N,N-dimethylformamide (3 mL) was added. The reaction mixture was allowed to stir for an additional 75 minutes, then poured into saturated aqueous ammonium chloride and extracted 2× with ethyl acetate. The combined organic layers were washed with water, dried over magnesium sulfate, filtered, and concentrated in vacua. To the residue was added aqueous 5N sodium hydroxide (5 mL) and ethyl alcohol (1 mL), then heated at reflux for 1 hour. After cooling in an ice water bath, the reaction mixture was poured into saturated aqueous ammonium chloride and extracted 2× with ethyl acetate. The combined organic layers were dried over magnesium sulfate, filtered, concentrated in vacua, and the residue recrystallized from ethyl acetate to give N-(4-methoxy-3-pyridyl)-4-oxo-4,5,6,7-tetrahydro-1H-indole 3-carboxamide (56 mg); m. p. 209-210° C. (Compound 1).

Provenance & Evidence